Belt chirping

[jmgtp]

I've noticed on a cold start that I get a very faint almost inaudible 'chirp chirp chirp' sound from my accessory belt. Some months back I had a terrible squeal, I chocked that up to coolant that I had spilled on the belt during a waterpump replacement. I tried cleaning it but in the end I replaced it and the squeal went away. Before installing a new belt I used brake cleaner to clean all of the pulleys. Now, I have this faint chirp that disappears after a few minutes run time - the chirp increases with RPM but over 1500 rpm or so I don't hear it - it may be gone but more likely the noise of the motor is covering it up. Once the engine is up to temp it does not chirp at all, under any condition.

I was almost thinking it sounds like a bad bearing in the tensioner or the alternator but when I popped the hood I saw and felt some kind of slimy coating on the belt and the pulleys - not a whole lot, but its there and it shouldn't be. Most notably, I see it on the waterpump pulley, which is smooth and rides on the back of the belt, has some kind of tacky black goo. It could be that I see it there more since that is a smooth/polished surface pulley that it just shows up on more.

I'm fairly certain that this has to be power steering fluid? It's not wet like coolant but just kind of sticky/gooey and black. Strange thing is that the power steering fluid is not low, the timing cover is clean and there are no drips on the ground. The mess is strictly on the belt/pulleys. I'm considering using the power washer (carefully and with a wide angle tip) to clean it all off and then monitor it on a day to day basis to see if I can identify the source. Thoughts?

[robertisaar]

ugh... had to replace the PS pump in the wife's GP about 3 times in a week once.... that threw fluid all over the belt, hood insulator and pretty much everything on that side of the engine bay.

i really wouldn't describe it as tacky and the only reason it ever came out black for me was if it were black in the resivoir, or if i ran the engine and let the movement of the belt scrub all of the fluid off onto a shop towel.

in the colder months, i had to swap a tensioner onto the MC from the 90GP since it failed and caused the power steering pulley to shoot off(bad day). it also did some chirping, but with the warmer weather, i don't notice it at all now.

[jmgtp]

I covered the ecm with a plastic bag and powerwashed the belt and accessories with 1700 psi until they were spotless. then I powerwashed again with the engine running. The belt, pulleys, etc are all completely oil and dirt free. The chirp remains!

And again, after a few minutes of run time it disappears entirely. While it is chirping, if I throw a few drops of water on the belt by the water pump the chirp will stop for a few seconds. So this leads me to believe it is definetly the belt/pulley making the sound and certainly not a bearing in any of the accessories. I've narrowed the sound down (by ear) to the water pump pulley or the a/c compressor (not engaged).

Everything looks lined up correctly and the tensioner is good. If I use a 3/8" breaker bar to apply additional pressure on the tensioner it doesn't effect the chirp. The water pump pulley might possibly have a ding in the running surface. The a/c pulley looks perfect. I'm going to replace the waterpump pulley with a spare that I have to see if it makes any difference.

Other than that I am fresh out of ideas! If it is the belt slipping or rubbing on a pulley I can't explain why it ceases after a few minutes. Perhaps once it gets more heat into it the rubber becomes softer and grabs more? I don't know. It's a weird issue for sure. It hasn't got any worse and is barely audible.

[pocket-rocket]

The last chirp I encountered belonged to a Yukon belonging to some friends. They got a killer deal on it since it was a collision repair. I ended up loaning him my pulley puller/installer kit and he ran the power steering pulley down all the way and the chirp is no longer there. This was the last thing he had to check after replacing the tensioner, tensioner pulley, idler pulley, belt, applying silicone and a bar of hand soap to try to get rid of it. So check your pulley alignment.

[TGP37]

Silly question but, did you replace the belt and/or the tensioner?

Check for a crack in the nipple of the overflow container. Do you hear bubbling after a long drive, shut down?

Is your passanger CV Axle boot cracked (flinging grease around)?

Does the noise get worse when you turn on the headlights (hi beams), radio, blower, brake lights, etc? Try to increase electric load on the alternator and see if any changes occur.

You can also remove the belt and run the car for a few moments to rule out the belt or not. While the belt is removed, see if any pulley is stiff, hard to turn. Sometimes things lock up and force the belt to slip/squeel.


