alexzxn

Hey Guys

I have a 2006 525I N52 3.0 engine about 110k miles

A while ago my CEL came on and I scanned it is P0171 & P0174 or 2A2E & 2A2F since it would only happen when its super cold out so i did some research narrowed it down to the Vapor Canister Purge Valve so i bought a new one and changed it.
The CEL came back up 50 miles after i left the garage
The car runs fine but the CEL would always be on (I didn't drive it a lot 1000 miles top) so I kept looking for solutions. Last week the condition got worst now I've got this weird Whirring noise when i rev the engine above 1000 RPM and the whole car shakes a bit (feels like the engine is a bit off balanced) from 1000 RPM to 3500/4000 RPM.
There is a major delay when i try to rev the engine and when i rev it up to around 1200RPM the electronic threttle body control unit would try to adjust the RPM back to 800 above 2000 RPM it wont try to adjust.
Now I have this new code P0012.

I know the above symptoms shows i have a big vacuum leak but i did the smoke test the whole system seem to be sealed pretty well.

I have changed both the VANOS solenoids; cleaned and swapped the camshaft position sensor no luck.
I also changed the Oil Separator Valve and the Crankcase Vent Hose last year less than 10,000 miles ago.
All new spark plugs installed 1 year and half ago.
I do not have DISA on my engine since its the de-tuned N52 3.0L.

Any idea whats wrong with my car what should i do?
Your input will be greatly appreciated.

Thank you in advance.

Alex

E60I

Clean the MAF sensor and see if that would make a difference.

alexzxn

Already cleaned the MAF sensor didn't make a difference.
Appreciate your help tho

pcy

Alexzn, you really researched and have gone thru the usual suspects....

Possibly, there is leak in intake. Look closely at the intake tubing between MAF and throttlebody or at the intake manifold connections. Unmetered air can cause issues.

Try this: Disconnect MAF and run the engine, does the engine run better?

alexzxn

Hi pcy
you helped me with my Vapor Canister Purge Valve installation thanks a lot.

I've tried to disconnect the MAF didnt really make a difference.

DennisM

P0171 - P0174 Lean Bank1 & Bank2 maybe it could be o2 sensors or try to clean Idle Control Valve

FaintReality

When it throws a P0171 & P0174 code at the same time, it's usually a leak of the intake, most likely a hole/tear in the boot. My dad had the same issue with his 3 series last week. Even though it looked fine, I told him to remove and inspect thoroughly. Sure enough, there was tears in the accordion style grooves of the boot.

ranger530i

I have the same issue... same codes too! How much did it cost him to repair the issue?

FaintReality

Just had to buy a new boot which was $30 locally. They can be found for around $20-$25 online. It's a fairly cheap easy fix.

ranger530i

Did you have to get the SES light cleared or did it go away on its own?