The Unofficial BMW M5 Messageboard (m5board.com) - View Single Post - Noise after fluid changes!

Snowbeast · 5th August 2007, 06:49

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?

5th August 2007, 06:49	#1 (permalink)
Snowbeast Member, Sport: Off DSC: On (>50 posts) Join Date: Jul 2007 Location: Utah, USA Posts: 89 Thanks: 28 Thanked 8 Times in 6 Posts	Noise after fluid changes! - PROBLEM SOLVED 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? Last edited by Snowbeast; 6th August 2007 at 02:37.