Noise after fluid changes! - PROBLEM SOLVED

[Snowbeast]

What have I done!?

I changed my oil, tranny fluid, and all four o2 sensors today. No problems, very easy when following procedures on the board. Now, my car makes this strange humming that syncs with the engine RPMs. I can be a little loud in the car, doesn't sound too loud from out side the car.

I used BMW 5-30, 7 quarts, new filter, no overfill. 2 quarts of Royal purple synchromax, and OEM bosch o2 sensors. The car was perfect before, I am just a proactive kind of guy so I thought I would do it.

This new noise is making me crazy! The car seems to drive fine. Seems to have the same power just sort of hums when the RPMs are up, most noticeable at 2000 RPMs.

I have double checked oil and tranny fluid levels - they seem to be perfect.

Any ideas? Did I ruin something? Should I be worried?

[ard]

Check your exhaust alignment. Could have tweaked it and you are getting a vibration from that...

[jaj]

Check to see if you dropped a tool or a piece of trim down in the engine bay - it could be rubbing against a pulley on the front of the engine. From what you've said, chances that you damaged something are very remote.

[Snowbeast]

As you all probably know, the oil filter housing is fastened to the car with some wimpy rubber mounts. If the person changing the filter before you was an idiot and put the filter housing cap on too tightly, you need a wrench to remove it. This is what happened to me.

So, the rubber mounts broke when I wrenched the cap off. It seemed like a bad idea to let the oil filter just rattle around in there, so I drilled out one of the mounts and put nice strong bolt in there with a few washers.

Well, now I know that BMW made that thing rubber mounted for a reason. Apparently, the oil filter and housing generate some serious vibration and noise. Hook that to your car body firmly with a bolt and you get the scary new noise I heard while driving. It resonates loudly in sync with the RPMs right through your dash.

So, I unbolted my mess, replaced it with a zip tie and some rubber pad until I get the new mounts - and the noise is gone.

It is amazing to me that the oil filter would generate so much noise and vibration. Believe me, it does. Bolting it firmly is not a good idea.

There is a nice thread about these mounts with a part number on search.

But I think I might be the first one to have really secured it and gotton noise as a result.

Thanks to those who chimed in with ideas.

[ECB]

Nice detective work. I use a strap wrench to stabilize the oil filter housing while I tighten/loosen the cap. And yes, not much torque on tightening.