What goes wrong, what it costs, and what to check before you buy a used Porsche 928.
The Porsche 928 occupies a niche position on the UK market.
We track 5 known issues across the Porsche 928 range, including 2 rated as safety-critical. Knowing which variants and configurations to approach with caution can save you from expensive surprises after purchase.
Found a Porsche 928? Enter the reg to see which of our 5 known issues apply to that exact car, plus full MOT history and mileage checks.
928 (1987–1995) — Engine options included the 5.0L V8. Our database flags 5 known issues on this generation, 2 of which are rated as safety-critical. The most significant concern is Brake hose corrosion and ferrule failure (£150–£300 to address).
MOT data shows 928s fail brake hose ferrule corrosion tests at 4.9 times the national average. The ferrules (metal crimped ends of flexible brake hoses) corrode due to the car's age and exposure to road salt. When ferrules fail, brake fluid pressure is lost and the brakes become ineffective. This is a critical safety issue.
Failed brake hoses can cause complete brake failure resulting in serious accident. The car should not be driven if brake hose integrity is compromised. Replacement requires specialist brake system knowledge and proper bleeding procedures.
Check brake disc condition for lipping or scoring. Test braking at moderate speed for pulling to one side or vibration through the steering wheel. Review MOT advisories for brake-related items.
The 928 uses an interference V8 engine where timing belt failure causes catastrophic valve and piston damage. The rubber timing belt deteriorates with age and mileage, and failure without warning is documented across all 928 variants. Due to the car's age, many have exceeded recommended replacement intervals multiple times.
Timing belt failure destroys the engine requiring complete rebuild or replacement. Repair costs typically exceed the car's value. The 928's complex V8 design makes timing belt work expensive even as preventive maintenance.
Listen carefully for a rattle or ticking noise from the engine on cold start — this is the most common early sign. Ask for evidence of chain replacement in the service history. On higher-mileage cars without documented replacement, budget for preventative work.
MOT data shows 928s fail wheel bearing tests at 9 times the national fleet average, particularly on high-mileage cars. The combination of the car's weight, age, and performance driving history puts exceptional stress on the bearings. Failure typically occurs on the rear axle first due to the transaxle configuration placing more weight over the rear wheels.
A failed wheel bearing can cause wheel collapse and complete loss of control. Replacement requires specialist tools and knowledge of the transaxle configuration. Costs are high due to the complexity of accessing rear bearings.
Listen for knocking, clunking or rattling over bumps during the test drive. Inspect the underside for corroded or cracked suspension components. Check the MOT history for suspension-related advisories, which often predict future failures.
MOT data shows 928s fail environmental fluid leak tests at 8 times the national average. The V8 engine and automatic transmission develop multiple leak points as seals age. Common sources include the rear main seal, transmission oil cooler lines, and automatic transmission case. These cars were designed when oil consumption and minor leaks were considered normal.
Excessive leaks can pose environmental hazards and safety risks to other drivers. Major leaks can lead to low fluid levels causing engine or transmission damage. The 928's complex layout makes leak diagnosis and repair time-consuming and expensive.
Check the oil level before the engine is started. Ask the seller how often they top up the oil between services. After a test drive, check the level again and look behind the car for blue or grey exhaust smoke under acceleration.
MOT data shows 928s fail CV joint boot tests at 3.7 times the national average. The rubber boots protecting the constant velocity joints crack and split with age, allowing dirt and water to contaminate the joint grease. The 928's rear-mounted transaxle configuration means the driveshafts are longer and work at greater angles than conventional layouts.
Failed boots allow contamination of CV joints leading to expensive joint replacement. If caught early, boot replacement prevents joint damage. Delayed repair typically requires complete driveshaft replacement due to joint wear.
Listen for clunking or vibration from underneath when pulling away or changing direction. Check for play in the driveshafts by rocking the car in gear with the handbrake on. Worn CV boots are a telltale sign — look for grease splatter around the inner wheel arch.
For the full breakdown of all 5 tracked issues with repair costs, see the Porsche 928 common problems page.
Routine servicing (oil and filter change every 6k miles) typically costs £80–£120 at an independent garage.
The bigger-ticket items to budget for include timing belt and tensioner (£800–£1,200), automatic transmission fluid (£200–£350).
See the full Porsche 928 service schedule for every interval and cost breakdown.
The Porsche 928 has some well-documented weak points, including 2 safety-critical issues that demand careful checking. The right example, properly maintained, can still be a sound purchase — but cutting corners on the pre-purchase inspection is not advisable.
Before committing, check the car's full MOT history, verify the service record is complete, and if possible arrange a specialist inspection. Enter any registration into our free report to see the complete picture.
Get Car Wise maintains a database of known mechanical issues for every popular car on UK roads, tracking the faults that owners, specialists and DVSA data reveal.
When you run a report on a specific Porsche 928, we cross-reference the exact variant, engine and age against our database of 5 known issues. Combined with full MOT history analysis, mileage verification and DVLA data, you get a complete picture before viewing.
Enter the registration for MOT history, mileage verification, known faults for that exact variant, and a Get Car Wise Score.
This guide was compiled from independent expert reviews, DVSA MOT data, specialist workshops and our own database of 5 known Porsche 928 issues. We are not affiliated with any source listed.