Hi, I'm just writing as a bit of advice for anyone who has suffered loss of power in their M5x engine in the e36 or e39 . Symptoms were loss of power when warm and power surges on wide open throttle, between 2000-4500 rpm. When cold it ran fine and pulled hard .
I changed the crank sensor and it made a little difference, but not 100% . I then bit the bullet and fitted 2 new NTK o2 sensors and that fixed the issue, runs fine hot or cold. I knew it was a sensor which controlled fuelling because cold it runs on a base map and ignores sensor input. The car has 220,000 miles on it and the lambda sensors were the originals ! Well worth changing its transformed the car, much stronger mid-range.
did you have a check engine for any sensors? i changed my 02 sensors but it still hesitates at 3.5k and whenever its cold it will rev up fine but when warm i will rev it up, the rpm needle will fall more slowly and stop at 1k revs then fall down to normal idle.
A diagnostic scan with a BMW specific scan tool/software, may provide an answer or clue.
Bookmarks