Mark7000

97k miles 2010 base 3.6 v6

Vehicle was running fine. I was going to replace the coils/plugs just due to mileage reasons and had to go out of town for 2 months. Had not actually replaced them though. Got back last week and soon upon starting up it was running rough, threw codes for idle lean bank 1, idle rpm higher than expected, etc. It also made an occasional squealing noise like an alternator or tensioner would make but not from the driver's side where they are located. this was coming from passenger side. Maybe sitting for 2 months caused sound?

I thought, well, I need to go ahead and replace the coils/plugs since I already had them. (Got to use the "mystery tool" for the coils. LOL)

Started it up - no real difference even tho the old plugs were not in great shape.

Then heard some weird thumping noises like air coming out somewhere? Idle began doing a weird surging from normal to 1500rpm.

OK - so I have an air leak downstream of the MAF - makes sense, right? Air was getting in somewhere that the MAF wasn't metering. Maybe a cracked hose? I took the air intake hoses off and even removed and cleaned the throttle body. It was in decent shape and so was the rubber gasket. However, inside the intake, just past the throttle body, I noticed a light film of clean oil all over. I cleaned as much of that as I could and re-assembled everything. Again, no difference and get the same codes and surging idle. Squealing noise hasn't come back either. Car is always in a dry garage.

Symptoms pointing to the AOS.

My question is, where is the AOS on the v6? I can find all sorts of v8 pictures and tutorials, but nothing looks like this on the v6?

Dilberto

V6 has no AOS... you got a massive vacuum leak.

Mark7000

Then what explains the light film of oil inside the pass side plenum for the intake, just past the throttle body? What equivalent PCV system does the v6 have?

Jbdehoyos

It's in the valve cover for the V6. Diaphragm goes bad and needs to be replace. Porsche only sells it with the valve cover not separately.

Jbdehoyos

I just completed this on my 2010 V6. My diaphragm did have multiple cuts, replaced and put back together, runs like a charm.

gjsauser

Which valve cover is it under, passenger or driver, also do you have any info or directions on the swap? I have seen info on how to do it on the v8 but not the v6. Thanks

PTEC

There are no separate banks on the VR6, its essentially the same as a inline engine.

deilenberger

You may want to check your reference sources..

https://vanos-bmw.com/diaphragm-valv...nne-3-6-m55-01

http://www.klaindustries.net/diaphragm/air-oil.htm

gjsauser

Thats what I was afraid of, looks much simpler on the V8 engine....

Greg Brown

Was this a hard fix? How long did it take you? I’m having exactly the same issues as the OP, so I just bought the diaphragm.

Greg Brown

Did you ever get this figured out? Mines doing exactly the same thing even the sound of a belt squeal but it sounds like it’s coming from passenger side behind the engine.

desmo888

I'm getting ready to do mine. Getting the part is a little tricky. https://vanos-bmw.com/ has the membrane - $30 shipped from Russia.

I'll be doing a video on replacing it. There's already a good video on getting the valve cover off, I'll just cover the membrane replacement.

mdistel

I ordered mine from RXK tech. Lots lof threads covering the replacement and on another forum there is a DIY. I did the job in December on my 2009, it was a challenge. Make sure you buy new vacuum lines bothe the corrugated one that runs above the exhaust and the brake booster one at the rear as they will crack.

Mark