Models · Porsche
Porsche 928 buying guide
Porsche's front-engined V8 grand tourer, built from 1977 to 1995, growing from the original 4.5 through the 4.7 S and S2 and the 32-valve 5.0 S4 and GT to the 5.4 GTS. Most were automatics, and a well-maintained car is a durable long-distance machine.
The versions
- 928: 4.5 V8, single overhead camshafts, 240PS
- 928 S and S2: 4.7 V8, 300PS (S) and 310PS (S2)
- 928 S4 and GT: 5.0 32-valve V8, 320PS (S4) and 330PS (GT, manual only)
- 928 GTS: 5.4 32-valve V8, 350PS
- 5-speed manual or Mercedes-derived automatic (three-speed on early cars, four-speed later); over 80 per cent were automatics
- Transaxle layout: engine at the front, gearbox at the back, joined by a torque tube
What to check on a 928
3 model-specific things to look at when you view one. They're a starting point, not the full inspection.
Cambelt and water pump history
What to look for: Find the date and mileage of the last cambelt change in the paperwork. It should be within the last four years or 60,000 miles, and the water pump is normally changed with it.
Why it matters: On every engine except the original 4.5, the valves and pistons meet if the belt breaks, so a failure causes serious engine damage. A recent belt change by a specialist who knows these engines is one of the best signs of a car that's been looked after.
The flex plate check on automatics
What to look for: On an automatic, look for paperwork showing the flex plate and crankshaft end float check, done at the torque tube clamp under the car. Specialists recommend it yearly.
Why it matters: If the clamp on the torque tube holds the flex plate under tension, it pushes the crankshaft forward and wears the crankshaft thrust bearing. Caught early, releasing the tension and measuring the end float is a routine job. Specialists treat it as most important on the 32-valve automatics.
Smoke when warm
What to look for: Watch the exhaust after the engine is fully warm, and when the revs are blipped. A puff on a cold start that clears is normal. Blue smoke that carries on when warm is the thing to note.
Why it matters: Persistent smoke points at worn valve guides and possibly bores. Oil use of around 500 miles per litre is normal for these engines. A compression or leak-down test tells you the engine's condition.
Also in the full guide
- Running and idle quality
- Fuses and relays in the passenger footwell
- Automatic gearbox and manual gearchange
- The cold start, test drive and paperwork checks for the exact version you're viewing
The full guide to the 928
The CrankSight guide walks you round the car on your phone at the viewing, with every check for the exact version you're looking at: what to look for, where to find it, and what anything you find is likely to cost. As you go it builds an assessment of that car, and if you view more than one, it lines them up side by side.
£29 for the model, used on as many cars as you like, delivered within 72 hours or your money back.
General points for the model, last checked October 2026. Every car is different, so treat this as a guide to what to look at, not a verdict on any car. CrankSight is independent and has no connection with Porsche.