My wife and I were driving our 2000 Volvo S80 the other day, we had decided to turn the radio off for whatever reason and we also didn't have any of the AC/Heater fans going. The windows were rolled up and I was just getting to about 45 mph when we began to hear a slight "ticking" noise from inside the cab of the car on the front passengers side somwhere around the dash area.(I haven't everpin pointed exactly where thetick iscoming from.)

The "tick" was almost the same as a that of a clocks secondhand and it continued while we maintained the speed of 45+ mph. When we slowed down it went away and then would resume as soon as we sped up. I called my service advisor at the dealership and asked him what he thought of it. His theory was that it was possibly part of the environmental control and maybe that a switch or fan was engaging.

My wife has reported to me that she can still hear the ticking if she doesn't have the radio on, and it apparently still happens whether the AC/Heater fans are on or off. The car is running great and I'm not at all concerned, I'm just more curious. Have you guys ever noticed anything like this in your car?

 

Nothing in mine. But if it acts up, I'll take your advice and turn up the radio.LOL

 

Might be the climate dampning motor adjusting for the Fresh air setup in the car.

 

I thought it might be something along this line. I'm assuming that this motor turns itself off and on to adjust the air in the cab?

 

Yes. Try to get it to do it again and see if moving the temp or recirc or the air flow changes the noise or stops it.

 

I'll give that a try.