Help with 2002 4.6is rough running

[David.X5]

I did have that valve (#8) fail, but it did throw a code. They are not expensive. If it fails open, you get exhaust gas going into the air pump (#1) which will ruin it pretty quickly. I believe the pump should only run the first 60-90 seconds from a cold start, after that, the pump should turn off and the vacuum valve should close. It would take 3-4 hours sitting before the engine cooled enough for the pump to run again on the next start.

If you haven't done them, the little o-rings (#12) go bad, but I think they were part of what is replaced in the Beisan process.

[murf]

Every once in awhile I get this code. When I do it puts the car in Eng Fail safe Mode.

[upallnight]

Either you have a problem with the pedal potentiometer, or the EML is out of whack. Should check to make sure the EML move freely throughout it range.

[murf]

All right guys, I'm back with some followup.

It took me a while to get things sorted out because I had multiple problems going on all at once. I had to walk away many times for weeks on end just to get away from it for a bit.

The engine kept going into ENG SAFE MODE which was a show stopper ever time it did that. Found out I had a bad throttle body that was intermittent. Replaced that and then moved on from there.

The honest bottom line, as some have suggested, I had the timing off and when I realized it I couldn't believe it. I had the 5-8 cam cover off 15-20 times tweaking the timing wheel to get it exact timing with no adaptation (you can see this with the GT1, DIS software) and I was still running rough. I put the engine at TDC with the locking pin in place and I'll be damn, the exhaust cam is about 4-5° retarded. How did I miss that since I checked multiple times, errgg. Fixed that and all smooth again, whew! Now go for a test drive and any hard acceleration over 3000 rpm and it starts to run rough and the CEL comes on. computer says misfire cyl 6 so I clear the code and it comes back again. Cylinder 6 has a new coil pack on it because I found out early on that cylinder was not firing and when I swapped coils the problem followed. Well, now the new coil pack failed! Put a new one in and problem solved. Drove for a bit and CEL comes back on again and this time it is bank 1 pre-cat o2 sensor, which is also new. Put the old one back in and problem solved. So much for new parts although I admit they were not OEM parts.

I had the check engine light come on again and this time it was in the transmission module, said excessive torque converter slip, dang! Cleared it and would only come back on if I was hot rodding around. I left the light on and just took it easy for awhile and then the light went off by itself and has not come back on. I think after sitting for such a long time things just had to work themselves a bit.

This vehicle is just way beyond my expectations to drive. I had a 2001 X5 4.4i I thought was pretty fun but this 4.6is is in a whole different league! Anyone want a 2000 540M Sport? I want to replace that car with another X5 either 4.6is or 4.8is.

Thanks to all those who chimed in with support, I really appreciate that. After reading so many threads with dead ends I didn't want to be that guy so now I am at peace with myself for providing a conclusion to my quest.

Now I just need to figure out why my drivers side headlamp is much dimmer that the passenger side.

Best regards,
Tim

[bcredliner]

Thanks for the update!

[J.Belknap]

Glad to see you got the timing and etc taken care of. Good work.