[Edge Iron]

While driving home my car essentially goes into Limp mode. Here's the odd part. It throws no codes and no check engine lights. It will do it after a WOT pull and after about 30 or so minutes of driving. If I turn the car off and then turn it back on, everything is fine again. It has done it 3 times over the last week. The first time it did it it was before I installed my CP and FMIC, so I don't think those caused it.
So basically I do a WOT pull and then when I let off there is a very small blip and the car gets louder (Wastegates opened?) and when I accelerate the car has no power. I can still rev it up pretty high but it won't pull.
Any ideas?

[mweisdorfer]

Originally Posted by Edge Iron

While driving home my car essentially goes into Limp mode. Here's the odd part. It throws no codes and no check engine lights. It will do it after a WOT pull and after about 30 or so minutes of driving. If I turn the car off and then turn it back on, everything is fine again. It has done it 3 times over the last week. The first time it did it it was before I installed my CP and FMIC, so I don't think those caused it.
So basically I do a WOT pull and then when I let off there is a very small blip and the car gets louder (Wastegates opened?) and when I accelerate the car has no power. I can still rev it up pretty high but it won't pull.
Any ideas?

Probably your HPFP or maybe your vans solenoids. Its worth cleaning the vanos solenoids; all you have to do is soak them in gas for an hour and then blow them out with an air compressor. If I had to bet, your HPFP is gone or going. If it boggs down before it goes into limp mode while your in WOT, you may have a leak in your charge pipe.

[bcg]

I had this problem recently, it was a bad throttle body. Do you see any RPM surge when it happens?

[wholc]

I'm having the same issue with my stock N54. Only happens after car has been running ~30 min or more. Only happens with prolonged WOT pulls, 3rd gear or greater.

Stock, 134k miles, new (< 5k) injectors and LPFP. HPFP was replaced under warranty around 90k I believe.

Oil filter housing gasket needs replacing, will make sure to look for leaks in charge pipe/throttle body.

I'm interested to see what your diagnosis is.

[Edge Iron]

Ive been out of town for the last few days so I haven't had a chance to look at much. Going home from work on Thursday I tried to replicate the limp mode. I never got it to go into limp mode but for a moment it almost seemed like it wanted to. I think I am going to start with inspecting the vacuum lines and probably replacing the wastegate solenoids. I had a problem ever since I got my tune with the Overboost code, although I am no longer throwing that. After that I'll try checking the DVs. I would think it could be my FMIC or CP, but I had this issue before I installed them. When I go under to do my DPs, I'll take a look at my connections and see if I can improve them at all. I'll check ut my throttle body as well, make sure it is cleaned and all. There was a bit of an oil sheen on the inside of my stock CP, so that could be causing issues as well.

[buly34]

Ever figure this issue out? I am having the exact same issue with my car!

Please let me know!

[Mike@N54Tuning.com]

Any chance your tune is auto clearing the codes?

Mike

[buly34]

Mike please read my current post and let me know if you can help...

http://www.e90post.com/forums/showth...9#post19039729

[Mike@N54Tuning.com]

Originally Posted by buly34

Mike please read my current post and let me know if you can help...

http://www.e90post.com/forums/showth...9#post19039729

I replied over there.. You need to log it if your tune has logging capability. Without a log or a code its difficult to diagnose. Flash back to stock as well and see if problem persists.

Mike

[limitdown]

As Mike said, it's almost impossible to pinpoint the root cause without reading codes or logging. The cause could literally be dozens of different items.

Sometimes codes and problems only appear when pushing the car hard, because that's when the weakest links become evident. It's like my bad knee from a high school injury. It works perfectly until I WOT my running speed.

Regarding reading codes, I've used generic cables, Bluetooth dongles and apps that failed to correctly read BMW-specific codes.

[musa]

I realize this is an old post but it captures all the nuances of my issue pretty good. Any one figured out what the issue was?

[MakkkD]

Ttt

[musa]

Originally Posted by musa

I realize this is an old post but it captures all the nuances of my issue pretty good. Any one figured out what the issue was?

Update: Replaced the DME and its cooling fan and all is well now. Cost $1,500 including install and coding. Got a great deal at BMW Santa Ana. I learned after the fact in e90postforum that a complete recoding of the old DME at the dealer probably would have fixed my issue. In any case the car runs fantastic now. The error code thrown after the limp mode was always:
-5E19 dsc 5E19 CAN DME/DDE Torque Reduction Not Possible; engine torque not adjustable
-2D58 DME maximum clutch torque implausible (internal failure: control nominal torque)