or_550i

Some of us get it. There will always be the kid who tries to hammer the square peg through the round hole.

1diver1

Thank you. I did go get the MAF cleaner today and try that, didn't work. I'll look at the vacuum leak tomorrow, Thank you again for your advise.

1diver1

Am I the OP? I do appreciate your advise. Since your original post I haven't said anything to the contrary? I'm taking it to a different shop tomorrow, I'll ask that they don't do anything but replace the pressure regulating valves first then call me..Thank you again, I really appreciate it.

1diver1

Just got back from the other shop. They said both Crank Case Vent Valves were shot. He didn't have the part but will next week. He said he's 90% sure that's causing the problem. He really wondered why the dealer would try the thermostat first and then try to replace the fuel pump. They did a smoke test and didn't find any leaks.

05545i

See? I could have saved you 500$!! This is a very common problem. Dont trust that dealer. They have absolutely no idea what they're doing. Those valves will not show up in a smoke test. The vacuum leak is internal. You will never see it.

1diver1

I know. Lesson learned. Are the crank case valves different from the pressure control valves and if so; are they as easy to replace? Meaning I could do it?

bmwroger1

the crank case valves are the pressure regulating valves. and they are very easy to do. bmw's do not have pcv valves. but they have pressure regulating valves. which is there version of pcv's. all you had to do to replace them is take out the engine cover, and both side covers covering the rocker panel. there is one valve on each side. they look round closer to the front of the engine. on the passenger side it is just above the vacuum pump. and on the drivers side it right above the snorkle for the air intake. good luck and keep us posted.

05545i

The pressure regulating valves act as the PCV valves. Very easy to change. Remove the acoustic cover (4 bolts). Remove the cylinder head acoustic covers (pull right off, snapped in). You need only some rags and a small flat head screw driver. That is it.

Cobra 427

I guess I meant Crank Case Vent Valves...

luigi524td

Now that I'm thinking about it more I remember this was a fairly common problem on both of my V-8 740's. There was something akin to a PCV buried in the V at the rear of the engine. When I told my mechanic the symptoms (poor low speed power, rough engine at low speed and then stalling at idle) he said YUP ... called it a plate something or another. I brought it in, was a one-hour labor + $90 part and back on the road smooth as silk. The device was about 4"x6", had a few rubber hoses attached and a gasket inside that was known to fail at 60-70K miles. The assembly could not be repaired - go figure and was a known failure problem on those V-8 cars!!

Guess the new V-8s have similar problem parts and no one has engineered how to make them stand up to engine gases and heat. Sounds like a job for NASA!!