I have a head scratcher! Hoping the community can give me some pointers! I have an X3 E83 2.5i with the m54 engine. Currently my car drives like a slug! Max speed 45 mph and forget going uphill. It does start and tick over fine but when driving it won't rev passed 3.5k revs and takes about 10 mins to reach 40mph. If I try to push it the car limps and I get eml light on. Switch off and on again and the light goes away! I scanned with INPA before the eml comes on and no codes generated. I managed to scan when the car was in limp and I get codes for both cam sensors, the exhaust vanos solenoid, axillary air blocked. Restart the car and codes go away??? Not sure what to change first, any suggestions?

Morning Dave

Welcome to the Forum

The fact that codes are self clearing would indicate they are symptoms not the cause. Check the Mass Airflow Sensor and the Throttle Body I have experienced faulty units with both that didn't throw codes. Your restricted performance would make me think first throttle body or throttle pedal position sender as a starting point.

When you scan are all control units seen or are some not responding? (Greyed out)

Good Luck

Dave

Hi thanks for your reply. The maf sensor has recently been changed. It could be related to the throttle body, I will investigate that😊

 

The fact the MAF was changed doesn't mean it's working (Been there) so I would double check, 1 is it the correct part for the car and 2 that it works.

Throttle body I believe were pretty unchanged from 99 through to 2005/6 they were also used on many other models so check realoem 

Good Luck

Dave