EngineeredTech

I've searched all over the internet and cannot find any leads on my issue.

I've got a 2013 GLK RWD with 105,000 miles on the M276 Engine and I have a loud whining / squeaking noise coming from the top front of the engine.(Best I can tell without a Stethoscope is that it's coming from around, behind, or just under the Throttle Body) The noise happens at idle up to about 4K RPM. I removed the Serpentine Belt and ran the engine and the noise WAS STILL PRESENT. The Check Engine Light came on around the same time we first started to notice the sound. I pulled the following codes, though these could very well not be related:

P061B - Internal Control Module Torque Calc Performance
P2279 - Intake Air System Leak

Now for some background info. I used to be Certified BMW tech about 6 years ago while I was going to college for engineering and I know my way around an engine and I assure you I've ruled out all the obvious/common whining issues. The noise changes pitch with RPM, however it is not noticeable/goes away under WOT and at high RPM (above appr. 4K). The noise doesn't start (normally but not always) until the engine gets warm. It starts off quietly and then gets progressively louder over the period of about 1 minute after the engine gets warm. The engine runs normally with full power however the wife did have an issue only once with a reduced power mode while in a parking lot that she described as the engine running rough and the traction control system disabled light/ message came on. She parked it and restarted it a few minutes later and everything was back to normal except for the noise. (The performance issue could be the result of the air intake leak which I'm getting a leak test performed tomorrow)

Anyways, like most people I initially assumed the noise was from the belt given that its the factory belt with 105,000 miles on it. The belt had a split in it anyways so I put a new belt on but the noise didn't go away. So I started looking at/testing the pulleys. After various testing I began to think that the problem wasn't related to the belt system so I removed the belt and ran the engine and the noise was still there. I had seen a few posts discussing various issues with the intake flap however best I can find the flaps are on the back of the intake but the noise is definitely coming from the front. I'm not sure an Idle air valve would cause this type of issue either. I'm becoming increasingly worried that this noise is coming from the timing chain system. The noise literally popped up over night about a week ago and it doesn't appear to be getting any worse or louder.

Has anyone out there ran into this issue before? Are there any known issues/problem parts with the M276 motor that could be causing this. I can use all the help I can get at this point.

dlinegar

Had a similar issue. Ours was only on cold-start and would last exactly 1 minute from start-up. Turned out to be the Air Injection Pump, part of the emission system. The relay and pump had to be replaced, bearing went bad. Part Number: 000-140-51-85 and 002-542-87-19. Parts are stinking expensive, be warned...

--d

Acuero

Acuero

Joshua Mast

Did you ever determine the cause of your symptoms? I have a 2012 r350 with the m276 engine that has identical symptoms and codes. Thanks!