If you are using the expensive leather version belt, try the regular rubber like belt.

[jmgtp]

It's definetly the power steering pump. It got re-gooyed up with oil within a day after I powerwashed it and I can see that the source is def the PS pump which has a nice film of oil on it. Still, it is so odd that it only makes the noise for a few minutes on a cold start then disappears all together till the next cold start.

I purchased a reman pump that will go in this weekend and I'll re-clean it all once more. I'm hoping the pressure washer can save the belt, it got it clean and residue free last time but I wonder if once the oil damage is done the belt is condemned.

[TGP37]

It's definetly the power steering pump. It got re-gooyed up with oil within a day after I powerwashed it and I can see that the source is def the PS pump which has a nice film of oil on it. Still, it is so odd that it only makes the noise for a few minutes on a cold start then disappears all together till the next cold start.

I purchased a reman pump that will go in this weekend and I'll re-clean it all once more. I'm hoping the pressure washer can save the belt, it got it clean and residue free last time but I wonder if once the oil damage is done the belt is condemned.

The belt will never be the same again. It's okay for a little water, oil, etc. but if it got saturated I'de just replace it since it is so cheap. Keep the one you have now as a roadside breakdown backup. A simple belt breaking can be a royal pita at the wrong time in the wrong place.

Replace it especially if PS fluid is anything like brake fluid.

I've have seen an axle boot crack open and slowly fling grease onto a belt. But if the PS pump is saturated, I too would guess that is the problem.

[jmgtp]

Oh man, I wrote this lengthy reply that has apparently not posted.

Short version: The front seal on the old pump was bad, that was my leak onto the belt. I installed the new pump, but now I have a new leak from the backside of the pump. It is not the pressure or return lines (I can see/touch them, they are dry) so I think the leak is the o-ring on the reservoir. I noticed after it runs for even a few minutes if I remove the cap I get a WHOOSH of pressure releasing. The cap is not venting and I think it should be. So, I'm building up all kinds of pressure in the reservoir and pushing fluid past the o-ring. This may have been what doomed my original pump. I'm going to pull the pump once more, clean the new mess up, replace the o-ring and run it again with the cap loose to see if that cures it - in which case I know I need a new cap. Once the leaks are resolved for sure, I'll replace the belt - certainly not before then.

Side note: during the LX9 swap I eliminated the PS cooling loop that runs on the subframe. Can I be overheating the fluid? In the short time I ran it before it started leaking, I'm thinking no stinkin way, but worth a mention. I'm pretty sure there are tons of cars without any kind of PS cooler that don't have issue.

[TGP37]

I really doubt the lack of a cooler would cook the ps fluid that quickly. Have a friend turn the wheel left/right while idling at a higher rpm (spin up the pump more) and carefully see if stuff is leaking. It might only leak under higher loads, making it hard to find alone.

Just don't wear a tie and lean over the serpentine system.......can you believe it happens? Tie gets caught in the belt and slams the guys face into the plenum. And if it didn't break free, the neck would be stopping the engine (hurts just thinking about it).

[jmgtp]

I really doubt the lack of a cooler would cook the ps fluid that quickly. Have a friend turn the wheel left/right while idling at a higher rpm (spin up the pump more) and carefully see if stuff is leaking. It might only leak under higher loads, making it hard to find alone.

Just don't wear a tie and lean over the serpentine system.......can you believe it happens? Tie gets caught in the belt and slams the guys face into the plenum. And if it didn't break free, the neck would be stopping the engine (hurts just thinking about it).

It leaks under no load, even when the engine is off for about 5 minutes - I presume because the reservoir remains pressurized for some time. More I think about it, the more the cap seems to be the problem. I tend not to work on my car while wearing a tie! Lol. But I did tuck in the drawstrings of my hoody yesterday while I was working on it

Thanks for the input and I'll follow up with the end result. I need it to run ASAP because I can't afford to drive the Dakota on $4 gas.
Side note, the LX9 acheived 22mpg on its last tank, which was equal shares cty/hwy and that included a few WOT runs for tuning purposes. After it passes emissions I'd like to enable lean cruise and see what it can do.