W124 (300E) Buzzing from Dash
 

Getting an intermittant buzzing/high frequency noise from dash on start-up - sometimes it stops but sometimes it just keeps on buzzing.

Anyone had the problem? it is driving me insane

Maybe some bees in there? LOL :D Just kidding - I could not resist.

Seriously, it sounds like a relay or something sticking. Does it seem to change with the outside temperatures? Does everything on your instrument panel seem to be in proper working order, even with the buzzing?

Sounds more like a bunch of hornets!

The rev-counter is not working but everything else is fine. The sound is the result of something sensitive as it stops if I hit a road bump.

Should also mention that I think the OVP relay is playing up as I get occassional stall at idle or deacceleration. I'm having that checked - maybe related!

From over near the glovebox??? All the way to the right?
Gilly

Hi Gilly, Dead right - screams away on most start-up's and sometimes stops, bump etc, but not always. Jim

Over to the right of the glove box (I know not much room inside the dash there) there is a small suction fan which draws air through a tube which runs up the right windshield post, to the dome light, through that small slotted square hole in the dome light, which draws air through the incar temp sensor. Over-engineering at it's best. The fan needs to either be replaced or you can take it out, try to clean and lube it up. I think the noise might go away if you try shutting off the climate control, if you want to see if that affects it.
Gilly

OH you're an Aussie, not sure what side your steering wheel is on there. If it's from the glove box area I'm pretty sure this motor is what it is. This also assumes you have automatic climate control.
Gilly

Check your fuses especially the instrument cluster one, take it out, look at it closely, then put it back, or if burnt, replace. I believe it's a red one.

RHD Gilly and I don't have ACC but I think there is a fan in there anyway - does the dash need to be pulled or you reckon it can be got at from under? Jim

From under, or if it IS next to the glove box you can just remove the "box" and get to it. I would think just automatic climate control cars would have the in-car temp sensor, hmmmm.
Gilly

I get the same thing at start up but it always goes away. Mine comes from the left side dash. Weird!

Mine does the occasional buzz sometimes almost a scream when the ignition is turned on but goes away completely after the engine has started. Mine comes from the RH side of the dash as my car is RHD. I'm convinced the noise comes from the small electric water pump inside the bulkhead behind the engine, I think it feeds the heater but is always running. The water may drain out on standing and it runs dry until the engine water pump gives it a charge.

You can check the small fan supplying air to the temp sensor in the interior light cluster by turning on the ignition and putting you ear to the glove box, you can just perceive a faint hum if all is working as it shoulb be - you can't hear it when the engine is on.

Likewise - down under in Oz we are RHD vehicles

Thanks - that's worth checking out, however, in regard to the fan, are you referring to the climate control set-up as I don't have it.