77c10bowtie

Swapped junkyard 6.0 into a C10, did a cam and springs and after startup I noticed only 12psi, Bottom of cam lobes wet. No oil coming up to valve covers, maybe it never had pressure.

Things I checked and double checked but didn't help:
-Pickup tube oring- was good, replaced and double checked again after install.
-Cam plate, replaced twice thinking the replacement didn't look right
-Oil pump, seemed good, replaced anyway
-Pickup tube for blockage, none
-Oil pan for blockage, none
-Original oil pan gasket had tear near filter port- replaced
-Oil filter bypass elbow for blockage, replaced gasket
-Galley plug at barbell to verify it's present, not sure if its bypassing or not but it's there, OEM plastic.

Can the barbell cause low pressure even if it's installed, I see no signs this motor has ever been apart before.

Anything else I didn't check? Cam bearings had the usual ls wear nothing extreme, no metal in pan. Out of ideas...

chrisfrost

iTrader: (8)

Hello 77c10bowtie did You put any oil in the oil pump ? Or did You have it apart ? I believe whenever disassembling the oil pump when assembling You should put some oil in the internal parts to help it pull oil from the pan. Or maybe the o-ring is the wrong 1 or got pinched or something. When installing pick up tube You want to oil o-ring or grease o-ring .

77c10bowtie

The issue was present with the original stock oil pump and the original o-ring. I only swapped them to rule out the issue. So nothing has changed. Still 12 psi before and after.

MySons68C20

How are you measuring oil pressure?

77c10bowtie

The Terminator is reading it off the port at the back of the block up top where the intake is. Yes I know it's not a mechanical gauge but if I don't have oil coming up to my heads at all then something is wrong. The cam is getting oil though I know that much.

MySons68C20

Do you have any history why the donor vehicle was parked?

77c10bowtie

Unfortunately I have no history on the donor, I got the motor already pulled, the motor itself is very clean inside though, the pan had no sediment.

MySons68C20

Does oil pressure rise when you rev the engine? I know you stated no oil to the top end......are the lifters getting pressurized or just doing the clacky clack?

77c10bowtie

Interesting point you've made, I'll have to check that. The lifters don't immediately start clacking but they do after about 30-45 seconds or so, I only got there once when I first didn't realize it didn't have pressure, I just figured something was ticking due to zero oil in the valvetrain

Che70velle

iTrader: (6)

Wouldn’t be the first cam swap Ive seen take a cam bearing out. That’s where I’d start. I’ve seen a lot of camshafts show up bent. Not bent to where you can see it with your eyes, but I’m talking .003-.006 out. It will cause a cam bearing to walk every time after startup. And often times the cam will turn just fine in the block by hand after install.
​​​​​​….edit…have you cut the oil filter open to look by chance?

JC316

iTrader: (1)

I bought a WS6 Convertible with an LQ4 swapped in. It walked a cam bearing out of it's bore and it was dangling on the camshaft. Drove it from Shreveport to Dallas with between 0-7PSI. Wouldn't shock me to see a problem with the cam bearings.

77c10bowtie

A cam bearing is what I was hoping wasn't the issue, I guess my only real option left is to pull the cam and check it out though. I don't have enough time on the motor for the filter to have anything in it I don't think but I guess I can also try that.

strutaeng

Maybe the engine was just simply worn out even before you swapped it? If it's not the cam bearings, I mean.

Maybe pop a few rod bearings? And main bearings?

1FastBrick

iTrader: (16)

I would agree with a cam bearing likely having been knocked loose.

77c10bowtie

It's definitely not worn out, there's no major wear on anything internal, the old cam looked great and even the original cam bearings looked good surprisingly.

I'm going to pull the cam back out and take a gander

grinder11

iTrader: (1)

I once had the #5 cam bearing walk forward on an LS1 block, uncover the oil feed, and pressure dropped to zero. However, this happened after only 600 miles of driving. Until then, the lifters oiled just fine.....

77c10bowtie

Alright everyone the final verdict is #3 cam bearing spun off the original cam, it was sitting in the cam valley although the stock cam has very little wear, it couldn't have been the new cam because it's still flawless. I'll put new cam bearings in and button it up. I can't believe the one thing I suspected the least ended up being the issue.

Che70velle

iTrader: (6)

Dont assume it couldn’t be the new camshaft. I’ve seen this countless times, when a new camshaft isn’t exactly true it will walk out the center bearing often. The “whipping” effect will push the bearing out of its journal. Doesn’t take much at all. Put the new cam in a fixture and measure it at the center journal with a dial indicator for runout.

77c10bowtie

I dug the old cam out of the scrap pile. the #3 journal is much darker than the other journals. I originally remember it looking fine but now I can see it's really bad. I can however measure the journals just to be sure.

Che70velle

iTrader: (6)

Gotcha. The darker journal should have been an indicator to you that there was a bearing issue. Anytime you remove any internal engine part for whatever reason, a careful examination is essential. Kinda like an autopsy. The parts removed will “speak” to you in many ways. It’s always good to check new cam for runout, regardless. I’ve seen too many that weren’t in spec. So being as how the original cam here is darkened, you might have some metal in the engine…maybe. Use a bright light and look at everything you can. An oil change is essential here. Good catch sir.