2002 S60 (non-T) w/155K miles, engine is squeaking

[Ru4Wheel]

In the last week my car has started to squeak. Once it warms up mostly and when the A/C kicks in. It's mostly quiet with the A/C off. Any ideas? Is it simply a snake belt? Thanks.

[jimmy57]

Pull the dipstick out with it running and see if it stops squeaking. If it does then the crankcase vent box with integrated crankcase pressure regulator needs to be changed.

If the dipstick thing makes no difference then remove serpentine belt and inspect the tensioner roller and the alternator to see if either of those will squeak when spun.

Last thing is water pump or timing belt tensioner but those are much less likely as A/C being on would not impact those parts.

[abscate]

You can usually isolate where a sound comes from with a piece of plastic tube used like a stethoscope.

Garden hose or Tygon. Listen to each moving component. You can actually hear the separate beatrng noises in your alternator, front and back if you practice a bit.

Don't scare any children doing this