[CEW]

I have a 2008 335i. I was driving on a two lane highway and passin a number of "slower" cars when I got the 1/2 engine light, engine malfunction, reduced power message. I took it into the dealership and they said the vacuum pump needs to be replaced. When it comes to engines my knowledge is limited. What is the vacuum pump and what would be common symptoms of a failure. Besides the 1/2 engine light?

[mubay]

I got the same problem on my 07 335i. The light comes up if I push the gas more than 4k rpm. However, the engine malfunction light is gone every time I restart my car. Anyone can help?

[H4n]

Originally Posted by mubay

I got the same problem on my 07 335i. The light comes up if I push the gas more than 4k rpm. However, the engine malfunction light is gone every time I restart my car. Anyone can help?

That happen to me also. Bought it to the dealer and found out the vaccum line going to one of the turbos wastegates was leaking and throw the code. They replaced it and it went away. But now I think I have the same thing again? Maybe it happen to the other turbo wategate now??

[Bobble]

Took my 08 in Monday for same thing, hopefully it does not repeat itself as a tune is next and I'd hate to reflash for something like that.

[raceyBMW]

If its the pump, then its kind of a big deal, because the pump is connected to the front of the HPFP and is driven by the timing chain drive. Not an easy repair.

[Bobble]

I dont have the work order with me but mine they replaced a tnak and the hose for cylinders 1 thru 3. That repair was done in a half day so I highly doubt it was the pump based on that.

[raceyBMW]

No, you just got one of the accumulator tanks and a hose going to the wastegate solenoid replaced, that is easy and relatively cheap work. Vacuum pump requires diving into the engine.

[H4n]

welll my cars back to the dealership, found out yesterday the true problem is indeed the vacuum pump. He said it should take a few days to replace it. What does the vacuum pump do?

[raceyBMW]

Provides vacuum to control the wastegates, brake booster, exhaust flap control, emissions pump, etc. (there might be others, but I can't think of them right now).

Usually, on a normally aspirated car, the intake manifold would always be at pressures less than atmospheric and provide the vacuum needed to run all of these items (even though you wouldn't have wastegastes). However, boosted cars require a vacuum pump to run the items above because the intake manifold is most of the time above atmospheric pressure, unless you are decelerating or idling.

[H4n]

Ic, thanks for the info. Hopefully this will fix my half cel.

[Cyruz]

just my car diagnosed with the same after a long series of dealer visits of the past 2-3 months. anyone have this happen a second time to them? apparently the diaphragm is leaking.