[Monster335]

My car has bms dci, vk downpipes, ets 5" fmic and running cobb v401, ran like a champ, then i decide to add ets charge pipe with tial bov, also ran good for few weeks but there was a sound from the bov from the initial install (sounds like a squeaking brakes) and this only happens when throttle is closed or especially when im going to a stop. Or when im am idle i will rev the engine and when i let go of pedal i hear that noise at the end. Spoke with ets and he thinks there is a vacuum leak.

Took it into bmw and my tech did a smoke test and found that one of my intake valves were cracked so he replaced it. Also want to mention that the cobb tune was fully uninstalled at this point, so we know its not tune related. Took it home and next day service engine soon light comes on again.

Took my car in yesterday and did another smoke test and looks like there are no leaks. My tech says he ran out of time so tomorrow he is going to smoke test the exhaust and double check everything again cuz he says the car is still running too lean.

Anyone know what this might be or have had same issue before? if so, what was the fix or what could we look for?

thx

[JamesM3M5]

Need to see engine adaptives - part throttle multiplicative % to see whether the problem is isolated to bank 2 only or bank 1 is really close but just hasn't set the code, yet. BT tool and other BMW diagnostic computers can see this info. Could be a bad injector if it's only on a single bank. If it's on both banks but bank 1 just hasn't reached the threshhold to set a code, then you have some other problem.

[Monster335]

Thanks....I also did some research and there are few possiblities...My plugs, coils, and injectors were recently replaced, so slim chance it may be those but im sure my tech will check it, but see this problem is caused by either leak or maybe o2 sensor....what do you think?

[enrita]

i was getting lean codes with a huge leak. So might be that.

[Monster335]

Could you tell me where the leak was? And how you found the leak? thx

[enrita]

Originally Posted by Monster335

Could you tell me where the leak was? And how you found the leak? thx

just do a smoke/pressure testing and check all vacuum lines , dvs etc. leaks can be everywhere.

[Monster335]

so my tech pretty did the smoke test again and he also took apart some of the parts like intake and charge pipe but found no leaks. He mentioned something about having to do a realtime reading in the exhaust and maybe put back my stock downpipes but looks like i wont be getting my car this weekend....bummer.

[JamesM3M5]

Any tune on your car?

[Monster335]

I use Cobb v401, not tune related though

[GMWNashville]

Possible 02 issue? Did tech do the pressure buildup test plan?

[Monster335]

not sure ill ask...thanks

[Jeffman]

I'm having the same issues. How did this turn out for you?