So I am driving my 545i at a speed of 50Kmh, feathering the gas pedal, and all of a sudden there is big bang, the car jumps as if the car is changing gears but it's slamming so violently.

This only happens on occasion, I am wondering if this is a transmission issue or an engine issue?

Thanks

 

Maybe get your SA to do a software update. I had a similar experience which was resolved after a software update.

 

Thanks, I am due for a software upgrade first week of May. They couldn't schedule me any earlier.

 

No worries, I hope this update helps.

On another note, we don't get many 545's here in the UK, but saw one whizz by the other day on the M1 motorway. Was a beast! Must be amazing to drive. Over here 535's are seen as the daddy's on 5ers until you get to the M's!

 

Well the 535 with a software upgrade could produce 400HP!!
The turbos on the 535 are way under utilized

 

i wonder what the stock max boost is on the turbo engines. maybe 8-10 psi??

 

i just bought my 2008 535xi couple months ago and wanted to upgrade my ECU to get more out of the turbos...do you suggest a system thats user friendly or gets the best bang for the buck?

 

I did the Dinan Stage II for $2000. It matched the BMW 4years/50,000 warranty including incidental repairs. It gave 384 hp and 421 ft/lbs.
Never had a problem.

 

I was just able to reproduce this issue and hope it's not a major problem

The car stutters every 5 seconds when it's in fifth gear (especially when in DS mode or M mode) basically the engine stutters as if it's being cut off from the fuel supply when feathering the gas or accelerating. This is not the transmission I think as the car is not hunting for gears.

This is more engine related, however nothing happens when is 1st,2nd 3rd, 4th or sixth gear. Very interesting!

Any idea why this is happening?


2004 545i automatic.