[imolaman]

Good day all,

Recently my car, a 2001 M5 started going into limp mode whenever I push it in 4th, 5th or 6th gears. It goes into limp mode at around 4000 - 5000 rpm. The "stealer" diagnosed it as being a dirty fuel filter and faulty fuel pressure regulator. As I am in the countryside parts take a few days to get here so it's still with them. Anyone experienced similar problems? The car has done 84 000 km without any problems to date.

 

[DavidS]

If the fuel pressure is not correct it could definitively give the problem described. Be happy the filter was there and got clogged and not an injector. The filter and regulator are not too expensive to replace.

I hope that fixes the car!

David

 

[stever]

i had this problem caused by the MAFs -- car would run a little rough when first started, but was okay around town -- then after running hard for a while it would shut down suddenly as the air-fuel ratio reached a limit

after the error codes were cleared it ran fine for a while until again the MAFs couldn't adjust the mixture any more, then shut down again -- replacement covered under emissions warranty at 38k mi

 

[kjell]

Had the same problems, MAFs changed and now it runs very good

i had this problem caused by the MAFs -- car would run a little rough when first started, but was okay around town -- then after running hard for a while it would shut down suddenly as the air-fuel ratio reached a limit

after the error codes were cleared it ran fine for a while until again the MAFs couldn't adjust the mixture any more, then shut down again -- replacement covered under emissions warranty at 38k mi

 

[imolaman]

Thanks David,

The new fuel filter is being replaced and will pick the car up tomorrow. Regulator is being ordered from Germany (this is South Africa) as no dealer stocks the part. M5's are a rare sight over here, with M3's being driven by every man and his dog. Suppose you're right, filter & regulator much cheaper than injectors. Mechanic also tells me wires for the lambda sensors were all connected up the wrong way. Wonder if this could have contributed to the problem.

Good BMW dealers are hard to find here. The only really good one close to home in Benoni closed up shop two years ago, so I'm now relying on the ones left...

Cheers,

Rudi aka imolaman

If the fuel pressure is not correct it could definitively give the problem described. Be happy the filter was there and got clogged and not an injector. The filter and regulator are not too expensive to replace.

I hope that fixes the car!

David

 

[mottati]

Thanks David,

The new fuel filter is being replaced and will pick the car up tomorrow. Regulator is being ordered from Germany (this is South Africa) as no dealer stocks the part.

Cheers,

Rudi aka imolaman

Interesting, i had my fuel filter replaced (cost was under $100 US) and the filter and regulator were one piece! (hence the high cost for a filter).
Mike

 

[DavidS]

Rudi,

If the lambda sensors have been connected incorrectly, ask them to clear the adaptation memory in the DME. This will set everything to factory defaults, which will be close to what you should have with a new fuel-filter and correctly connected lambda-sensors.

Take a look at

http://www.m5board.com/vbulletin/showthread.php?t=54359

regarding how to test tye MAFs.

Best Regs,

David

 

[imolaman]

Mike,

Quite right, it is one piece, although the pressure regulator can be taken off. The filter these clowns had in stock had no pressure regulator attached to it hence the old one was reused.

By the way this did not solve the problem. We also changed the MAF's (as per Steve's suggestion). I like the site explaining how to clean them, although will only try it myself once motorplan has expired.

I just read the thread from ContactR re his engine trouble. Symptoms are exactly the same. Currently posting to him as I did not see a solution from him that worked.

Car is now at my home dealer. Hopefully that will help.

Cheers, Rudi

Interesting, i had my fuel filter replaced (cost was under $100 US) and the filter and regulator were one piece! (hence the high cost for a filter).
Mike

 

[SC'dKellenersM5]

hmm, interesting. Im having the same issues right now with mine as well...although the mafs have only about 5K miles on them

 

[stever]

my understanding is that cleaning the MAFs is a fairly short term solution

talked to someone who has changed a lot of them and feels that the failure incidence increases in rainy weather and with cold air intakes