Porsche 924S: Buyer’s Guide

Common Issues by Area & What to Check Before You Buy

The Porsche 924S is one of the most underrated transaxle Porsches. With its 1980s styling, excellent weight balance, and genuine Porsche engineering, it offers a rewarding driving experience at a relatively accessible price point. However, like any classic Porsche, age and maintenance history matter far more than mileage.

This buyer’s guide breaks down the most common Porsche 924S issues by area of the car, helping you understand what to check before buying and where problems can become costly if ignored.

Service History & Maintenance

Service history is critical on a 924S.

• Many cars have exceeded 100,000 miles, often more than once around the clock

• Mileage is far less important than evidence of consistent maintenance

• Look for invoices confirming major work, not just service stamps

Poorly maintained examples can quickly cost more to put right than the car is worth.

Engine & Engine Bay

The 924S uses the 2.5-litre Porsche engine, shared with the 944, and is generally robust when maintained correctly.

Timing Belt, Balance Belts & Water Pump

One of the most important areas to check.

• Timing belt and balance belts must be replaced at correct intervals

• Water pump should be replaced at the same time

• Failure can result in catastrophic engine damage

A recent belt and water pump change is a major positive.

Oil Leaks

Very common on ageing engines.

• Cam cover gasket

• Front and rear crank seals

• Sump gasket

Minor leaks are normal, but heavy oil loss suggests overdue maintenance.

Valve Spring Failure

An often-overlooked age-related issue.

• Valve springs can snap due to age

• Causes intermittent misfires, especially at low RPM

• Can be difficult to diagnose without experience

If a car has unexplained running issues, this should be considered.

Cooling System

Cooling systems are a known weak point on older 924S models.

Hoses & Pipes

• Original hoses become brittle and crack with age

• Look for signs of coolant leaks or staining

Radiator

• Original radiators corrode internally

• Leaks and overheating are common

• Alloy replacement radiators are a popular and effective upgrade

Cooling Fans & Thermostat

• Fan failure is common and can cause rapid overheating in traffic

• Thermostat issues can lead to incorrect operating temperatures

Always ensure the fans cut in correctly once warm.

Suspension, Steering & Wheel Bearings

Wheel Bearings

A critical but often misunderstood area.

• A very slight amount of play is required

• Bearings set too tight will overheat and fail

• Incorrect adjustment is common after DIY work

Suspension Bushes & Joints

• Original rubber bushes are usually worn out

• Causes vague steering and knocking noises

• Polyurethane bushes (e.g. Powerflex) are a positive upgrade

Steering Rack & Linkages

• Check for play, stiffness, or knocking

• Age and lack of use can cause stiffness and wear

Rear Torsion Bars

• Rear of the car sitting low can indicate torsion bar sag

• A known issue on ageing cars

• Rectification can be labour-intensive

Shock Absorbers

• Worn shocks cause wallowing and uneven tyre wear

• Knocking noises at low speed are a common symptom

Brakes

• Generally simple and reliable

• Parts are affordable

• Check discs for heavy lips and pads for remaining material

Lack of use can cause corrosion-related issues.

Fuel System

Many 924S cars spent long periods unused, leading to fuel system problems.

Fuel Tank

• Original metal tanks can corrode internally

• Rust contamination causes injector and running issues

• Plastic 944 fuel tanks are a common retrofit solution

Fuel Pumps & Lines

• External fuel pumps can corrode and leak

• Look for signs of wetness or staining

• Severe corrosion can lead to pump failure

Gearbox, Clutch & Drivetrain

The 924S uses a rear-mounted transaxle gearbox, contributing to its excellent balance.

Clutch

• Clutch replacement is labour-intensive

• Torque tube must be removed

• A recent clutch is a significant advantage

Symptoms of wear include:

• Slipping

• Shuddering on take-off

• High or inconsistent bite point

Gearbox

• Generally very strong (Audi-derived unit)

• Synchro wear most noticeable in second gear and reverse

• Check for grinding or resistance when cold

Gear Linkages

• Can become stiff or sloppy with age

• Lack of use accelerates wear

• Should feel positive and self-centre correctly

Exhaust System

• Original systems corrode with age

• Rear silencers are a common failure point

• Easy to inspect visually from the rear

Aftermarket systems are common but should be checked for noise and condition.

Bodywork & Corrosion

The 924S has reasonable factory corrosion protection, but rust is still a concern.

Battery Tray

• Acid leaks damage paint and metal

• Can rot through if neglected

• Easy to inspect and often overlooked

Spare Wheel Well & Rear Arches

• Common rust area

• Lift carpet and inspect carefully

• Look for moisture, bubbling, or previous repairs

Windscreen Seals

• Water traps cause corrosion around the frame

• Look for bubbling or blistering at the edges

General Bodywork

• Check for filler using a magnet

• Look for uneven panel gaps or overspray

• Accident repairs are not uncommon

Interior & Electrical Systems

Dashboard Cracking

• Extremely common on 924S and 944 models

• Caused by UV exposure

• Repair or replacement is expensive and difficult

Condition varies, but fewer cracks is always preferable.

Seats & Trim

• Seat bolsters wear with age

• Leather and cloth interiors both suffer

• Replacement trim is increasingly hard to source

Electrical Systems

Check everything.

• Windows

• Heater controls

• Gauges

• Interior lights

• Horn and wipers

Electrical faults are usually age-related rather than design flaws.

Sunroof & Rear Hatch

• Large seals commonly leak

• Check operation and water tightness

• Rear hatch glass and seals are known leak points

Pop-Up Headlights

• Mechanisms can fail

• Parts availability is becoming limited

• Ensure smooth operation

Aftermarket Wiring

• Many cars have aftermarket stereos

• Check for poor wiring, bodged connections, or exposed cables

• Electrical fires are a real risk on badly modified cars

Road Test Checks

A road test will reveal many hidden issues.

• Engine should start easily and idle smoothly

• No excessive smoke once warm

• Should feel light, nimble, and responsive

• Watch for overheating or misfires under load

• Listen for:

  • Clicking on full lock (CV joints)

  • Steering vibrations (wheel bearings, CVs, buckled wheels)

A healthy 924S should feel tight and balanced, not vague or tired.

Final Buying Advice

A good Porsche 924S is a genuine hidden gem, but buying the wrong one can quickly become uneconomical.

Key takeaways:

• Condition and history matter more than price

• Deferred maintenance adds up fast

• Cooling, belts, and fuel system condition are critical

• Always budget for age-related repairs

Buy a well-maintained example, and the 924S delivers one of the best-balanced and most enjoyable classic Porsche driving experiences available. Thinking of buying? We can help so be sure to get in touch! Info@sportsvehicleperformance.co.uk01386 793138