E34 1995 M50 check engine light
Newbie, I have a 1995, 525i white BMW that grew on me. A while ago the check engine light turned on, took it to my local mechanic he could not get the stomp test to work, but told me you can stick a black tape on the light and forget it, engine is working fine. I took it to another dedicated more expensive German car mechanics, his diagnostics pointed to the MAF sensor, it would cost around a grand to get it replaced, first time to here about the MAF sensor but did my research thanks to the forum. I ordered an new OEM MAF sensor from ebay, changed it myself light turned off for a couple of hours then the check engine light turned on again. I took it back to the original mechanic he replaced the OEM with the original Bosch one and told me the OEM won't work with the system and the car is fine and ignore the red light, he also mentioned that the stomp test pointed to the Oxygen Sensor which I replaced twice in 2 years time. I did most of the tests that I found on this forum and others, including vacuum test where I sprayed a carb. started fluid all around the vacuum lines and diidn't notice any extra engine acceleration, I also did the internal cylinder combustion cleaning procedure. I know it is not the oxygen sensor because the check engine light turns on as soon as the engine starts (read it somewhere here before). Currently the car runs really rough with the MAF sensor harness connected, if I disconnect the MAF sensor's electric harness the car runs better but the engine RPM fluctuates sometimes stall at low RPM.
Any idea what I can do to find the problem. Appreciate all the help.
Thanks in advance