I have a 2009 535i with 105K miles. The CEL came on while driving normally and my reader came back with a P1074 lean code. After doing a bit research, it pulled off the engine cover to check for vacuum leaks. One of the problems I found is that the valve cover appears to be leaking on the interior side (see picture). Could this be causing the code or would both banks come up?

While searching the internet, I saw videos of foggers being used to detect leaks. I have a a halloween fogger which I can probably rig up, but I don't want to damage the MAF. Will the fogging solution damage the MAF?

Thanks in advance.

 

I can't really answer your fogger question, but if you've never done the VC gasket, you may as well just replace it. It should be done around this mileage regardless.

 

I took the car to my local BMW independent. He found a cracked valve cover and failed PCV system (integrated into valve cover I believe). All covered by my extended warranty.

 

I had the same code when I had my 04 530i. Went and got opinions over and over and changed out everything I was told 02 sensors the cam shafts sensors the mtf and coils bc of misfires. Well it turned out to be the "manifold adjuster unit" there's a plastic flap that broke off on the corner. I changed it and all code went away.

 

I have had the same code for about 2 years now. Posted about it a few times. Under warranty BMW replaced a cracked valve cover and could not find any other reason for the code. Just kept reseting and sending me on my way.

Now out of warranty, it just stays on. The car performs great. I found a new indy and will take it up to them soon. Will have them check the PCV system. Thanks for let us know.

 

Check the manifold adjuster unit aka: DISA valve. I went to the dealership also and they did everything but pull that unit out. It slides out like a ink cartridge in a office copier, My indy pulled it out and sure enough the flap was broke off on the corner. That flap opens and closes. If it stays open or can't close boom code city. You can buy another flap kit cheap or the whole unit for about $254 online.

 

Will do! Thanks.

 

535 doesn't have a disa valve but the valve cover being cracked around the fuel injector spark plugs well is pretty common. Hard to spot but I've replaced several for the same issues

 

My cover has been replaced and BMW still couldn't figure out (or didn't try to figure out) why I keep getting the lean mixture code. Again it runs fine.. so I haven't fiddled with it since its my dime now out of warranty. Any ideas where to look if I don't have a DISA? Sensors bad?
Thanks

 

plowery21, How many miles on your n54 at the time of cracked valve cover replacement and how many miles now?