No boost, car runs fine, just gutless.

[COTT3series]

So in my 08' 535xi I have been intermitently experiencing these bouts where the car has zero boost and no codes unless I try to go wot, in which, I get the 30ff underboost code. I've checked the vacuum canisters, lines, diverters, etc but I don't think this is a leak.

Anyone have any similar experiences? The car runs great, has a slight misfire at idle but doesn't throw any codes for it and runs absolutely fine and smooth apart from not having any boost. The misfires at idle come and go periodically furing driving. At one light it'll miss a little and the next not at all.

Thanks!

 

[Derek@MoorePerformance]

Kinda sounds like the infamous wastegate issue.

 

[COTT3series]

Kinda sounds like the infamous wastegate issue.

I was thinking the wastegate(s) might he getting stuck :/

 

[Derek@MoorePerformance]

I was thinking the wastegate(s) might he getting stuck :/

Well, if it is underboost then... It is likely being held open more than it is supposed to. It might close correctly and that can cause a spread of different issues on its own.

 

[COTT3series]

Well, if it is underboost then... It is likely being held open more than it is supposed to. It might close correctly and that can cause a spread of different issues on its own.

Hmmm all I know is it's gutless and I hate that :/

I thought about replacing the boost control solenoids but don't want to throw money at parts.

 

[Derek@MoorePerformance]

Do your turbos rattle?

 

[COTT3series]

Do your turbos rattle?

Nozzir.

 

[Derek@MoorePerformance]

Are you getting any smoke? If so is it dominant out of the left or right exhaust?

If no smoke when was the last time you checked your system for boost leaks?

Have you checked your PCV port to ensure its making connection to the rear inlet(assuming stock inlets)

Have you logged any?

 

[COTT3series]

Are you getting any smoke? If so is it dominant out of the left or right exhaust?

If no smoke when was the last time you checked your system for boost leaks?

Have you checked your PCV port to ensure its making connection to the rear inlet(assuming stock inlets)

Have you logged any?

No smoke, fairly positive it isn't a leak as there is literally zero boost. Turbos aren't even spooling.

Haven't checked the PCV port. My laptop crapped out on me (POS PC) so I haven't been able to connect to the procede to get a log.