The car has developed some strange whinning noise and kind of high pitch when it starts in the morning . The noise is only last for less than a minute. This happened right after the morning I changed a set of tires but I do not feel there is any corelation. Dealer told me it should be the second air pump but I do not feel comfortable to spend another $700 before I am convinced what mahes the noise. any input is appreciated.

Definitely sounds like the air injection pump. 99% of the time it only comes on after about 30 seconds or so after a cold start and only lasts for about 30 seconds. It pre-heats the catalytic convertor for reduced emissions on cold driveaways.

Surely you've noticed the pump coming on in the past, so it sounds like for some reason it is making more noise now than it has in the past. If the noise isn't too offensive, you can just live with it. The air pump on our 95 makes more noise than our 98, but it's not a problem.

If it really bothers you, you can get a used one from a recycler.

DEWFPO
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1998 S90 068,300 and 1995 964 152,300

I spent sometime this morning on the noise. Opened the hood, started the car and listened the running of the secondary air pump. It sounded normal to me. Instead the "jet" noise appeared from the front end of the engine block where the belts located. Drove the car 2 mi. for coffee. the noise came on and off but got lounder when I stepped on the gas. All noise disappeared on my way back. The car is 98 S90 with 101,000 mi. Belts were replaced at 70,000 mi. My next move could be let the car sit in the dealership overnight but of course this is the last I want to do.

We had the serpentine idler pulley start to go bad on our 95 960. In the morning we would get a high pitched sound but it wasn't very loud, just noticeable. It would last several minutes and then go away once the engine was warm and not re-appear until the next morning.

If it's a pulley bearing going bad, there are 5 on this engine. Two each on the serp. belt system and the timing belt system plus one on the A/C compressor.

I highly suggest making sure you check the timing belt pulleys. If you can get a mechanics stethoscope (cheap at any auto parts store), you can isolate the sound fairly easily. If it's a timing belt pulley, fix it immediately!

DEWFPO


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1998 S90 068,300 and 1995 964 152,300

Thanks. Will check.

Thanks Dewfpo. It was the timing belt pulley. Got it replaced yesterday along with the belts, water pump...etc. No more nioise this morning.

Thanks for letting us know.

DEWFPO
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1998 S90 068,300 and 1995 964 152,300