98 S70 T5 chirping noise

Keshavsmith · Post by **Keshavsmith** » 12 Jun 2023, 18:25

Hey guys. Like the title says, I’ve got a chirping noise happening. It happens the entire time the car is on, whether idling or driving. I’m guessing it’s a belt of some type… the guy I bought it from had the timing belt done a few years ago, but I don’t know the mileage it was at. Is it ok for me to be driving with this noise? I’m obviously planning on getting it checked out, but for the immediate future, I have places I need to go…
Thank you for any input you might have!

Post by **scot850** » 12 Jun 2023, 19:05

Are you able to record it and post it for us? Ideally if you can isolate an area of the engine bay where it is coming from it will help us to help you.

Neil.

jmartin919 · Post by **jmartin919** » 12 Jun 2023, 19:14

I may have the same thing on my 93 850. Started soon after I changed the timing belt. If I "condition" the outside of the belt with some Aeroapace 303 vinyl protectant it will go away for awhile. I think it's the belt rubbing on the idler pulley - the belt kind of walks back and forth just enough to chirp. I've put about 25k miles on the belt.

yanga001 · Post by **yanga001** » 12 Jun 2023, 20:04

Likely the auxiliary or serpentine belt. The idler pulley bearing may have gone "bad" so it will be very noisy for a while.

This is a 2 step process as well. If its from the timing area then that is more concerning as the tensioner pulley or other sections may have their bearings going bad.

Step 1: remove the serpentine belt and start the car. You will only run it briefly as there is no alternator to charge the battery and no power steering.

If the sound is still their then it is likely in the timing area. On the older cars it can come from the water pump or tensioner pulley i believe. I say this as bearing slips/screeches are more characteristic of what you are describing and are present in the waterpump and idler i believe.

If the sound is gone then congratulations, its somewhere in the accessory area.

Step 2:

Get a mechanics stethescope or use a screwdriver trick to check the amount of noise coming from the alternator, power steering pump, and idler pulley. Try to rotate the idler pulley with the belt off. If it is loose, easy to spin, and wobbles a bit then i would recommend changing the pulley. If my memory serves me correctly it can be changed by taking out the power steering pump and associated bracketry. You may be able to change it in the car by undoing the retaining bolt but i do not recall.

If its not the pulley then it could be the alternator or power steering pump. Separate checks for these.

The noise in this case comes from friction as the bearings wobble while spinning i believe.

Post by **abscate** » 13 Jun 2023, 03:00

A short piece of hose in you ear works even better as a stethoscope. You will hear a lot of noises that sound bad even on a good running part, so don’t freak. Lot of whirring from the alternator is normal. If you kind of listen from both ears you can correlate the hose noise to the squeak noise. Probably in the accessory train, not the timing train

Keshavsmith · Post by **Keshavsmith** » 13 Jun 2023, 14:32

scot850 wrote: ↑12 Jun 2023, 19:05 Are you able to record it and post it for us? Ideally if you can isolate an area of the engine bay where it is coming from it will help us to help you.

Neil.

I will do that here shortly. Thank you!