Weird noise!! me and my luck!!
 

When I have the AC or Heater on ....right before I come to a complete stop at a light....I hear a rattle...which fades away as soon as I stop.

My tensioner shock was replaced 2 weeks ago....because the previous one was defective and came lose. Ever since that problem I have not had to use AC or Heater because of the Beautifull weather here in Cali...but yesterday with the heater on I can hear it.

This sound only comes up when AC/Heater is on.....However, when the system is on economic mode or off there is no rattle.

Again mind you that I can only hear as I come to a stop...

Any suggestions as to what the problem might be?

Could the lose shock have damaged my tensioner......which only rattle when it is under the stress of the working AC/Heater.

Or is this purely an Air condition type of problem. Blower, ....etc.

PLEASE HELP IS APPRECIATED

thanks

oh by the way my car is a 1996 C220

C class compressor knock. Mostly on M111's.



In other words the a/c compressor is going away, I've heard a few that were knocking that ran for a long time before failing.


Joe

and this "knock" you are talking about Joe P.....would it be a constant one, or intermittent.

I can only hear it as I come to stop.....it rattles ...then when I stop it goes away.

I have left the car idling for 20 minutes....with the A/C on and could not get it to rattle. Only in the above mentioned senario.

by the way my A/C is woring perfectly....actually everyone compliments how cold it gets when they ride with me .


I don't know anymore!!

someone suggested to me that this noise..might be a bad A/C compressor clutch.

Could that be true ......and does my car have an A/C compressor clutch

???