Special thanks are due to Volkswagen of America and its many kind and patient staff who helped us over many hurdles we would not have been able cross on our own. Mr Rudi Spielberger and his staff of service training instructors provided a great deal of insight into the brand-new Turbo models and also various lips and hints on making difficult tasks more understandable to the home mechanic. Their time is appreciated.

Ogner Porsche-Audi of Woodland Hills, California provided not only parts, but the time of their service people. We were able to pick up some simple shortcuts in the performing of basic tasks.

Dean Banks of Beck-Arnley Corporation provided us with his Porsche 924 and patiently endured our tampering with his car.

Several other people contributed much time and research in helping us get the most complete information available for this pro- ject. Even though we do not have the space to thank each one personally they know who they are.

Every care has been taken to provide the most complete and up-to-date information available on the repair and care of the Porsche 924. Although much time has been spent ensuring the correctness of the information in this manual, it must be understood that Porsche, as a manufacturer, is continually making minor improvements and detail changes to its production vehicles. These cannot be detailed exactly or completely.

We are proud of the thoroughness of the work that has gone into this manual, and of the excellent work carried out by our mechanics, Henry 'Spook' Caspers and Tom Schauwecker. Our thanks must also go to all those people at Sparkford, England who assisted in the production of this manual. However, no liability can be accepted by the authors or the publishers for loss, damage, or injury caused by errors in, or omissions from, the information contained in this manual.

About this manual

Its aim
 

The aim of this book is to help you get the best value from your car. It can do so in two ways. First it can help you decide what work must be done, even should you choose to get it done by a service station. It will also enable you to carry out routine maintenance tasks, and the diagnosis and course of action when random faults occur. However it is hoped that you will also use the second and fuller purpose by tackling the work yourself. This is not only satisfying, but on the simpler jobs it may even be quicker than booking the car into a service station and going there twice, to leave and collect it. Perhaps most important, much money can be saved by avoiding the costs a service station must charge to cover labour and overheads. To avoid labour costs a service station will often give a cheaper repair by fitting a reconditioned assembly. The home mechanic can be helped by this book to diagnose the fault and make a repair using only a minor spare part.

The book has drawings and descriptions to show the function of the various components so that their layout can be understood. Then the tasks are described and photographed in a step-by-step sequence so that even a novice can cope with complicated work. The jobs are described assuming only normal tools are availa- ble, and not special tools unless absolutely necessary. However a reasonable outfit of tools will be a worthwhile investment. Many special workshop tools produced by the makers merely speed the work, and in these cases guidance is given as to how to do the job without them. On a very few occasions a special tool is essential tc prevent damage to components; then its use is described. Though it might be possible to borrow the tool, such work may have to be entrusted to the official agent.

Using the manual

The manual is divided into twelve Chapters. Each Chapter is divided into numbered Sections which are headed in bold type between horizontal lines. Each Section consists of serially num- bered paragraphs.

There are two types of illustrations: (1) Figures which are num bered according to the Chapter and sequence of occurrence in that Chapter. (2) Photographs which have a reference number in their caption. All photographs apply to the Chapter in which they occur so that the reference figure pinpoints the pertinent Section and paragraph number.

Procedures, once described intext, are not normally repeated. If it is necessary to refer to another Chapter the reference will be given. Cross-references given without use of the word 'Chapler' apply to Sections and/or paragraphs in the same Chapter, eg, 'see Section 8' means also 'in this Chapter'.

When the left or right side of the car is mentioned it is as if one is seated in the driver's seat looking forward.
 

The 924 differs from earlier Porsche designs in several signifi- cant ways. First, and the most obvious change, is the use of a water-cooled engine mounted at the front of the vehicle. The engine is not bolted directly to the transmission, that unit being found at the rear of the vehicle as a transaxle. This design feature gives the 924 a nearly perfect weight distribution and enhances the handling capabilities of the car.

Other features of the vehicle are unitized construction, fully- independent suspension, and redesigned seating. Some of the fea- tures are not new to Porsche, but an extension of previous styling practices.

The North American market versions of the 924 have the most variations. There are very few options available on these models. Options are generally limited to wheels, tires, air conditioning, and suspension options. The main difference between years and markets is in the engine.

From 1976 through 1977 1/2 model years. North American ver- sions of the 924 had engines of 95 hp. This was a result of fitting low compression pistons and the addition of emission control systems. The emission controls which were used vary according to the sales market. They are described in greater detail elsewhere in this manual.

Early North American models were fitted with a 4-speed gear- box, but an automatic transmission became an option in 1977.

A redesign of the emission controls and the higher-com- pression pistons brought the engine output to 110 hp in the 19771/2 through 1979 models. Emission controls continued to vary accord- ing to the sales market.

The 4-speed gearbox was retained until the Introduction of the 1979 models, when it was replaced with a 5-speed unit. The auto- matic transmission remained an option for all years.

The present engine configuration began with the 1980 models. Changing the emission control system to the oxygen sensor system and an additional raise in the compression ratio has lifted engine performance into the 120 hp range. Removal of pumps, valves and other emission control components has had the additional result of improved gas mileage figures.
 

A new 5-speed transmission accompanies the changes above and the automatic transmission remains an option.

Another addition for the 1980 model year was the Turbo model. Using an exhaust-driven turbocharger, the Turbo's engine produ- ces 150 hp.

Specifications for the European version of the 924 have remained nearly unchanged for the entire run of production. The engine produces 125 hp and is connected to a 4-speed, 5-speed, or optional automatic gearbox.

There has been much speculation on the future of the 924 line. It has been rumored that the car will sport an Audi 5-cylinder, a yet-unnamed V-6, or some other exotic motor for the next update of the 924. Porsche states it is deeply committed to production of the successful design described in this manual and production of the present model, and the ongoing improvements typical of Porsche will continue indefinitely.

