Annoying squeal

[mjmcg]

2011 5.7. New idler, new tensioner, new belt, new alternator... still have an annoying bearing squeal that doesn't go away until well after operating temp and some miles each day.
Water pump? PS bearing? I can't zero in on it to save my ****.
With over 100k on her it probably wouldn't hurt to change the wp, but I hate changing parts that aren't bad to chase down noises.
Already just did that with the alt. By the time I'm done I could have swapped everything on the belt out and still not found it.

 

[Dean2]

Get one of the 20 dollar stethoscopes off amazon. You will isolate the source a lot faster with it than changing parts. Even a real long piece of threaded rod, long screwdriver or extension will work. Move it from potential source to source put rod to ear. BE VERY CAREFUL as the engine is running and stuff is moving. Let us know what you find.

how to use engine stethescope at DuckDuckGo

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[BenchTest]

+1 on steth. Great tool that is under-utilized.

 

[RamDiver]

A stethoscope is another must-have tool, especially for older trucks.

For a quick fix, if you don't have one available, any steel rod, post, etc will work.

For those tough-to-get-at locations near moving parts, where you want your face far away, find a large screwdriver, and duct tape the handle into the opening of a plastic pop bottle with the bottom cut off.

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[BenchTest]

A stethoscope is another must-have tool, especially for older trucks.

For a quick fix, if you don't have one available, any steel rod, post, etc will work.

For those tough-to-get-at locations near moving parts, where you want your face far away, find a large screwdriver, and duct tape the handle into the opening of a plastic pop bottle with the bottom cut off.

.

But, it has to be a Dr. Pepper bottle, because...doctor

 

[RamDiver]

But, it has to be a Dr. Pepper bottle, because...doctor

If that is your preference, I'm a fan of Dr. Pepper too.

This technique is remarkably effective, just like a stethoscope but loud enough for anyone in attendance.

.

 

[mjmcg]

Agreed, I've known about scoping things for years. Surprising how you can locate stuff. Unfortunately I've already taken that approach using both a long screwdriver and breaker bar.
What I discovered was that I could hear the rumbling of the units I was poking around on but the squealing is too high pitched to transmit through the tool to hear. I can hear the rotation of the parts loud and clear as you expect, but that squeal is only audible ambiently. It sounds just like moisture on an idler pulley until it dries, like morning dew.
If they ever deliver the water pump I'll swap that out just on principle and go from there.

 

[GTyankee]

there is way to check the water pump bearing

When the engine is cold, as in shut off for several hours, or with the Negative battery post disconnected.
put your fingers directly under the water pump, there is a small hole under the bottom center of the pump.
If you feel wetness, your water pump seal is leaking.
If drive much more, the seal will leak more & at any time the water pump could seize up.

Personally, i either use a Wood Dowel or a cut off Broom Handle as a Stethescope. I also have a HF automotive stethescope

 

[Dean2]

Agreed, I've known about scoping things for years. Surprising how you can locate stuff. Unfortunately I've already taken that approach using both a long screwdriver and breaker bar.
What I discovered was that I could hear the rumbling of the units I was poking around on but the squealing is too high pitched to transmit through the tool to hear. I can hear the rotation of the parts loud and clear as you expect, but that squeal is only audible ambiently. It sounds just like moisture on an idler pulley until it dries, like morning dew.
If they ever deliver the water pump I'll swap that out just on principle and go from there.

If you can't hear the squeal through the scope you have not located the source. If a noise is being made by a bearing or whatever, it is impossible for it not to be picked up by the stethoscope once you get it on the right item.

 

[RamDiver]

If you can't hear the squeal through the scope you have not located the source. If a noise is being made by a bearing or whatever, it is impossible for it not to be picked up by the stethoscope once you get it on the right item.

If he's using a proper mechanic's stethoscope.

Sometimes pressing a screwdriver handle to your ear may lose some of the higher frequencies due to marginal audio conductance from the handle to your ear.

If the OP doesn't own a proper stethoscope, this is an $8 investment that is much better than faking it with a screwdriver. It has a much better sensitivity that can't be matched with using other tools.

Mechanics Stethoscope

Amazing deals on this Mechanics Stethoscope at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

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[Tach_tech]

Have you ran it with the belt off to make sure the noise is coming from the accessory drive?

 

[Atcer2018]

Have you ran it with the belt off to make sure the noise is coming from the accessory drive?

^^^^what he said

 

[GTyankee]

Draw out a sketch of how the belt runs over & around the pulleys

I have cussed out my own foolishness a time or two, while trying to replace a serpentine belt

 

[Dean2]

Draw out a sketch of how the belt runs over & around the pulleys

I have cussed out my own foolishness a time or two, while trying to replace a serpentine belt

You have a camera on your phone. Easy way to solve that problem.

 

[StateOfMind]

My annoying squeal stopped right after I dropped my kids off. YMMV

 

[mjmcg]

Have you ran it with the belt off to make sure the noise is coming from the accessory drive?

Oddly, you were the closest to the solution.
I had said screw it and replaced the alternator already because the original alt did in fact make noise when spun by hand but that was not the source of the running squeal. So, I bought a new water pump and upon beginning the task of changing it I followed my own rule and closely examined every piece I touched along the way, starting with the belt. Since I'd already switched the idler pulleys around I took a close look at the month old belt I'd just put on and I observed shiny patches in the bottoms of some of the grooves. They alternated and were of varying length. None of which gave me cause to believe they could cause any issue but nonetheless I grabbed the previous belt, wrapped it around the hoops and started it up. Much to my curious bewilderment the squeal was gone altogether.
Now mind you it wasn't a constant squeal but a chirp chirp chirp chirp chirp type thing.
I have no clue, but that's why scoping for it yielded no results. For some reason it was the belt all along.

 

[EdGs]

Good catch!