Models · BMW
BMW Z3 M Roadster and M Coupé buying guide
The M versions of the Z3, built from 1997 to 2002 as the M Roadster and the fixed-roof M Coupé. Cars built up to mid-2000 have the S50 3.2 straight-six from the E36 M3 Evolution, and later cars the S54 from the E46 M3, both with a five-speed manual.
The versions
- S50 3.2 straight-six, 321PS (1997 to 2000)
- S54 3.2 straight-six, 325PS (2001 to 2002), with drive-by-wire throttle and DSC
- M Roadster with an electric fabric hood, and the M Coupé hatchback
- Five-speed manual only, with a limited-slip differential
- Characters four and five of the chassis number show the version: CK and CL are Roadsters (S50 and S54), CM and CN are Coupés (S50 and S54)
What to check on a Z3 M
3 model-specific things to look at when you view one. They're a starting point, not the full inspection.
Cracks in the boot floor
What to look for: Empty the boot, lift the carpet and any sound deadening, and with a torch follow the floor seams and welds, especially on the left-hand side and towards the middle. Look for cracked paint along a weld line, a crack in the metal or a seam that has opened. Then look at the same area from underneath.
Why it matters: The differential is held at the boot floor by a single mounting on the left, and the spot welds around it can fatigue and crack, worse with hard driving. It affects both bodies and both engines. Welding the crack alone isn't a lasting fix; the accepted repair is a reinforcement kit welded in, and a documented one adds to a car's value.
A rattle from the front of the engine
What to look for: With the bonnet open and the engine cold, start it and listen at the front. It should idle high for a minute or so, then settle with an even, light tick from the valve gear. A rattle or diesel-like clatter from the front, a lumpy idle or a loud tick that doesn't fade are the things to note.
Why it matters: A front-end rattle usually points at the VANOS variable camshaft timing unit, whose seals harden with age on every car eventually, or less often a worn timing chain guide. A tick that stays loud suggests the valve clearances need adjusting. A VANOS rebuild on record is a good sign.
Pull from low revs
What to look for: Once the oil is warm (the oil temperature gauge at about 80°C or more), accelerate in third gear from about 2,000rpm. The engine should pull strongly and evenly, getting harder as the revs rise, with no flat spot or hesitation around 3,000rpm.
Why it matters: VANOS varies the timing of both camshafts to give low-speed torque. On the S50 its seals harden with age, causing lost torque below about 3,000rpm, a flat spot around 3,000rpm and a lumpy idle. A diagnostic read and VANOS test by a specialist confirms it.
Also in the full guide
- Cooling system plastics
- Valve clearances and the service record
- S54 cars: connecting rod bearings
- The secondary air pump
- The cold start, test drive and paperwork checks for the exact version you're viewing
The full guide to the Z3 M
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 BMW.