SPUN BEARING? NEED INFO

715Hunter

715Hunter

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Jul 28, 2022
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I'm sitting by the side of the road, my 04 LB7 just started making strange squealing noises that vary with RPM. Removed the serpentine belt and it's unchanged. Oil pressure is sitting about 15 PSI at idle, had been 30-35 at highway RPMs. No knock, oil level is normal and unchanged from 200 miles back. No vibrations. I can't think of anything that can make that noise except main or rod bearings.
Anyone ever experienced this?
 
715Hunter

715Hunter

Member
Jul 28, 2022
73
12
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Missouri
Crawled underneath while someone started it. It's extremely loud under there, and sound like it's coming from back further. Anything in an Allison that could do this?
Edit: I don't think it's possible for the CP3 or water pump to make this much noise and be in one piece. I do not know about the oil pump though.
 
715Hunter

715Hunter

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Jul 28, 2022
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Missouri
No idea. I've noticed for the last few hours that on 5-4 shifts the converter unlocks, then re-locks after 5-10 seconds. Seems odd. I don't know how converters lay out inside, or if it's even possible to make them squeal like that.
I just don't want to drive it further and completely destroy my engine or trans.
I just swapped the engine in about 3 weeks ago.
 
2004LB7

2004LB7

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I couldn't hear any squeal in the video. Only what sounded like marbles in a coffee can or something similar
 
715Hunter

715Hunter

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Jul 28, 2022
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Missouri
Well, it's definitely not something in the rotating assembly. I decided to go for broke and get a mile down the highway to a better spot. About 1/4 in the rattle turned into a grind and then stopped, and smoke started dumping from oil on the exhaust. Right now my top suspect is the turbo, as I can see oil on the exterior of the exhaust housing under the heat shield. Going to pull the intake in a bit and see if she'll spin.
 
715Hunter

715Hunter

Member
Jul 28, 2022
73
12
8
Missouri
715Hunter said:
Well, it's definitely not something in the rotating assembly. I decided to go for broke and get a mile down the highway to a better spot. About 1/4 in the rattle turned into a grind and then stopped, and smoke started dumping from oil on the exhaust. Right now my top suspect is the turbo, as I can see oil on the exterior of the exhaust housing under the heat shield. Going to pull the intake in a bit and see if she'll spin.
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The weirdest part of all this is that for several weeks, it has had a little rattle/squeak at low RPMs, that goes away with throttle. Also changes when braking. I think it must be a totally. different issue.
 
715Hunter

715Hunter

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Jul 28, 2022
73
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Missouri
Could be. Seeing as it stopped making noise right as it started dumping smoke, that seems a bit doubtful.

Anyone know where to get a turbo in Hannibal, MO? Everywhere I've called can't have one till tomorrow.
 
2004LB7

2004LB7

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1FastBrick said:
Maybe it spun a cam bearing killing the turbo.
Click to expand...
Wouldn't that starve the turbo of oil? Sounds like he has oil dripping from the exhaust.

Unless you are suggesting that the bearing moved back and is resupplying oil after the turbo damage?
 
715Hunter

715Hunter

Member
Jul 28, 2022
73
12
8
Missouri
2004LB7 said:
Wouldn't that starve the turbo of oil? Sounds like he has oil dripping from the exhaust.

Unless you are suggesting that the bearing moved back and is resupplying oil after the turbo damage?
Click to expand...
Everything I can find says that any bearing spun will drop the oil pressure.
 
1FastBrick

1FastBrick

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Dec 1, 2016
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2004LB7 said:
Wouldn't that starve the turbo of oil? Sounds like he has oil dripping from the exhaust.

Unless you are suggesting that the bearing moved back and is resupplying oil after the turbo damage?
Click to expand...
My thought was that it spun just enough to block it and not supply enough lube smoking the turbo. Once its smoked, virtualy any presure would leak pasted the smoked seal.

Was just a theory.
 
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