Hi all

I recently had a brand new engine, turbos and exhaust system fitted all proffessionally done by williams Bmw, due to flood damage to the engine causing the engine to hydraulic.

The car now runs sweet 6 days a week but what seems to be at least once a week the engine looses power when putting my foot down i have to put the pedal down at least halfway before the power will kick in sometimes throwing me back in the seat, there seems to be a huge turbo lag ???

Ive had it back into them twice but low and behold the days its booked in its running fine and dandy, the service guy told me to take it in next time it does it as there are no faults reported, but again as luck would have it it seems to play up over the weekend.

It will be like this for half a day, a day and sometimes a day and a half then it will just go back to normal for another week or so, Ive also noticed that when its doing this i can smell a burning smell, a bit like a burnt out clutch and the underside of the car clicks as if red hot ???

Any ideas Please !!!!

 

Sounds like something is wrong with the smaller turbo or plumbing for it... This would explain the huge lag.

 

Could be the Particluate Filter in the exhaust going through a 'burn' cycle?? How many miles are you covering between these incidents?

 

Once a week so maybe about 300-400 miles,

I first thought it may be a turbo problem because of the lag until one night when it was doing it i walked around the back of the car and could feel the heat just standing behind it which seemed to be coming from the exhaust this lead me to believe it was more of an exhaust problem, i also get a much stronger smell of burning from the back of the car and it seems the whole exhaust system is boiling hot causing it to click.

Is this burn cycle normal ? and could it cause the car to lose power ?

 

As far as I know the exhaust will burn hotter and you may get a smell when the particulate filter is cleaning itself. You may also see the car holding onto gears a little longer to keep the engine speed (revs) up. Not sure how often this should happen - once a week sounds to often. . . no harm in asking your dealer as this may indicative of another problem or pending failure.

I have covered ~ 55,000K in my 520D and only noticed this happening a couple of times.

 

MAF sensor anyone ?

mine did this... and it was the MAF..

 

Hi, have you had the car back into the dealers so they can put it back on diagnostics. The fault does not have to be there as the dis system will hold many faults until cleared by their computer. So i would get it back into them. If it is a sensor or module or wiring then it will store the fault.
cheers