1997 C280 ... There is a strange noise coming from behind the dash .... sounds like a kinked Speedo cable it gets louder as you go faster ... it comes from the center of the dash behind the two vents I took the drivers side panel down but there isn't a Speedo cable has any one run across this problem.. and does any one where I can get the tools to remove the radio and heater control panel.

 

Is it a mechanical noise of an electrically noise, there is a difference, a mechanicle noise would sound like something is spinning or scraping, a electrical noise would be clicks, for the most part. I would get a set of pod pullers, and remove the cluster and see what is going on. they can be bought off eBay cheaply and have, in my case come in handy, both on my 99 C280 and my 79 4450SLC, which is also a press, spring loaded fit.

 

Is it a mechanical noise ! Sounds like a bent spedo cable. Gets louder and faster as the car goes faster and slows down as the car slows down. I pulled the center Heat control and glove box then gave it a road test the noise didn't change I still could not pinpoint where it is coming from. Does the spedo or trans run by cable and how do you gat at it. I used a paper clip to remove the heat control but it would not work on the radio. I took the under part of the dash down but didn't see a spedo cable ???? Any help is appricated Thanks

 

speedo cable was only use on models 10 years back from yours.

could the noise be coming from somewhere else and just transmitted to such location?

 

couldn't it be the refrigirant pipe line?

 

i think "mywife" is describing the noise of the cabin temperature sensor's ever-turning fan..

 

The noise seems to be directly related to the forward motion of the car. The noise is like a paper card in the spokes of a bicycle the faster you peddle the louder and faster the noise gets. When the car is not in motion you don't hear anything and now with the new plugs , wires, and coils it is smooth and has great response. There is just this noise coming from what seems to be right behind the two center air vents dead center of the dash ???

 

Can you hear the noise if the car is stopped and you rev the engine?

 

Can you hear the noise if the car is stopped and you rev the engine?


No you can Idle or punch it and no noise or vibration thats why I thought it was a spedo cable and not a tack cable problem. When the spedo starts to move the noise starts the faster you go the faster the noise. Sounds almost like a plastic tie strap in a fan the faster the fan turns the faster the noise gets ???? It's got me pulling my hair out. How does the insturment panel come out ?

 

Have a good look at the firewall for missing grommets. But this would change tone with a change in gear. Perhaps you have a noise in your transmission or driveshaft . See if you can get your mechanic to put the car up on a hoist and put it in gear and replicate the noise.

Like Sleepwalker said, there is no speedo cable. The car uses an electronic signal up to the speedo.