[sannouni]

Hi everyone,

I was working on my friends car over the weekend (replacing the Glow plugs on his 2009 335D Automatic), everything went smooth, torqued all the intake manifold bolts and nuts to spec (with new gasket set), changed the glow plugs and their controller (which is also in the vicinity)

after the work was complete, started the engine, it idled smooth. while test driving the car, we noticed that there was a clear loss of acceleration (it's as if the engine is bogging down, or is choking) until RPM reaches around 2500, then the power comes at a big surge (as if nothing is wrong).

we reopened everything to make sure that the work was done correctly, and it was... we put the car back together. the problem is continuing...

the engine codes are
P0299: Turbo Under-boost Condition
P2457: Exhaust Gas Recirculation (EGR) Cooling System Performance

any help and or ideas would be greatly appreciated.... thanks

[dixy2k]

My car performed similarly, but I had a different fault code. The dealer replaced all the injectors.

[GreekboyD]

Could be the turbo actuator on the smaller turbo but I can't see how this was caused by simply changing out the glow plugs and module.

Did you check the vacuum hose going to the smaller turbo?

[sannouni]

thanks for the replies
GreekboyD, I did not look at the Passenger side of the engine compartment at all, could it be possible that while we removed the engine cover (to expose the intake manifold) that we knocked something off it's place? I'll ask them to have a look and see if anything is out of place there...
any more ideas?
could this have anything to do with this ? (following link) : http://www.e90post.com/forums/showthread.php?t=321049

[GreekboyD]

Originally Posted by sannouni

thanks for the replies
GreekboyD, I did not look at the Passenger side of the engine compartment at all, could it be possible that while we removed the engine cover (to expose the intake manifold) that we knocked something off it's place? I'll ask them to have a look and see if anything is out of place there...
any more ideas?
could this have anything to do with this ? (following link) : http://www.e90post.com/forums/showthread.php?t=321049

I'd check around the smaller turbo first. My buddy changed his glow plugs and module last month and didn't need to do anything with regard to the link you posted.

[sannouni]

the procedure for the throttle body re-adaptation was done, no significant improvements.
other than that, everything seems to be in place... is there an easy way to check the small turbo (i'm guessing one place to check would be the wastegate valve, it could be stuck open preventing the turbo from spooling...??)
where is the small turbo wastegate valve actuator rod ? is it visible from the top of the engine ? also, what else to look for on the turbo ?

thanks for the suggestions

[sannouni]

I was reading more about the turbos installed on this car... there is a lot of vacuum control...

are there any vacuum lines/control running in the back of the engine (along the firewall)?? the reason why i'm asking, is that this is the only place that we havent checked... and we had some issues removing the rear cover of the engine (the one closest to the firewall)...

also, when i removed the intake manifold, there was no vacuum lines attachment to the Manifold (unless i messed up big time, but i checked twice, there was none)

any input is appreciated... thanks

[rogerdiaz]

When should you change glow plugs?

[sannouni]

Rogerdiaz, if there is no CEL, i wouldnt worry about them...

Can you guys confirm that the exhaust manifold valve (as in the video link below) operates as soon as you turn on the car?

for the car that i'm diagnosing, this valve does not operate upon starting the car (or at any time after).... i know that this valve is actuated using vacuum....

Any input is appreciated... thanks

[sannouni]

no one ?

[Ajs_435d]

My car has done 95k as I cleaned the intake manifold I decided to replace the glow plugs since I already had manifold off, glad I did. One was nearly seized in and were likely going to fail soon. My car expelled bit of smoke on cold start up, after changing it started a little easier and didn't expell as much smoke, I'm stage 2.

[joe_planet]

when I was getting a turbo underboost condition error there was some sort of electrical vacuum actuator unit that they replaced that fix the issue.

[Hoooper]

definitely make sure you check the operation of both the vacuum controller (turbo actuator) and the vacuum lines themselves. There shouldnt be any vacuum lines to the manifold as the manifold is never really under any significant vacuum. Did you check to make sure all of the electrical connectors are connected, particularly the MAP sensor on the manifold?

[sannouni]

I confirmed that every electrical wire in or around the manifold is connected.

There is a red'ish vacuum line that runs from the passenger side vacuum loom to the front of the engine. .. I found that to be a little damaged ( cracks and burn marks on the braided part of the vacuum hose)

No One can confirm that the turbo actuator valve rotates upon starting the car (as shown in the video attached above)??

[Hoooper]

I will try to take a look tomorrow if I start the car at all. Hard to tell from the video but is that the small turbo in the video?

[sannouni]

Hooper, thanks.. that would be great
The video above shows the small turbo.. right under the small turbo towards the back you will notice a small metal bar that connects to valve in the video (the first few seconds of the video show the valve that rotates when the vehicle is started)