Buying spare parts
Replacement parts are available from many sources, which generally fall into one of two categories - authorized dealer parts departments and independent retail auto parts stores. Our advice concerning these parts is as follows:
 

Retail auto parts stores: Good auto parts stores will stock frequently needed components which wear out relatively fast, such as clutch compo- nents, exhaust systems, brake parts, tune-up parts, etc. These stores of- ten supply new or reconditioned parts on an exchange basis, which can save a considerable amount of money. Discount auto parts stores are of- ten very good places to buy materials and parts needed for general vehicle maintenance such as oil, grease, filters, spark plugs, belts, touch-up paint, bulbs, etc. They also usually selltools and general accessories, have convenient hours, charge lower prices and can often be found not far from home.

Authorized dealer parts deparfmenf: This is the best source for parts which are unique to the vehicle and not generally available elsewhere (such as major engine parts, transmission parts, trim pieces, etc.).

Warranty information: If the vehicle is still covered under warranty, be sure that any replacement parts purchased - regardless of the source - do not invalidate the warranty!

To be sure of obtaining the correct parts, have engine and chassis numbers available and, if possible, take the old parts along for positive identification.

Vehicle identification numbers

It is essential that you properly identify your vehicle when pur- chasing spare parts so that you get the right parts for the job you intend doing. Thus far there have been five different engines, four different transmissions, and two different rear suspension designs for the 924 in the US market alone and those do not include any of the many detail modifications.

The Vehicle Identification plate is located on the left hand windshield pillar and can be read from the outside of the car, through the windshield. The Vehicle Identification Number can also be found on a plate inside the engine compartment, adjacent to the battery.

The Chassis Number is stamped on the upper right hand MacPherson strut housing.

The Engine Identification Number is stamped into the engine, just to the left of the crankcase. It is adjacent to the clutch housing.

To find out the color and type of paint used on the vehicle, the Paint Number appears inside the engine compartment for 1979 and 1960 models. For models through 1978, the paint plaque can be found on the doorpost.
 

A Safety Compliance sticker is required for all vehicles sold in the USA. It is located on the rear door jam of the driver's door. It contains the manufacturing date (month and year), Gross Vehicle Weight Rating (GVWR) and Gross Axle Weight Rating (GAWR).

Tools and working facilities
 

A selection of good tools is a fundamental requirement for anyone comtemplating the maintenance and repairofa motor vehi- cle. For the owner who does not possess any, their purchase will prove a considerable expense, offsetting some of the initial savings made by doing-it-yourself. However, provided that the tools pur- chased are of good quality, they will last for many years and prove an extremely worthwhile investment.

To help the average owner to decide which tools are needed to carry out the various tasks detailed in this manual, we have com- piled three lists of tools under the following headings: Maintenance and minor repair. Repair and overhaul and Special. The newcomer to practical mechanics may wish to start off with the Maintenance and minor repair tool kit and confine himself to the simpler jobs around the vehicle. As his confidence and experience grow, he can undertake more difficult tasks, buying extra tools as, and when, they are needed. In this way, a Maintenance and minor repair tool kit can be built-up into a Repair and overhaul tool kit over a consid- erable period of time without many major cash outlays. The expe- rienced do-it-yourselfer will probably have a tool kit good enough for most repairs and overhaul procedures and will add tools from the Special category when he feels the expense is justified.

Maintenance and minor repair tool kit

The tools given in this list should be considered as a minimum requirement if routine maintenance, servicing and minor repair operations are to be undertaken. We recommend the purchase of combination wrenches (boxed one end, open-ended the other); although more expensive than open-ended ones, they do give the advantages of both types of wrench.

Repair and overhaul tool kit
 

These tools are virtually essential for anyone undertaking any major repairs to a motor vehicle, and are additional to those given in the Maintenance and minor repair list. Included in this list is a com- prehensive set of sockets. Although these are expensive they will be found invaluable as they are so versatile - particularly it various drives are included in the set. We recommend the % in square-drive type, as this can be used with most proprietary torque wrenches with an appropriate adapter. If you cannot afford a socket set, then inexpensive tubular box wrenches are a useful alternative.

The tools in this list will occasionally need to be supplemented by tools from the Special list.

Special tools

The tools in this list are those which are not used regularly, are expensive to buy, or which need to be used in accordance with their manufacturers' instructions. Unless relatively difficult mechanical jobs are undertaken frequently, it will not be economic to buy many of these tools. Where this is the case, you could consider clubbing together with friends (or a motorists club) to make a joint purchase, or borrowing the tools against a deposit from a local garage or tool hire specialist.
 

The following list contains only those tools and instruments freely available to the public, and not those special tools produced by the vehicle manufacturer specifically for its dealer network. You will find occasional references to these manufacturer's special tools in the text of this manual. Generally, an alternative method of doing the job without the vehicle manufacturer's special tool is given. However, sometimes, there is no alternative to using them. Where this is the case and the relevant tool cannot be bought or borrowed you will have to entrust the work to a franchised garage or the ordering ability of a friendly parts man.

• Vale spring compressor (modified for 924 use)
• Piston ring compressor
• Balljoint separator
• Universal hub/bearing puller
• Impact screwdriver
• Inclinometer
• Emission control tester
• Micrometer and/or vernier gauge
• Dial indicator
• Stroboscopic timing light
• Tach/Dwell angle meter
• Electrical multi-meter
• Cylinder compression gauge
• Lifting tackle
• Light with extension lead

Last, but not least, always keep a supply of old newspapers and clean, lint-free rags available, and try to keep any working area as clean as possible.

