Light clicking noise at equal interval when AC is engaged

automatic_kyle · Post by **automatic_kyle** » 02 Sep 2011, 13:50

Hey everyone,

I am new to this forum and new to the Volvo world. I just purchased last week a nice S40 2007 with 40,000 miles on it. I have a small clicking noise that I just noticed coming from the dash area when the AC is engaged and the car is moving. The sound will disappear when idle sitting at a stop and/or if I disengage the AC. I am not that mechanically inclined with cars, but would really appreciate your input. When the sound is noticeable it clicks every 5 to 7 seconds and stays at this interval.

Thanks!

Post by **fazool** » 06 Sep 2011, 20:54

Not sure but it sounds like it MIGHT be the AC clutch. Its an electro magnetic clutch that engages to "grab" the belt and power the AC unit. It turns on and off depending upon temperatures, refrigerant pressures, etc.

If it is that and it is cycling on and off you might have a strangeness in your AC system (one of the sensors)

Does AC work continuously?

automatic_kyle · Post by **automatic_kyle** » 15 Sep 2011, 18:00

I haven't notice any change in the AC. Seems to work completely normal. To update now it happens when sitting at idle too. The only way it stops if I cut off the recirculation.

meganS40 · Post by **meganS40** » 25 Aug 2014, 06:08

Would you be able to update me on what you did to fix this issue? I have a 2008 s40 with 118k miles and it is having the same issue.

Thanks!

shanegtr · Post by **shanegtr** » 29 Aug 2014, 17:57

I'm not familiar with the 07 models, but on my 99 I had a faulty servo motor. However that created a click around twice every second and only lasted about 2-3 seconds and was only intermittent. Turned out it was a missing tooth I the servo at the end of its limit and the click was the motor trying to drive over the missing tooth. You might have something like this happen?