Thats a warp on the E38

Back to its Best — BMW Gearbox, Fuel & Sensor Overhaul

This one came in running rough and leaving puddles. The owner had been putting up with a sluggish gearbox, noticeable power loss, a fuel leak, and a fuel gauge that had given up entirely. Not a fun combination.

Diagnosis

First things first — we put it on the diagnostic suite and had a proper look. What came back was a faulty camshaft position sensor alongside two failing O2 sensors. These were quietly wreaking havoc on fuelling, timing,
and power delivery. On top of that, a vacuum leak was making everything feel worse than it needed to be.

Getting it driving again

New camshaft sensor, both O2 sensors replaced, and the vacuum leak sealed. The difference was immediate — power came back, the gearbox stopped hunting, and the rough idle smoothed right out. These are the kinds of faults
that can make a good car feel completely broken, and it's always satisfying to see them sorted properly.

The fuel side

With driveability sorted, we turned our attention to the fuel issues. The leak and the dead gauge are well-documented on these cars — a known weakness in the tank setup. We sealed the tank and repaired the fuel level
signal, bringing the gauge back to life and putting an end to the leak for good.

The car left in a completely different state to how it arrived. Night and day.