Buying tools

For practically all tools, catalog department stores are the best source since they will have a very comprehensive range compared with the average garage or accessory shop. Having said that, acces- sory shops ofen offer excellent quality tools at discount prices, so it pays to shop around.

Remember, you do not have to buy the most expensive items on the shelf, but it is always advisable to steer clear of the very cheap tools. There are plenty of good tools around, at reasonable prices, so ask the proprietor or manager of the shop for advice before making a purchase.

Care and maintenance of tools

Having purchased a reasonable tool kit, it is necessary to keep the tools in a clean and serviceable condition. After use, always wipe off any dirt, grease and metal particles using a clean, dry cloth, before putting the toots away. Never leave them lying around after they have been used. Asimple tool rack on the garage or workshop wall, for items such as screwdrivers and pliers, is a good idea. Store all normal wrenches and sockets in a metal box. Any measuring instruments, gauges, meters, etc, must be carefully stored where they cannot be damaged or become rusty.

Take a little care when the tools are used. Hammer heads inev- itably become marked and screwdrivers lose the sharp edge on their blades from time-to-time. A little timely attention with emery cloth, a file, or a sharpening stone will soon restore items like this to a good serviceable finish.
 

Not to be forgotten when discussing tools, is the workshop itself. If anything more than routine maintenance is to be carried out, some form of suitable working area becomes essential.

It is appreciated that many an owner mechanic is forced by circumstance to remove an engine or similar item, without the benefit of a garage or workshop. Having done this, any repairs should always be done in an enclosed garage.

Any dismantling should be done on a clean flat workbench or table at a suitable working height.

Any workbench needs a vice: one with a jaw opening of 4 in (100 mm) is suitable for most jobs. As mentioned previously, some clean dry storage space is also required for tools, as well as the lubricants, cleaning fluids, touch-up paints and so on which soon become necessary.

Another item which may be required, and which has a much more general usage, is an electric drill with a chuck capacity of at least 3/8 in. This, together with a good range of twist drills, is virtu- ally essential for fitting accessories.

Jacking and towing

Jacking - floor jack

The spare tire and the jack are located In The luggage compart- ment beneath the floor mat.

Wedge-shaped Indentations are stamped Irito the left and right running boards beneath the doors. These mark the supporf points for the lack

On tne 924 Turbo models the Jack support points are wedge- shaped, as above, but they are parlially hidden by a cover strip.

Jacking - jack stand and vehicle lift points

When raising a Porsche 924 for installing jack stands, or whe- never placing a 924 on a service lift, the four support points are different from the jackIng points above.

Front : The jack stands or lift pads must be placed on the longitudinal side member behind and inboard ogf wheel.

Rear : Place the jack stands or lift pads on the U-shaped reinforcement brackets just ahead of the rear suspension

Towing

There are towing eyes installed at the front and rear of the 924 's body. Hook or tie two lines to thtst points only, as they are reinforced and able to take the strain of towing.If you attempt to toe the car with rope attached to the front axle, you stand the chance of pulling the sleering gera out of the vehicle as wel as severly bending the front air dam.
 

Engine....................................................... Heavy duty oils of SD or SE specification

Summer: SAE 30 weight
Winter: SAE 20 weight
For continuous operation between -15° and 0°C (0° and 32°F):

SAE 20 W 20 weight
For continuous operation below -15°C (0°F): SAE 10 weight

Transmission

Manual .................................................... Hypoid SAE 80, API Spec. GL4 or MIL-L2105
Automatic................................................. ATF 'Dexron'

Differential (automatic transmissions only) .......................... Hypoid SAE 90, API Spec. GL5 or MIL-L2105 B

Wheel bearings ........................................ Lithium-based multipurpose grease

Brake fluid............................................. dot 3 or 4

Safety first!

Regardless of how enthusiastic you may be about getting on with the job at hand, take the time to ensure that your safety's not jeopard- ized. A moment's lack of attention can result in an accident, as can failure to observe certain simple safety precautions. The possibility of an accident will always exist, and the following points should not be considered a comprehensive list of alt dangers. Rather, they are in- tended to make you aware of the risks and to encourage a safety con- scious approach to alt work you carry out on your vehicle.
 

DON'T rely on a jack when working under the vehicle. Always use ap- proved jackstands to support the weight of the vehicle and place them under the recommended lift or support points. DONT attempt to loosen extremely tight fasteners (i.e. wheel lug nuts) while the vehicle is on a jack — it may fall.

DON'T start the engine without first making sure that the transmission is in Neutral (or Park where applicable) and the parking brake is set.

DON'T remove the radiator cap from a hot cooling system — let it cool or cover it with a cloth and release the pressure gradually.

DON'T attempt to drain the engine oil until you are sure it has cooled to the point that it will not burn you.

DON'T touch any part of the engine or exhaust system until it has cooled sufficiently to avoid burns.

DON'T siphon toxic liquids such as gasoline, antifreeze and brake fluid by mouth, or allow them to remain on your skin. DON'T inhale brake lining dust — it is potentially hazardous (see Asbestos below)

DON'T allow spilled oil or grease to remain on the floor — wipe it up before someone slips on it.

DON'T use loose fitting wrenches or other tools which may slip and cause injury.

DON'T push on wrenches when loosening or tightening nuts or bolts. Always try to pull the wrench toward you. If the situation calls for pushing the wrench away, push with an open hand to avoid scraped knuckles if the wrench should slip.

DON'T attempt to lift a heavy component alone — get someone to help you.

DON'T rush or take unsafe shortcuts to finish a job.

DON'T allow children or animals in or around the vehicle while you are working on it.

