BUILD THREAD Project Olds Cool (Recognition!!)

[motorheadmike]

Sounds like somebody still has a sore *ss! Or did you just get up on the wrong side of the world today?
I don’t know who you’re referring to with a “sub-200hp boat anchor”, but it ain’t this hombré. Neither of my rides fall into that classification.
😏

I am talking more about the plight of the average G-Body with a Gen I SBC. The dialogue indicated there are gaps forming in suitable replacement parts to keep them running well. Or people just like to complain.

If it is the prior, for example, a basic LS swap with a carb (barf!) would negate that issue.

Beats chasing down a quality distributor cap and whining the whole time. The same could be applied to brakes, suspensions, transmissions, or anything else that can be updated. Resto-modding makes good sense.

If I really wanted to go off on a subject you would know it.

 

[Rktpwrd]

Hey, wassup guys.
I’ve been pretty quiet here lately, partly because I’ve been working the last 2 weeks straight without a break, and partly because I’m licking my wounds a bit.

You see, Olds Cool is sick. What I thought was the growling alternator bearings definitely was, but it also wasn’t the source of the noise that we were hearing. After reinstalling the repaired alternator, I fired the car up and the noise was still there.

In the interest of eliminating any variables, I removed the alternator and power steering belts thereby isolating the FEAD components, noise is still there. Tonight I put the car back up on stands and ran it for a bit while listening underneath with a mechanics stethoscope.

It’s still inconclusive as to what’s causing the sound, but I’ve been able to narrow down the general location of it significantly. It’s at the lower front of the engine, right at or near the harmonic balancer. Not high enough to be anything camshaft related, not far back enough to be anything main bearing or oil pump related. Oil pressure is mint, rock solid and never wavers. So I highly doubt it’s any kind of engine bearing or oil pump related.

No, like I said it seems to be right at the balancer. Balancer itself looks fine, no evidence of the elastomer failing or the halves spinning, and I never installed a cheater sleeve on the crank snout. My Red Seal Journeyman mechanic friend and boss is gonna come by on Saturday to have a look and listen to it himself, at this point we’re kind of thinking it might be the timing cover shaft seal spinning in the cover, or possibly something in the crank sprocket/timing chain assembly.

We’ve also ruled out the mechanical fuel pump, the noise isn’t emanating from there. It’s a real head scratcher, I’m open to any and all possibilities that it could be based on y’all’s experiences. It can best be described as sounding like a bad roller bearing or belt squealing, and it’s intermittent. Comes and goes, varying the engine rpm has little to no effect on when it happens.

In other news, I’ve been quietly gathering parts for the upcoming diff overhaul, Amazon has been my friend lately. New axle bearing and seal kits, new bearings pressed on the carrier, a new cover gasket, fresh dino gear oil, and a few other odds and ends. A new stock Dorman cover for the 8.5” showed up today too:

As for the carrier, I’ve got the clutches in it soaking in the gear oil as we speak:

This is a rebuilt carrier with new clutches, all it needs is the ring gear from my open carrier swapped onto it, and dropped back in. Of course we’ll be checking the pattern once we’re done, I have a good selection of new shims on hand for that, and new C clips too just for good measure.

But for now, we sit and wait till Saturday. If I have to tear down the entire front of the engine to find the source of the noise, that’s gonna take precedence over the rearend overhaul.

I hate the wait, to me it’s worse than actually knowing what the problem is.

D.

 

[scoti]

This is hopefully not going to spiral on you. Sucks when these 'WTF' issues arise & a definitive source can't be easily pin-pointed.

 

[Streetbu]

So the noise doesn't change with engine rpm?

 

[Tony1968]

I know audio is hard to capture perfectly but maybe take a video of her running so we can speculate a little.

 

[69hurstolds]

You're missing your posi lube additive. Didn't whoever rebuild that differential already soak those clutches? They should have. Posi lube additive is GM p/n 88900330 or equivalent.

Also, beware of those Timken boxes. They have a tendency to sell you just races or just roller bearings, along with sets. It appears what you have on the bench is the part number just for the races (LM501314). Did you already put the new roller bearings on the differential? If needed, the matching roller bearing itself is LM501349. You could get the entire set by ordering Timken SET69. That has both part numbers inside the box. Or get GM p/n 9420095. They come as a Timken set, too. Wait, never mind, I see you already got the new bearings on the carrier.

Streetbu , I think he means that varying rpm has no effect on when the noise shows up or goes away if I read it right. If it's inside the engine it HAS to vary the tempo with rpm. If it doesn't, it's not a moving part.

Taking off the belts and it's still doing it rules out the water pump. That would have been my next guess.

Is the oil clean and not metalflakey? Bad engine bearings usually don't quiet down, they just get worse. But there's always those mystery things.

How long has it been since rebuild? Or timing chain replacement? Using a cam button? If the chain is old, could it be stretched to the point of scraping/hitting the cover on the slack side when running? I know, that's a "stretch". 🙂

If you suspect it's timing chain stuff, I'd set up some time and replace the timing chain with a quality double roller or even a single roller. It gets you inside the cover to check everything anyway and when you're done you got new parts installed. We like spending your money for you, you know.

But if all that's been recent since a timing chain change, then I would highly suspect the balancer. If it's stock, is it moving or wobbling at all? How's the crank pulley? Still solid and not wobbly? Normally balancers are a ticking/knock sound. But I had a scrape/high pitch squeal depending on rpm on a 455 Olds many moons ago. The balancer ring walked backwards a bit and was scraping junk. Took me a bit to figure that out, but then again, that was the days where you could buy a new GM balancer for $40-$50.

Sorry, just shooting in the dark. You're there and it's hard to trace, here on the webz, it's much harder.

 

[old80cs]

Good luck with the repair, hope it’s not anything too serious and costly. 👍

 

[motorheadmike]

That sound? It's the car telling you it's time for an LS-swap.

 

[69hurstolds]

That sound? It's the car telling you it's time for an LS-swap.

Don't do it! Reseach has concluded "LS" is 40% on its way to be "LoSer". Mathematically, there's no way around it. 🙂

Well, wait. LS has been so overplayed it sort of is considered "old school" today. But you have to wait a couple of months. LS swaps are only allowed in the month of "Meh."

 

[81cutlass]

Have you got the engine up to temp lately? How many miles has it seen? Spinning the seal is possible but unlikely. If it was it should be leaking.

It's a late 80's center bolt valve cover SBC correct? Roller/Flat tappet?