[daMau]

2007 335i, 70k miles

My 335i has started making a grinding/clicking noise, emanating around the oil filter housing/alternator, but I am having a hard time pinning it down. It is more frequent and louder when the AC is turned on.

Because the noise changes when the AC is turned on, I am thinking it is either the AC compressor making noise, or the alternator due to the extra draw when the AC is turned on.

I have a video below. The radiator fan is blowing, so it is a little loud, but you can hear the noise in the background. The engine is otherwise sound and runs very well.

Anyone experience this before?

[5tony]

Have this same noise coming from the area of the alternator. Anyone have any idea of what it might be?

[turbohugh]

Originally Posted by 5tony

Have this same noise coming from the area of the alternator. Anyone have any idea of what it might be?

Put your car up on some Rhino Ramps.
Pull off the undercovers
Carefully inspect the power steering pulley [rear of pulley] and belt.
Start the car and let it idle.
You will have to remove the air-snorkel
You can use a very long screwdriver as a stethescope and 'carefully' place it on the alternator, then the powersteering pump [from below].

It's probably the tensioner or / and the idler pulleys. I'd suggest getting the replacement kit from somewhere like FCP Euro. Comes with a nice continental belt and be sure to order a replacement PS Pump Pulley.

I've heard of the alternator bearing going bad in E39 M5's resulting in the grinding noise. I haven't personally experienced this with the E90s, however you can put a very long screwdriver on it and hold the handle end to your ear to see if the bearing is making the noise. [or get a harbor freight stethescope].

[5tony]

Originally Posted by turbohugh

Put your car up on some Rhino Ramps.
Pull off the undercovers
Carefully inspect the power steering pulley [rear of pulley] and belt.
Start the car and let it idle.
You will have to remove the air-snorkel
You can use a very long screwdriver as a stethescope and 'carefully' place it on the alternator, then the powersteering pump [from below].

It's probably the tensioner or / and the idler pulleys. I'd suggest getting the replacement kit from somewhere like FCP Euro. Comes with a nice continental belt and be sure to order a replacement PS Pump Pulley.

I've heard of the alternator bearing going bad in E39 M5's resulting in the grinding noise. I haven't personally experienced this with the E90s, however you can put a very long screwdriver on it and hold the handle end to your ear to see if the bearing is making the noise. [or get a harbor freight stethescope].

Thanks! I'll check all that out. Will probably go ahead and replace the tensioner, idler pulley, and PS pulley to start with.

[turbohugh]

Once you take that air funnel off let it run and look at the belts. have someone turn the steering wheel and watch the tensioner.
Then try the stethescope trick.
You may be able to figure it out from the top, but I'd check underneath also just to be sure. That powersteering pulley eat your belt and you can be looking at ingesting the front main seal .. big $$$$$