My 335 is running rough, very rough in colder weather when it's still warming up, to the point where it has stalled out a few times and is a ***** to get running again. For some reason the idle roughness dies down once it's at operating temps.

Under WOT and full boost it starts making this crazy thumping sound, and the limp mode immediately engages. Have to use the JB4 to clear the codes and remove the limp mode.

I'm thinking it is coils, spark plugs, or injectors. If I avoid WOT full boost it still pulls pretty good, breaks traction easy...it's just not handling full boost well.

Instead of having the dealership possibly f something up, does anyone know of a good indy shop I could drop it off at so they could investigate? Preferably one that is focused on bimmers or the n54 motor. Looking to avoid any trips to MD. Thanks.

 

RRT in Dulles

 

Just remember what BMW stands for: "Bring My Wallet"

 

Sorry to hear this.
I've read that the JB4 has a few issues, therefore I went ahead with the Cob which is easily reversible to stock form if needed.

Keep us posted...

RRT comes highly recommended.

 

Awesome, I'll look into RRT, thanks.

 

Give Advantage Certified a call, they are in Manassas off hwy 28. They specialize in BMW's (sales and service). They work on my 07 911 TT and my wife's 06 X3. IMO., they are the best in NVA.

 

Green Motorsports in Springfield. They do all the work on my 997 TT. Let them know that Angel sent you. They will take care of you. PM me if you have any questions.

 

You can also try CoHo automotive in Manassas... It's run by Chris Coulter from Curry's, and Dan Howell...

 

RRT or Funktion auto in Sterling. Sounds like maybe you could be having an HPFP issue if it hasn't been replaced. You should find somebody with a scan tool to see what codes you are throwing.

 

Update:

Took it to a generic auto place to have the spark plugs replaced. This fixed the massive hesitation jolt on full boost in third gear....but, the car still ran like **** and was stalling out.

It's funny how crappy it runs at idle, but WOT I can spin the tires in third gear, pulls like a train.

Anyways, dropping the bastard off at RRT tomorrow. They think (and so do I) that it will come down to intake cleaning (walnut shell blasting) or injectors.

I'm placing bets on the intake cleaning.

 

Direct injection in the bmw=horrible carbon buildup!

 

Hills Garage in Baltimore/Brooklyn Park.

Frank Smith tunes out of one of their shops...no one on the east or west coast better IMO.
Time to add a little methanol to the DI335TT

its not VA but no place better, I dont drive my car there, because I enjoy the 50+ miles one way trip from Herndon, its because when I leave I know its done right.

 

+100 as I know Frank personally!! Great guy and one of the best tuners out there.

 

Fixing it to get rid of it.

 

Turned out to be a couple hoses near the throttle body that were unplugged and some other things causing a vacuum problem. RRT FTW!