DO wear eye protection when using power tools such as a drill, sander, bench grinder, etc. and when working under a vehicle. DO keep loose clothing and long hair welt out of the way of moving parts.

DO make sure that any hoist used has a safe working load rating adequate for the job.

DO get someone to check on you periodically when working alone on a vehicle.

DO carry out work in a logical sequence and make sure that everything is correctly assembled and tightened.

DO keep chemicals and fluids tightly capped and out of the reach of children and pets.

DO remember that your vehicle's safety affects that of yourself and others. If in doubt on any point, get professional advice.
 
 

Certain friction, insulating, sealing, and other products — such as brake linings, brake bands, clutch linings, torque converters, gaskets, etc. — contain asbestos. Extreme care must be taken to avoid inhalation of dust from such products since it is hazardous to health. If indoubt, assume that they do contain asbestos.

Fire

Remember at all times that gasoline is highly flammable. Never smoke or have any kind of open flame around when working on a vehicle. But the risk does not end there. A spark caused by an electrical short

circuit, by two metal surfaces contacting each other, or even by static electricity built up in your body under certain conditions, can ignite gasoline vapors, which in a confined space are highly explosive. Do not, under any circumstances, use gasoline for cleaning parts. Use an approved safety solvent.

Always disconnect the battery ground (-) cable at the battery before working on any part of the fuel system or electrical system. Never risk spilling fuel on a hot engine or exhaust component.

It is strongly recommended that a fire extinguisher suitable for use on fuel and electrical fires be kept handy in the garage or workshop at all times. Never try to extinguish a fuel or electrical fire with water.

Torch (flashlight in the US)

Any reference to a "torch" appearing in this manual should always be taken to mean a hand-held, battery-operated electric light or flash- light. It DOES NOT mean a welding or propane torch or blowtorch.

Fumes

Certain fumes are highly toxic and can quickly cause unconscious- ness and even death if inhaled to any extent. Gasoline vapor falls into this category, as do the vapors from some cleaning solvents. Any drain- ing or pouring of such volatile fluids should be done in a well ventilated area.

When using cleaning fluids and solvents, read the instructions on the container carefully. Never use materials from unmarked containers.

Never run the engine in an enclosed space, such as a garage. Exhaust fumes contain carbon monoxide, which is extremely poisonous. If you need to run the engine, always do so in the open air, or at least have the rear of the vehicle outside the work area.

If you are fortunate enough to have the use of an inspection pit, never drain or pour gasoline and never run the engine while the vehicle is over the pit. The fumes, being heavier than air, will concentrate in the pit with possibly lethal results.
 

Never create a spark or allow a bare light bulb near a battery. They normally give off a certain amount of hydrogen gas, which is highly explosive.

Always disconnect the battery ground (-) cable at the battery before working on the fuel or electrical systems.

If possible, loosen the filler caps or cover when charging the battery from an external source (this does not apply to sealed or maintenance- free batteries). Do not charge at an excessive rate or the battery may burst.

Take care when adding water to a non maintenance-free battery and when carrying a battery. The electrolyte, even when diluted, is very corrosive and should not be allowed to contact clothing or skin.

Always wear eye protection when cleaning the battery to prevent the caustic deposits from entering your eyes.

Mains electricity (household current in the US)

When using an electric power tool, inspection light, etc., which operates on household current, always make sure that the tool is cor- rectly connected to its plug and that, where necessary, it is properly grounded. Do not use such items in damp conditions and, again, do not create a spark or. apply excessive heat in the vicinity of fuel or fuel vapor.

Secondary ignition system voltage

A severe electric shock can result from touching certain parts of the ignition system (such as the spark plug wires) when the engine is run- ning or being cranked, particularly if components are damp or the insula- tion is defective. In the case of an electronic ignition system, the secon- dary system voltage is much higher and could prove fatal.

Routine maintenance

The following pages detail the maintenance procedures which will help you keep your Porsche 924 in proper working order. There are a number of common sense tasks which should be performed on a regular basis. These are detailed immediately below. Perform these tasks as noted but do not avoid doing them at the required interval checks. The interval maintenance will give you a clear pic- ture of your vehicle's overall condition and the tasks which must be performed to bring it back to peak operating condition.
 

Required after the first 1000 mile* (1500 km)
1 Change the engine oil (Chapter 1).
2 Replace the engine oil filter (Chapter 1).
3 Check and adjust the valve clearances and replace the valve cover gasket (Chapter 1).
4 Check the cylinder head bolts for proper torque (Chapter 1).
5 Inspect the coolant system. Check coolant level and coolant hoses for tightness and condition (Chapter 2).
6 Check all V-belts for condition and adjust them as necessary.
7 Make a visual check of the fuel tank, fuel lines, connections, and components of the EEC system (Chapter 3). 6 Make a visual check of the exhaust system for signs of damage. 9 Check and adjust the engine idle and the CO level in the exhaust gases (Chapter 3).
 

Required every 7500 miles (12,000 km)
1 Change the engine oil (Chapter 1).

Required every 15,000 miles (24,000 km)
1 Change the engine oil (Chapter 1).
2 Replace the engine oil filter (Chapter 1).
3 Check and adjust valve clearances and replace the valve cover gasket (Chapter 1).
4 Inspect the coolant system. Check coolant level and coolant hoses for tightness and condition (Chapter 2).
5 Check all V-belts for condition and adjust them as necessary.
6 Replace the spark plugs (Chapter 5).
7 Check the timing of the ignition and adjust the timing with the proper electronic equipment (Chapter 5).
8 Make a visual inspection of the ignition wires, the distributor cap, and the ignition rotor and replace components as necessary (Chapter 5).
9 Replace the fuel filter (Chapter 3).
10 Make a visual check of the fuel tank, fuel lines, connections, and components of the EEC system (Chapter 3).
11 Make a visual inspection of the exhaust system for signs of damage and rusting (Chapter 3).
12 Check and adjust the engine idle and the CO Ievel in the exhaust gases (Chapter 3).
13 Replace the air cleaner filter element (replace every two years if you drive less than 15,000 miles (24,000 km) every two years).

