Typical faults
Harnesses, Pentosin, door boots, Hall sensors, Bose fiber. Filter with the garage and the list shrinks to your car.
On 1990–1995 M104, M119 and M120 cars the loom insulation turns to green dust. Misfires, no-starts and ghost codes follow.
Eleven or twelve rams, one pump, and Pentosin everywhere. The most expensive ‘character’ of the R129 if you ignore the first drip.
Central locking is vacuum. The door-boot tubes rot, the pump runs all night, the battery dies, and then the radio is ‘broken’ too.
A window that has forgotten where it is will also halt the roof. Battery work is the usual trigger.
Fuse 9 (8 A), lid-card A (Radio) and C (Soundsystem), trunk battery, Bose amp, fiber ring on late cars. In that order. Not fuse B — B is the A/C clutch.
Adaptive damping was standard on many V12s and optional elsewhere. Accumulators and valve blocks age; the car does not become a tractor overnight without a reason.
A blank CBU, a blower that only works on 4, or flaps that sneeze behind the dash.
Series I lamps cook their own looms. Series III projectors are happier, until the igniter for the Xenon pack dies.
A safety system that shares hydraulics with the roof. Treat a lean as a cylinder, not as a quirk.
M104 heads, M119 valve covers, M113 oil-cooler seals that impersonate a rear-main leak.