I noticed when my AC is running that my car almost stalls everytime the compressor cycles. Basically I can hear the compressor cycle and when it releases the rpms pull down about 300. The engine adjusts by adding more rpm for a second then it goes back to normal. I understand that the AC will pull from the engine and the computer should adjust for the fluctuation but it pulls down low enough (<1 second) to shake the car a you can feel almost cut off before catching back up. My car is an 01 2.4T with 123K miles.

Any ideas?

Thanks for the help!

 

Sorry about the problem.

As you have described, the idle boost system may be having a minor problem. Since I am not privy to the S60s, I would visit an independent shop that specialises in Swedish.European makes (make sure that theyhave "ASE-CERTIFIED" poster outside/inside the shop). Or, visit a dealer and tell them exactly what want them to do (e.g., "The idle boost system seems to be allowing the RPM to drop excessively when the A/C is on so please check the cause-and please don't try to sell me a new compressor because my car doesn't need one[8D]")

If you're handy with tools and have good knowledge, I would consider getting a service manual too.

And see if other S60 owners reply to your question.

I wish I could help you better.


JPN

 

I actually ended up posting the question on swedespeed & volvospeed and got a few options. It appears that it may be the ETM on it's way out. I cleaned the MAF and that didn't help anything (although it was good to do anyway). After looking at the problem a little closer, the idle actually drop too low when coming to a stop but quickly catches up. This occurs with the AC on and off BUT it is worse when the AC is on. I don't think it is the compressor at this point because of the other symptoms. It appears it may be a ETM problem (I have an 2001 and we all know about the ETM problems[:@]) or PCV concern.

I do most of the work on my Volvo (and my other vehicles) but it appears this one may have to be diagnosed at the dealer. Then I will decide if its worth fixing myself or paying for the labor. I wish the S60 had a "normal" repair manual like the previous Volvo's (to bad Volvo's have changed so much )

Thanks for all the help

 

Try cleaning the throttle body first before taking it anywhere.
Sorry would have replied earlier but have been really sick.