Required every 30,000 miles (48,000 km). Perform all 15,000 miles (24,000 km) tasks along with the tasks below
1 Check the tightness of the cylinder head bolts (Chapter 1).
2 Make a visual inspection of the crankcase ventilation hoses (Chapter 1).
3 Visually inspect and perform the required checks on the air pump, control valves, air hoses, and manifolds on models with this equipment (Chapter 3).
4 Replace the filter element for the air pump (Chapter 3).
Maintenance intervals for lubrication and general maintenance, 1976 through 1979

Required after the first 1000 miles (1500 km)
1 Manual transmission: Check the oil level in the transmission and top up as necessary (Chapter 7).
2 Automatic transmission: Check the levels of oil in the differen- tial and ATF in the transmission body and top up as necessary (Chapter 7).
3 Check the play of the bearings in the front wheels and adjust as necessary (Chapter 9).
4 Adjust the free play of the clutch and brake pedals.
5 Check the operation of the lights, horn, windshield wipers and the windshield washer.
6 Check the adjustment of your headlights (Chapter 11).
7 Check and correct the pressure in your tires.
 

Required every 30,000 miles (48,000 km)
1 Manual transmission: Drain the transmission oil and fill with fresh oil (Chapter 7),
2 Automatic transmission: Change the oil in the differential and drain and refill the transmission body ATF (Chapter 7).
Maintenance intervals for emission controls, 1980 - on (Oxygen sensor system)

Required after the first 1000 miles (1500 km)
1 Change the engine oil (Chapter 1).
2 Replace the engine oil filter (Chapter 1).
3 Check and adjust valve clearances and replace the valve cover gasket (Chapter 1).
4 Check and adjust the engine idle speed and the CO level in the exhaust gases (Chapter 5).

Required every 7500 miles (12,000 km) 1 Change the engine oil (Chapter 1).
 

Required every 30,000 miles (48,000 km)
1 Change the engine oil (Chapter 1).
2 Replace the engine oil filter (Chapter 1).
3 Check and adjust valve clearances and replace the valve cover gasket (Chapter 1).
4 Check the V-belts and the timing belt. Replace belts as neces- sary and adjust the others as required. New belts must be read- justed after the first 1000 miles (1500 km) of use.
5 Replace the spark plugs. If you drive less than 30,000 miles (48,000 km) in two years, replace spark plugs at two year intervals, as a minimum replacement figure (Chapter 5).
6 Replace the air cleaner filter element (Chapter 1).
7 Reset the oxygen sensor mileage counter and replace the oxy- gen sensor unit (Chapter 3).
Maintenance intervals for lubrication and general maintenance, 1980 - on (all models including Turbo)

Required after the first 1000 miles (1500 km)
1 Check the coolant level and inspect the hoses for tightness and condition (Chapter 2).
2 Manual transmission: Check the oil level in the transmission and top up as necessary (Chapter 7).
3 Automatic transmission: Check the oil level in the differential and the ATF level in the transmission body. Top up as necessary (Chapter 7).
4 Check the play in the front wheel bearings and adjust as neces- sary (Chapter 9).
5 Adjust the free play in the clutch and brake pedals.
6 Check the operation of the lights, horn, windshield wipers, and windshield washers.
7 Check the adjustment of the headlights and correct as neces- sary (Chapter 12).
8 Check the air pressure in the tires.
9 Make a road test check of the clutch, brakes, steering, heating, and ventilation systems. Correct problems as necessary.
10 Check the performance of all instruments, control, and warning lights during your driving check.
 

Troubleshooting

This section provides an easy reference guide to the more com- mon faults which may occur in the operation of your Porsche 924. These faults and their most probable causes are grouped according to their respective systems, and are further cross referenced to the Chapter which deals with the problems.

Troubleshooting is a practice which requires only a little bit of logic and a basic understanding of what you are dealing with. A systematic approach to the problem at hand will save many hours of random searching and, possibly, a costly visit to a mechanic who is only going to employ the methods above and charge you well for the service.

Logic is a bit more than checking a system part by part. Begin any engine problem by thinking about what has happened since the car last ran well. Have you used a different brand of gasoline? Have you filled the gas tank recently? Could you have left the lights on overnight? Start with the most simple explanation, a change in nor- mal practices or an error, and work toward the most difficult mechanical possibility.

Finally, take the time to find out why something has gone wrong. The solution to an emply fuel tank is different from a blown fuse, but each has a reason for happening. By understanding the cause of the problem, you can take steps to prevent the same prob- lem from happening again. In the case of a blown fuse, for example, failing to find the cause of the fuses' blowing could result in the replacement of a several-hundred dollar electrical component instead of a twenty-five cent fuse the next time around.

Engine

1 Engine will not turn over or turns slowly
1 Turn the ignition switch to the "ON" position and switch on some of the electrical components such as lights, windshield wip- ers. and the radio. If these fail to function, the most probable cause is a defective or discharged battery. Check the condition of the battery and make sure the terminals are in contact and are clean.
2 If the headlights work normally, turn the ignition key to the "START" position with the headlights switched on. If the lights and the instrument panel lights dim, this indicates that the battery is in a discharged state or that the connections are poor.
3 If the headlights stay bright and the instrument panel lights don't dim when the ignition key is turned, this suggests a fault in the wiring between the ignition switch and the starter motor. Check the ignition wiring diagram which is appropriate to your model in Chap- ter 5, You may test the ignition switch by running a short wire between the power in and power out terminals of the switch. If this causes the engine to start, the ignition switch is faulty.
4 If the ignition switch is not at fault, check the starter solenoid and the starter motor (Chapter 5). If your vehicle has an automatic transmission, lift up the plate which surrounds the selector lever and make sure that the contact points on the switch contact are properly aligned and do not have dirt or other obstructions in the way.
 

