[Kangarooski]

Making another post here as more people may see it.

2007 335i, 107k

Car is making no boost, had a Jb4 on prior and it registered 0 boost, I removed jb4 as I had planned on selling the car soon anyways. Still no boost, looked for vacuum leaks and ended up replacing all the vacuum hoses and still nothing, not a sound from the turbos and still no CEL.

What would be the logical next place to look? If the wastegates weren't closing would that make any sense? It is my understanding that the car would still make boost.

Any help or ideas is greatly appreciated.

[335NJ]

Vacuum solenoids, all charge connections too. No codes and no boost is odd

[Moutamid]

Originally Posted by 335NJ

Vacuum solenoids, all charge connections too. No codes and no boost is odd

did you checked boost solenoids ?

[Kangarooski]

The charge connections appear fine, I checked those initially.

Is there an easy way to test the solenoids? I made sure the electrical connections were seated fine but that was it.

[Kangarooski]

Hooked up a BT reader to it and the only fault that was logged but not current was


code:2A17 DMTL

The DMTL (Diagnostic Module Tank Leakage) pump tests the fuel tank and fueling components for leaks by slightly pressurizing the fuel tank and evaporative components. The DMTL pump contains an integral DC motor which is activated directly by the ECM which then monitors the pump motor operating current as the measurement for detecting leaks.


so yeah, don't think that did much good.

[335NJ]

Similar issue thread: http://www.e90post.com/forums/showthread.php?t=1003570

Search your ass off, and usually you'll dig something up

[Kangarooski]

interesting, well there is still some hope then, looks like I'll dot i's this weekend.

thanks for the link, that was one I have not seen yet.

[335NJ]

Originally Posted by Kangarooski

interesting, well there is still some hope then, looks like I'll dot i's this weekend.

thanks for the link, that was one I have not seen yet.

No problem, just do things one at a time obviously. I tend to try 15 things at once, and never know which of the 15 fixed the issue

[Kangarooski]

I know the feeling, haha.

I have just spent hours and hours reading through threads about boost issues, that one is the first that matches entirely. It just blows my mind that this would not throw a code or ten.

[335NJ]

Originally Posted by Kangarooski

I know the feeling, haha.

I have just spent hours and hours reading through threads about boost issues, that one is the first that matches entirely. It just blows my mind that this would not throw a code or ten.

It's weird, modern cars will throw a code for the craziest things, but when it's a major functionality issue like this, there's nothing. I'm surprised another member hasn't jumped in this thread with the exact solution to the problem you're having yet, since half the time I read these threads, someone who is borderline Bill Nye of the BMW world has the answer to a tee.

Whatever you do, try to record what you did, and update this thread. Too many help threads get left unfinished and typically fail on helping the community

[Kangarooski]

yes, for sure... that has been the frustrating part while going through threads, most of them are never concluded it seems.

[CoralRed335XI]

When my charge pipe popped off my intercooler tubing, i had the same issue. Does you car have a deeper exhaust now as well?

[Kangarooski]

it doesn't seem like it's changed much, would it be really noticeable??

[335NJ]

Originally Posted by Kangarooski

it doesn't seem like it's changed much, would it be really noticeable??

I think he's implying the wastegates would be stuck open, which would mean exhaust note naturally gets louder, have someone rev the engine a bit with you under the hood to really hear it, along with any other odd out of place sounds.

[Kangarooski]

Still no boost

[335NJ]

Originally Posted by Kangarooski

Still no boost

If you truly can't figure the issue out, it would be worth your while to take it to a good Indy shop who knows this engine well.

[Kangarooski]

I'm trying to schedule a guy from the forum here to take a look. Hopefully next weekend.

I went over all the vacuum and charge pipes again and still nothing.

[Kangarooski]

not much of an update, Rechecked all the vacuum lines, removed the charge pipe and reinstalled to make sure there weren't any cracks that I couldn't see. I reinstalled the Jb4 as a wildcard...

nothing. The boost gauge drops like it would normally under load but no boost builds.

[Kangarooski]

I should add that it looks like they are the original turbos, but at no point in time have they made an irregular sound, bearing or otherwise, and at no point in time has it dumped any noticable smoke.

[335NJ]

Post a .csv (datalog file) over to the support section of N54Tech. Maybe Russell can see something through the logs. List the issue you're having, etc.

[Kangarooski]

holy F**k me, I have mother F***ing boost again.

The front wastage actuator vacuum line that I had replaced was the culprit. I checked over things for the 100th time and somehow it was not seated correctly. My hands aren't exactly small and that is the awkward as hell one to get to.

This was enough, and simple enough to drive me insane.

So that alone caused 0 boost and no CEL, now the car boosts just as it should.


tl:dr FML

[Seven11]

glad u fixed your problem!!

these things can stress a person out!