Forcefed86

iTrader: (4)

I know most of these noise threads are next to pointless. But I figured I’d try on the off chance someone ran across something similar….

Recently put together a 5.3 SBE deal. I have a high-pitched noise that is only present at say 1800+ rpm and gets louder with additional RPM. It sounds exactly like a bearing going out in the alternator or water pump, idler pulley etc. And its clearly coming from the front of the engine.

Its not an "internal engine" kinda noise in my experience. So I eliminated the accessories and idler pulleys... Then eliminated the belt all together and the noise is still present.

Has anyone ever had timing chains/components making loud high pitched “spun bearing” types of noise?

I’ve built a dozen of these things and have never had anything like this. Driving me crazy.

Just dumped the oil and split the filter as well. Nothing indicating an internal metal issue.

G Atsma

I'd be tempted to say something with the front seal, oil pump, or a cam bearing. With the belt off, what else could it be?

Full Power

Air ( Vacuum ) ?
Cracked manifold, or throttle body/IAC ?

Forcefed86

iTrader: (4)

That’s kinda where I’m at. I’ve seen a bunch of cam bearings crap out. But never heard one squeal before. Also would think id see metal in the oil… Basically trying to exhaust every possibility before just pulling it out and tearing into it. Kills me having just got it in and running is all.

Don't think its a leak as it sounds mechanical... Its almost chirpy like a bird call. But I haven't hosed it all down good with ether yet. Might give that a try.

Thks all.

GMRL

Most of the "chirp" type noises in these motors end up being lifter related in my experience. Does it go away if you remove the oil cap while its running?

Forcefed86

iTrader: (4)

Haven't heard of that. I will def give it a shot. does have low mileage used OEM lifters. Installed with new trays.

thanks

Che70velle

iTrader: (6)

Chirping is usually lifter has turned. Are you running a cam sprocket with the Torrington bearing by chance?

CattleAc

iTrader: (7)

I've had three with the chirp after belt removal, all were lifters...

Forcefed86

iTrader: (4)

No, running a BTR OEM style timing gear and new chain. Bolted directly to a new TSP camshaft. So assuming its a lifter, the only option is to pull the head and run new lifters? Or does that generally indicate one of the lifter bores is hosed. What generally causes a lifter to rotate? I also installed new lifter trays when I did the cam.

Che70velle

iTrader: (6)

Yeah, ASSuming it’s a lifter, you’ll have to pull the heads, etc. The issue at hand is the metal that’s been removed from the lifter wheel and the cam lobe. It’s hardened steel and it’s gone somewhere in there. I’ve seen it often take out the adjacent cylinder because the cam lobes are right there at the piston skirts. So, as the cam is turning, it’s throwing metal shavings and it often hits the piston skirts that are at BDC. As the skirt zings back up the cylinder it drags metal shavings with it… not good.
Your first step should be to cut the oil filter open and see what it looks like. If it’s clean, you may have dodged a bullet and might not have any issues with debris in there because it hasn’t run enough to hurt anything. Bottom line is you’ll have to do some exploring to see what’s gone wrong…the ASSumption that it’s a lifter is merely a guess. Hope I’m wrong, but a chirping is typically a lifter.