3 Engine difficult to start when cold (outside temperature)
1 Check the output of the injectors (Chapter 3). If you can hear the pump operating but do not get good flow, the possible faults are dependent upon outside temperatures. If it is below freezing, the most common fault is ice in the fuel lines. Move the car to a garage and warm the car above freezing and attempt to start it again after an hour or so. Use a fuel system antifreeze additive to prevent further icing.
2 If the outside temperature is above freezing and the engine is difficult to start, see the steps below.

4 Engine difficult to start - cold engine
1 Once you have eliminated lack of fuel and lack of spark as prob- lems, check the operation of the thermo time switch (Chapter 3).
2 If the thermo time switch checks out, check the output of the cold start valve (Chapter 3).
3 If the cold start valve checks out, examine the auxiliary air regu- lator's performance (Chapter 3).
4 Check your ignition timing (Chapter 5).

5 Engine difficult to start - hot engine
1 One you have eliminated lack of fuel and lack of spark as the cause of the problem, follow the elimination steps in the above cold start problem-solving to determine whether these components are working when they shouldn't be.
2 Check the output of the injectors (Chapter 3).
3 If your vehicle is a 1979 model, check the operation of the hot start solenoid (Chapter 3).
4 Check the idle adjustment and make any necessary adjustments (Chapter 3).
5 Check your ignition timing (Chapter 5).
6 Check engine compression (Chapter 1).

6 Poor performance during warm-up
1 Carefully check every join in the components of the fuel system for air leaks.
2 Check the performance of the cold start system components to ensure that they shut off or close at the proper time.
3 Check the continuity of ignition wires and components when cold and again at engine operating temperatures (Chapter 5).
4 Check the output of the injectors (Chapter 3).

7 Engine Idles erratically and stalls
1 Check all components of the fuel system for air leaks (Chapter 3).
2 Check the output of the injectors (Chapter 3).
3 Check for water in the fuel. Drain about one quart of gasoline into a clear glass jar from the fuel line between the fuel tank and damper. Water will appear as a clear layer beneath the gasoline in the jar. If water is found, drain the fuel tank and fill it with fresh fuel from a reputable dealer.
4 Examine the wires of the ignition system for tight connection and the spark plugs for cleanliness and proper gap (Chapter 5).
5 Check the operation of the EGR valve (Chapter 3).
6 If none of the above steps solves the problem, perform a com- pression check on the engine (Chapter 1).
 
 

9 Erratic performance during cruising
1 Check the operation of the fuel pump and the injectors. Use the tests in Chapter 3 to determine whether the fuel pump. accumula- tor, fuel filter, fuel distributor, or injectors may be at fault.
2 Remove the spark plugs and check their condition and gap. The color chart in Chapter 5 will help you to 'read' the type of charge being burned in the cylinders.
3 Check the cold starting system, particularly the cold start valve to see that it is shutting completely off and not operating at all under normal running conditions.
4 Check the vacuum line to the distributor for tight fit and lack of pinching or cuts in the tubing. Perform a test on a distributor test bench (Chapter 5) to determine whether the distributor is advanc- ing properly. Check the operation of the vacuum amplifier.
5 Make sure that the air cleaner element is operating properly, is free of plugging, and is properly installed.

10 Car ”urges while decelerating
1 In cars which have manual transmissions and emission controls installed, check the operation of the decel valve.
2 Check the operation of the EGR valve.
3 On vehicles with automatic transmissions, check the throttle control cable on the transmission,

11 Poor engine braking
1 Check the throttle housing and its components for proper operation.
2 Check the operation of the decel valve, if your car has a manual transmission and emission controls installed (Chapter 3).

Coolant system

12 Overheating
1 Check the coolant level in the expansion tank. If the level is not between the upper and lower lines cast into the sides of the translu- cent tank, prepare a mixture of antifreeze according to the mixing directions in Chapter 2. Do no remove the coolant system pressure cap from the top of the expansion tank until you have reviewed the instructions and warnings in Chapter 2.
2 If the system is losing coolant on a regular basis, carefully inspect all hoses and connections for hose condition and loose or overtightened hoses. See Chapter 2 for the proper check pro- cedures.
3 Check the operation of the electric fan and the thermo switch (Chapter 2).
4 If the engine overheats rapidly, but the lower section of the radiator remains cool, remove and perform the appropriate tests on the thermostats (Chapter 2).
5 Check the spark plugs for evidence of a very lean air/fuel mixture.
6 Check the ignition timing (Chapter 5).
7 If the engine continues to run hot after all of the above tests and checks, drain the coolant system and flush it with a proprietary cleaner. Make sure that the cleaner is suitable for use in alloy engines before using. If calcium deposits or rust and scale are a problem, use distilled water in place of tap water.

13 Coolant too cool
1 Perform an operational check of the thermostat (Chapter 2).

Electrical

14 Battery discharges rapidly
1 Check the alternator drive belt for proper adjustment and condi- tion. Adjust or replace as necessary (Chapter 5).
2 Check the electrolyte level in the battery and top up with dis- tilled water if necessary.
3 Check the lighting circuits for shorting or grounding out (Chap- ter 11).
4 Check the output of the voltage regulator (Chapter 5).
5 Have a competent service center check the alternator output.

