Hi,

I have C200, and the other day whilst turning on my heater dial a strange noise appeared from what seemed to be behind the middle of the dash board. The noise was rather like a motor sound. The noise was not audible when I turend on the heater to full blast, but only on the lower settings than that. However the sound is not there now. I will add that we have been having some fairly cold weather here in the UK. Is it a probler with my heater blower motor?

Ta

 

Blower motor or vacuum leak. If you have have the ability to get up under the dash spray some WD40 on the bearing inside the blower, the blowers is usually round and has holes on either end, spray the WD40 directly into the center. A vacuum leak is a bit more complicated, I bought a vacuum guage, the hand pump type, $10US, but you need to find where the source of the vacuum is in order to attached the pump and then follow the line to the heater controls or whereeven it they lead to see where the leak is. there are dyes U can buy to help see the leak.

 

Thanks Allan,

Would a leak mean that there is visble liquid inside the car under the dash and on the car floor?

 

the vacuum isn't liquid and very much invisible.