Hi all,

My 1992 500E is suffering from a strange problem. It seems to run fine at lower RPM's but less and less strongly as revs rise, to the point it barely makes the shift point at WOT. following the shift, it feels pretty strong again, then falls off just the same thru the next gear. If I hold the car in first, it struggles like hell to get to redline at WOT. I suspected maybe the fuel filter was the culprit, restricting flow, but I swapped it out to no benefit. My mechanic friend, a master tech for BMW, feels like I should swap the mass air meter, but since I don't have one and it's not a cheap part, I am second-guessing him here. Has anyone experienced this issue? Has anyone had problems with their MAF, is that a common issue on these cars? Mine has 275k miles on it, has had the wiring harness upgrade, and otherwise runs like a top usually, although every once in awhile I will start it up and it will sputter, run roughly, and not want to take any throttle input, but when that happens, usually if I shut it off and re-start it, it clears right up.

Any help would be appreciated!

Brian Flanagan
1992 500E

Have you checked the fault codes? It sounds like the limp home mode - are you getting an ASR light?

I haven't been able to check the fault codes as of yet. I am scared of our local shops, not very trustworthy IMO. My check engine light is inoperable, I haven't pulled the cluster yet to see if the bulb is just bad, but I assume so. No ASR light, no trouble lights of any sort (and obviously no check engine light). It has pretty good power down low, so I was not thinking limp-home... wouldn't it feel weak down low as well?

If the ASR light is working and not on it's not the limp home mode. Next step is to build the code reader and read the fault codes - try a search. You can swap bulbs to see if the CE bulb is bad, or perhaps it's been taken out.

http://www.k6jrf.com/MB_X11.html