15 Wiper motor fails to work
1 Check the operation of the proper fuse and relay and replace as necessary (Chapter 11).
2 Check all connections for tight fit and evidence of any frayed or broken wires.
3 Have a competent service center check the operation of the motor and replace if necessary.

16 Wiper motor works very slowly and draws excess current
1 Check the motor for dirt and grit around the shaft and clean it as necessary (Chapter 11),
2 Check the drive linkage for binding, bent parts, or lack of proper lubrication at the pivot points.
3 Examine the motor for binding, worn bearings, or other signs of abuse or wear. Have a competent service center check the motor and replace as necessary.

17 Wiper motor works slowly but draws little current
1 Have the motor checked out by a competent service center.

16 Wiper motor works but blades remain static
1 Check the linkage and replace if faulty or damaged (Chapter. 11).
2 Check the wiper arm holding nuts for tightness and the splined drive pivots for damage or stripping out.

19 Headlights do not come on
1 Check the headlight sealed beam units for burning or broken filaments.
2 Check the headlight relay (Chapter 11).
3 Check the operation of the headlight switch.
4 Check the wiring for breaks and bad connections.

20 Headlights come on but fade (engine stopped)
1 Recharge the battery and perform checks on the battery charge if the problem persists (Section 14).

21 Headlights give poor Illumination
1 Make sure the lenses are clean.
2 Examine the reflectors for dirt and corrosion, replacing any units which show those signs.
3 Check the adjustment of the headlights and make any necessary corrections (Chapter 11).
4 If the headlight lens is old and the unit has discolored, replace the unit (Chapter 11).
5 Check all electrical connectors for clean, tight fitting.

22 Lights flash on and off, especially over bumps
1 Examine all wiring and connectors for loose connections or breaks. Make sure that the system grounds are properly installed (Chapter 11).

23 Headlights do not raise when they are turned on
1 Check the linkage for binding and lack of lubrication (Chapter 12)
2 Check the operation of the motor.
3 Check the operation of the fuse and relay for the motor.
 

25 Horn does not shut off
1 Remove the pad on the steering wheel and separate the two leads from the horn button (Chapter 11).
2 Check the horn relay for condition and operation.

26 Poor tone in the horn
1 Check all horn wiring for loose connections (Chapter 11).
2 Disconnect each horn in turn to determine which horn is bad. Replace that horn.

27 Fuel level gauge reads 'maximum' continuously
1 Remove the fuel tank sending unit and test (Chapter 3).
2 Remove the gauge and test.
3 Check all wiring for defects.

28 Fuel level gauge gives no reading
1 Check all wiring in this system for proper connectors and proper grounding (Chapter 11).

29 No reading on tachometer
1 Have the tachometer and transistorized ignition control unit tested by a qualified mechanic.
 

Clutch

31 Clutch judders when engaged
1 Check the condition of the bonded mounts for the engine, drive- line tube, and the transmission (Chapters 1 and 7). Tighten or replace mounts as necessary. On 1978 and later models, check the condition of the engine shock absorber beneath the engine.
2 Examine the clutch lining for thickness. If there is useable lining material shown, remove the clutch disc and pressure plate and inspect these components according to the instructions in Chapter 6. Correct any oil leaks which might be causing problems and replace clutch components as necessary,
3 With the clutch disc and pressure plate removed, check the con- dition of the pilot bearing in the center of the flywheel and correct any problem as necessary.
4 Inspect the drive shaft and drive shaft dampers for proper instal- lation and condition.

32 Clutch drags or does not allow gears to engage
1 Check the adjustment of the clutch cable (standard models) and make any necessary corrections (Chapter 6),
2 If the car has sat idle for some time, the clutch friction plate may be seized on the splined shaft. This is the result of a small amount of rust or corrosion holding the plate on the shaft. It is not a major problem and will go away with increased use of the car. To free the clutch disc from the shaft, engage the transmission in top gear, engage the parking brake and depress the clutch pedal. Engage the starter and allow the engine to turn over. If the clutch disc is badly seized, the engine will not turn. This solution is a temporary mea- sure and the clutch disc and pressure plate should be removed and inspected (Chapter 6), as well as inspecting the splined shaft and cleaning the splines with a wire brush.
3 If the above solution does not free the clutch disc, it will be necessary to remove the clutch disc and pressure plate. Inspect all parts carefully and replace parts as necessary.

33 Clutch slips
1 Check the adjustment of the clutch operating cable and make any corrective adjustments required (Chapter 6).
2 Inspect the clutch disc friction lining thickness (Chapter 6).
3 Remove the clutch disc and pressure plate and look for signs of oil leaks, hard spots, and other evidence of abuse or wear (Chapter 6).
 

34 Transmission balks on downshifts, gear shifts slow
1 Synchromesh bodies are worn or do not have proper clearances after reassembly. The transmission will have to be stripped down and repaired (Chapter 7).

35 Gears jump out of mesh
1 The shift forks are worn or out of adjustment; the grooves in the selector rod are worn; or there is excessive end float at the end of the gear shafts. In any case, the transmission must be stripped down and inspected for the appropriate repairs to be made (Chap- ter 7).

36 Excessive transmission noise
1 Check the oil level and top up as required.
2 If the noise persists, the cause is most likely worn parts in the transmission. Strip the transmission and inspect all parts for the appropriate repairs to be made (Chapter 7).

37 Difficulty in engaging gears
1 Check the adjustment of the clutch (Chapter 6).
2 Check the adjustment of the shift linkage. Inspect all pivoting and rubbing components for binding and bending.
3 If the above adjustments do not solve the problem, the correc- tion to this matter lies in the condition of internal transmission parts. Strip the transmission and inspect all parts for the approp- riate repairs to be made (Chapter 7).

