This high pitched squealing noise coming from the bottom of my new TPI engine is driving me bananas! It doesn't start until the engine gets to full op temp, and only does it at idle.
With a hose crammed to my ear, it seems to be coming from the rear near the flywheel, but the flywheel isn't touching anything and I have removed the flywheel cover. I've sprayed oil all over the flywheel and the rear of the crank shaft where the flywheel bolts to it, but no help. The oil pressure seems to be a little low too, like 25psi at idle.
I wouldn't think that an internal noise could be this loud outside the engine, but could it? Like the oil pump shaft scrapping on something?
Any other ideas?



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Rob
High Performance & Party page
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89 TTA #426 20th Anniversary turbo 3.8 bone stock
79 TA 6.6l - all original stock
94 Silverado Tuned Port Injected
87 Grand National- lil' ole V6, 12.40 @ 108 w/1.79 60'
95 Trans Am Conv.- LT1

 

That oil pressure is good.. is this a 5-speed car?

 

No its a 4-speed automatic. All my other cars hold just under 40psi oil pressure at idle, would have thought with a new tight engine it would have been higher is why I was wondering. The squeal goes away when I get above about 1000 rpms, not sure if its because the rpms being higher or the oil pressure getting higher. Noise is definitely not from the front of the engine.

 

Could a spun rod bearing squeal like a fan belt noise?? It sounds like it is only at a certain position of the crank shaft, its not a continuous squeal, but like a squealling wheel bearing....squeek...squeek....squeek....

 

I'd hate to think of (or list) what it could be... that could be a real scary list or it could be something silly like the flywheel hitting the starter gear teeth. It could be inside the engine, but thats hard to determine from here without hearing the noise its making in person.

I think that maybe you should drain the oil and see if theres an unusual amount of metal fragments in it.

 

I HAVE THE SAME THING ON MY NEWLY ASSEMBLED ENGINE. NOISE STARTED AFTER ABOUT 500 MILES. SOUNDED LIKE A BELT SLIPPING, OR A BAD WATER PUMP. REPLACED THE WATER PUMP, CHANGED THE BELTS (A/C AND PS WERE GLAZED ON EDGES). THEN I ALLIGNED THE PULLIES (DO NOT HAVE A SERPENTINE). MINE DOES NOT DO IT ALL THE TIME, BUT LIKE YOURS, THE ENGINE HAS TO BE HOT WITH THE ENGINE AT IDLE. TAKING IT OUT OF GEAR WILL MAKE IT GO ALMOST TOTALLY AWAY. MINE SOUNDS LIKE IT IS FROM THE FRONT, BUT WHEN YOU ARE ON THE GROUND, IT SOMETIMES SOUNDS LIKE IT IS FURTHER BACK. I WILL CONTINEU TO DIG AND TO WATCH THE REPLIES TO YOUR POST.

 

Blueta, mine started at about 300 miles on mine.
Today after I got to work, it wasn't near as loud as it usually is.
Again, it only does it after is been driven a while and hot.
When I got home this afternoon, it was almost not noticable now, it now has about 400 miles on it.
If a rod bearing spun out, I'd think I would have some rod knock, but there's not any I can hear, yet the scan tool picks up some Spark Retard from the knock sensor every once in a while but no real pattern to it.
I guess if one of the main bearings spun, then there may be no knock associated to it.
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I'll be draining the oil this weekend to see what I find and straining the oil from the container and see what I find in the strainer.

 

Well, I drained the oil and strained it thru a paper towel and found only a few particals of metal about the size of a grain of sand, but a moderate amount of "powdered" shiney metal in the bottom of the pan.
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Wouldn't I see something more considering this is a brand new engine and only the second oil change if it spun a bearing? The squealing didn't start until some tim after the first oil change.

 

Dropped pan and removed all rod end caps, found nothing!
All the bearing were in perfect shape, also checked the rear main bearing, it was fine too!!
I'm going to put it back together and keep on driving unless anyone has any other ideas??

 

AIR pump or idler pulley. Both of mine are making squealing noises, only after it gets warm.

 

Clutch wearing in or dragging? Maybe torsional damper rubbing an oil cooler line? I can't think of much else that hasn't already been discussed. Sorry man.

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1990 IROC 350
Mods: Too busy trying to make it run right to mod it.
Airfoil, Dynomax cat-back, MSD coil, 180 t-stat, Bald Eagle tires,
Hypertech fan switch, Accel 23# injectors, Holley module, ported plenum,
Ported Daytona Yellow stock base, Moroso valve covers, other stuff,
Streetdampr, Ruger P95DC, hot wife, new oil filter, !cats, !TBC, !AIR.
18.0 @ 85MPH since I'm one big-a$$ MF
"It's better to have and not need than to need and not have."

 

Nope,none of those things. Believe me, I looked at everything before taking the pan off. Had the old "hose to the ear" trick, and the noise was definitely coming from the rear passenger side corner of the bottom of the engine.
The crank shaft counter weights at the back were very very close to scrapping the block in several places or the main bearing caps and did have some very fine scratches.
I'm going to assume that maybe it is rubbing once it gets to full op temp and the metal expands some.
The noise was going away the more I drove, s I'll just keep changing the oil very often until the noise quits and the "powdered" metal quits showing up in the oil.
Thanks guys

 

maybe the distributor gear on the cam? maybe? possibly? i dont know that it would make a squealing noise but you already checked the bottome end. what ya think?

 

Could it be, that at idle your engine has a rougher movement to it?

What I am getting at, when the engine is cold it is idling high and when an engine idles higher or rev's high it runs smoother. So when it is hot and at 600rpm it will shake a bit more, right?

Perhaps your tranny mount bushing or your motor mounts are causing this problem. Or maybe the tranny lines or exhaust are rubbing on something.

Just a thought.

Mark.

 

Well, I'm not 100% certain as to what it was, but it hasn't done it again after I dropped the pan and all the rod and main bearing caps.
It was something that was rotating, its hard to describe, but when the motor would be cut off the squel would sound differently as the crank spinning would come to a stop. Kind of like a squeky wheel thats rotating and then slowly bring it to a stop.