Wth is causing this squeal?

Monkeynono said:
Can you run the motor without the trans? I have run in to this noise and it was the converter bolts hitting. But if your not seeing and metal shavings or marks?
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That's what I was wondering.
I fixed quite a few 4.0 rod knocks by tightening the converter bolts back up.
Any chance of bolt head interferance?
 
Croatan_Kid said:
But is the pilot on the converter sliding in to the crankshaft like it should?

If you would, take a picture of the back of the motor. I'd like to see the flexplate and the crankshaft hub. This way, I can figure out if there's any issue with long crank/short crank alignment. If we eliminate that, then we can diagnose further.

Unless you or the previous owner know what the motor and transmission came out of originally and if they were a mated pair.
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The crank pilot bore is clean with zero damage. I can see a line where the tc sits, maybe 3/16" in. No rubbing shows.

No rubbing by bolt heads either. There is no sign of that, plus, there's a ton of room for bolt heads with this flex plate.

Starter is retracting like it should.
 

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Pull the converter and look at the input shaft bushing seat. If the converter was cocked during the Bluetooth cranking it could have scored that area
 
Small update for the evening.

The converter fits well in the back of the crank. It slips in a good bit, hard to know how far, but enough. Crank bore looks great. It still did have a small burr on one side.

The od on the converter has a weird swirl that's not even. The chatter that shows is a reflection in the video.

A transmission guy i know said to make an adapter to spin the converter. I looped the cooler lines already and will make something tomorrow at work for that. We'll see if that makes any noise.



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Those chatter marks would be right about where the pump rotor sits around the converter stub. The black looking rub mark would likely be the front pump seal.

The squeal could be the rotor and vanes spinning inside the pump ring, but they'd have to be dry...I.E.- the pump aint pumping. That'd suck, but it isn't terribly hard to fix/replace since it's at the very front of the transmission.

Both of the forward-most bushings that the input shaft rides in are also in the pump stator shaft.

The other issue could be IN the converter. The stator and turbine have needle roller thrust bearings between them.


However, before you tear anything apart, put the starter back on, fire it up, and see if it's still squealing. That will be a big clue either way it works out and won't cost you anything.
 
Croatan_Kid said:
However, before you tear anything apart, put the starter back on, fire it up, and see if it's still squealing. That will be a big clue either way it works out and won't cost you anything.
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Already did. I plan to run it longer though.

 
Hmm...sounds quiet as a church mouse without the transmission spinning 😬
 
Well shit. I mentioned running it longer since I only ran it a min the first time. I pulled the flex plate and I don't see anything external. It looks like it had never been removed.

Aaaand, the starter isn't touching.


 
Shreddinlettuce said:
Spray carb cleaner around the vacuum lines while it’s running, if it stumbles wherever you are spraying is the location of the leak if there is one also spray around the base of the intake
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I did that already. I just ran a propane torch around a minute ago. Nothing. I'm gonna borrow a smoke machine. Then idk what.
 
With it running and making the noise, pull the oil cap off and see if it stops. If it does, there's some PCV hoses routed incorrectly. Wouldn't show as a vacuum leak, but it'll put a helluva lot of vacuum in the crankcase and find the easiest seal to pull air past. That'll make some weird noises.

If it doesn't...it's something else!

You could pull the rear main seal cover and put your eyes on the rear-most cam bearing, if it comes to that. I could see where, possibly, one of those could rotate, cut off oil flow to a cam journal, and make some noise.
 
Shreddinlettuce said:
Crank bearing, cam bearing, water pump not shimmed properly, have you done the screw driver stethoscope test yet?
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Nope, just went around with a hose to my ear putting it places
Croatan_Kid said:
With it running and making the noise, pull the oil cap off and see if it stops. If it does, there's some PCV hoses routed incorrectly. Wouldn't show as a vacuum leak, but it'll put a helluva lot of vacuum in the crankcase and find the easiest seal to pull air past. That'll make some weird noises.
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The PCV valve doesn't have a hose on it and I can feel vacuum. So, I think that's a no go.

Croatan_Kid said:
If it doesn't...it's something else!

You could pull the rear main seal cover and put your eyes on the rear-most cam bearing, if it comes to that. I could see where, possibly, one of those could rotate, cut off oil flow to a cam journal, and make some noise.
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Yeah, I'm close to pulling the engine. I really don't want to do that.
 
That noise is so low-frequency that it sounds like an accessory, or at least as slow as the cam drive (1/2 crank speed). Does not sound like crank shaft RPM based on your video. I am assuming you ruled out accessories based on noise location so you probably did not pull the serpentine belt.
 
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OnlyOneDR said:
That noise is so low-frequency that it sounds like an accessory, or at least as slow as the cam drive (1/2 crank speed). Does not sound like crank shaft RPM based on your video. I am assuming you ruled out accessories based on noise location so you probably did not pull the serpentine belt.
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ran with no belt. same noise
 
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