Automatic transmission
 

39 Erratic drive performance
1 In all forward gears: ATF level too low (Chapter 7).

40 Erratic shifts when engaging D or R from N
1 Idle speed set too high (Chapter 3).
2 ATF level too low (Chapter 7).

41 Upshift too long from 1 to 2
1 ATF level too low (Chapter 7).

42 Upshift too long from 2 to 3
1 ATF level too low (Chapter 7).

43 Kickdown malfunctions

1 Control pressure cable out of adjustment (Chapter 7).

44 Poor acceleration
1 Ignition, fuel supply, or compression problems (Chapters 1, 3, 5).
2 Throttle cable out of adjustment (Chapter 3).
3 Control pressure cable out of adjustment (Chapter 7).
 

46 Excessive vibration
1 Check all of the mounts of the engine, drive shaft housing, and transmission for tightness. Make any necessary corrections (Chap- ters 1 and 7).
2 Remove the drive shaft and have it checked for balance and distortion (Chapter 7). This requires a dynamic balance test.
3 Examine the rear wheel bearings and the axle shafts for tight- ness and alignment (Chapter 10).

47 Knock or 'clunk' when taking up drive or changing gear
1 Check the mounts of the engine, drive shaft housing, and trans- mission for tightness (Chapters 1 and 7). Make any necessary corrections.
2 Check the tightness of the gears in the planetary gear set in the final drive (Chapter 7).
3 Twist the axle shafts back and forth to check for wear in the axle shaft splines.

48 Rear axle noisy on turns 1 Check the planetary gearbox for wear (Chapter 7).

49 Rear axle nolsy under all conditions
1 Check the ring and pinion gears for proper adjustment and the planetary gear set in the differential for wear. This will require re- moving and stripping the transmission (Chapter 7).

Brakes

50 Brake pedal travels almost to the floor before the brakes operate
1 Check the fluid level in the master cylinder reservoir and top up as required (Chapter 9).
2 Check the brake pads (front) and the brake linings (rear) for wear and replace if necessary (Chapter 9).
3 Make a visual inspection of the brake linings and hoses for frac- tures or leaks. Tighten connections to proper torque specifications or replace damaged parts as required.
4 Check the operation of the master cylinder and the brake boost- er and replace or rebuild parts as required (Chapter 9).
 

52 Brake pedal feels spongy and soggy
1 Bleed the system to remove any possible air in the hydraulic lines. If the brake fluid is over two years old, drain the entire braking system and fill it with new hydraulic fluid from a previously- unopened can (Chapter 9).
2 Examine the calipers, fittings, lines and hoses of the braking system for leakage, loose connections, broken or punctured hoses, or worn seals. Replace parts and rebuild calipers as necessary. Remember to rebuild front brake calipers and/or wheel cylinders as a set on an axle (all front or rear at once) (Chapter 9).
3 Check for leaks in the master cylinder by looking for air bubbles in the brake fluid reservoir. Rebuild the master cylinder as neces- sary (Chapter 9).

53 Excessive brake pedal pressure is required to slow car
1 Check the brake pads and brake shoe linings for glazing. This problem is usually caused by improper breaking-in or repeated hard stops. The glaze can usually be broken by sanding the surface slightly with fine sandpaper. Do not breathe the dust from this procedure,
2 Check the brake booster unit. including the vacuum lines and the check valve for proper operation (Chapter 9).
3 If neither of these checks provides a solution, the problem may be one of the material on new brake pads being of a harder material than the old ones; contamination of the friction surfaces by grease, oil or brake fluid; or pads in need of replacement.

54 Brakes pulling to one side
1 This is an unusual problem with the 924, as the negative scrub radius characteristics of the suspension and the diagonal braking circuits should prevent such an occurrence. The first check, there- fore, is to make sure that the brake lines and hoses are not broken, plugged, or leaking.
2 If the problem persists, have the alignment of the car checked by a competent service facility.

55 Brakes bind, drag, or lock
1 Check the adjustment of the rear brake shoes and slacken the adjusting nuts if necessary (Chapter 9).
2 Check the adjustment of the handbrake (Chapter 9).
3 Examine the master cylinder and brake booster for incorrect operation. Make sure that the check valve in the brake booster vacuum line is installed in the proper direction (Chapter 9),

Steering and suspension
 

57 Steering heavy and stiff
1 Check tire pressures.
2 Check the adjustment of the steering gear tension adjusting bolt on the pinion cover plate. Adjust as required (Chapter 8).
3 Have the toe-in of the front suspension checked and adjusted by a competent service facility.

58 Wheel wobble and vibration
1 Check the wheels for bent rims, and the tires to make sure they have no bulges or other obvious out-of-round conditions.
2 Check that the wheel nuts are correctly tightened in a cross pattern and torqued to the proper setting (Specifications, Chapter 9).
3 Check the balance of the wheels. This can be done quickly by a tire store or similar shop.
4 Check the free play in the ball joints (Chapter 10).
5 Check the front wheel bearing's adjustment (Chapter 10).

59 General suspension and steering rattle
1 Check all steering gear mounting bolts for tightness (Chapter 8).
2 Check all bushings in the front suspension for wear and separa- tion of the metal pieces from the rubber bushes (Chapter 10).
3 Check the adjustment of the steering gear tension adjusting bolt on the pinion cover plate. Adjust as required (Chapter 8).
4 Check that the two steering column bearings are not worn out, by grasping the center of the steering column beneath the dash- board and trying to shake the steering column up and down.
5 Examine all suspension mounts for wear in the bushings or loose fittings (Chapter 10).