W210 buzzing on startup - PeachParts Mercedes-Benz Forum

jessie_eaton · #1 01-05-2007, 03:02 PM

I get a buzzing noise for 1-second (or less) on engine startup. Thought it might be coming from the power steering pump but I'm not yet sure. Perhaps it's the oil pump? Seems to happen more often on colder mornings (perhaps a pump is starving when the fluid gets cold/thick)?

Anyone else with a w210 have this problem?

TMAllison · #2 01-05-2007, 04:23 PM

I would describe the PS pump as more of a whine, than a buzz if a little low on fluid.

Mine had a leak at a hose clamp and got a little low and whined making turns when cold.

Something vacuum related maybe?

jessie_eaton · #3 01-05-2007, 04:39 PM

here's a video.

http://www.youtube.com/watch?v=gaM3AmVIXlo

jessie_eaton · #4 01-05-2007, 04:46 PM

buzzing starts 1-second after engine starts and lasts about 0.5 second (for this video)

It's always different - sometimes the noise is immediately at startup and can last a full second

greasybenz · #5 01-05-2007, 04:57 PM

BUMP

to answer your question, it sounds like a slipping belt to me. MY 300SD did the same on start-ups and i later found out it was a slipping belt. They were old weared away belts so i replaced them and they stopped making that buzzing noise.

jessie_eaton · #6 01-05-2007, 05:08 PM

Don't think it's the belt, but I will look into that. Good suggestion.

jessie_eaton · #7 01-05-2007, 05:15 PM

Quote:

Originally Posted by TMAllison

I would describe the PS pump as more of a whine, than a buzz if a little low on fluid.

Mine had a leak at a hose clamp and got a little low and whined making turns when cold.

Something vacuum related maybe?

Vacuum related will be tough to track down. As heard in the video, the noise doesn't last long enough to do much tracking.

I know the whining noise at the PS pump that you speak of. I also had this noise when turning the steering wheel and my fluid was low. The fluid is no longer low. This current noise doesn't correlate to turning the steering wheel.

I only have this noise when starting the engine. I only get the noise on the first start of the day (more noise on cold mornings than warm mornings). Subsequent starts do not make this noise.

Parrot of Doom · #8 01-06-2007, 05:32 PM

Very easy to check if its the belt. When cold, remove the belt and start the engine. No more than a few seconds, and do not let the engine get hot.

If theres no noise, you know its belt related.

jessie_eaton · #9 01-14-2007, 02:43 PM

Thanks for everyone's help. It does appear to be a noise coming from the belt. I half-heartedly spayed on belt dressing and the noise mostly stopped.

This did not sound like the belt squeals I've heard in the past. For future trouble-shooters: The video/audio file picked up the true sound fairly well.