My '98 XC makes a strange noise in the engine compartment when starting. It's almost a honking sound, and lasts about a minute. As the sound diminishes, its pitch increases until it's totally gone. Sounds like something "spooling-up". Serp. belt has been changed, and there are no obvious problems with pulleys or idlers. P/S fluid has been replaced with Mobil 1 ATF. I wonder if the P/S pump is sucking air through a bad seal on the steering rack?

Thanks!

My hearing is not as good as yours, probably because I am 480 miles NW of you.

It could even be the air pump with a leaky hose? Please open the hood, even determining the side of the car would help. A PS coupling sucking air would also be big enough for a massive leak.

Klaus
--
Always willing to listen, just not able to take direction.

No obvious loss of P/S fluid, so if a leak exists it is minimal.

Noise seems to come from P/S pump & alternator area. I had local Volvo mechanic listen, and he thought it might be from under the cam belt cover.
I removed this cover and checked for loose idlers, rubbing cover, etc. with no luck. Started engine w/o cover, and noise did not appear to emanate from timing belt area.

Does a '98 XC have an air pump? Where is it located?

Thanks!

Air pump is in front of the driver side wheel, so that is not it.

Use a dowl rod or other suitable long stick, one end against your skull by your ear and the other end touching the alternator or PS. That is a mechanic's stethescope that will pinpoint the source of the vibration. Don't forget to touch the thermostat housing, if the thermostat doesn't close properly it could also vibrate.

Klaus
--
Always willing to listen, just not able to take direction.

I tried this before with a long screwdriver, but couldn't pinpoint the noise.

The thermostat possiblity is very interesting because the sound actually begins about 10 seconds AFTER starting the engine, and continues to increase in pitch until it goes away. What type of noise would a vibrating thermostat make?

Thanks!!

Just guessing. The thermostat is in the same general area.

Klaus
--
Always willing to listen, just not able to take direction.