On 97 LT1-

Motor is back in the car (new 355), cranked it over, and no oil pressure. We let it run for 10-15 sec and got nothing on the stock guage. No oil coming up to the top of the motor either. When we kill the engine the stock pressure guage reads ~ 15 psi (after we shut it off wtf?) We started it again and no pressure 2nd time either and we immidiately shut it off.

Its running a melling high pressure pump if that makes any diff.

How long should we have to wait for oil pressure?? HELP!

 

sounds like your oil pickup fell off or your oil pump gear is stripped...

 

Or that plug in the rear of the block was removed when the block was machined. Or there is not enough oil in it.

Don't ask me how I know about these two causes of low oil pressure

Rich Krause

 

Can you please elaborate on this? What is it called? Someone else mentioned something like this to me. Its not my car, but I'm trying to help out a freind. Someone mentioned a "ball" that goes somewhere in the block and does something but I'm not really sure about all that stuff.

All I can tell you is that the block got all new freeze plugs and had oil restrictors installed. Not running that adapter piece (that has the cooling lines attatched to it) for the oil filter either, just a canton bypass.

Going to go talk to the machine shop later in the week but what should we ask about? Is there a plug in the block that would restrict oil to the top of the motor? Whats it called?

 

ttt

 

When I first got done installing a new oil pan on my parents van I had no oil pressure... let it run for a few moments and killed it..double checked everything... Fired it up again...still nothing.. Then I gave it a quick rev (about 4500rpm) and as it was comming down in RPMs it must have primed itself...

Just a stupid Idea...

If you have tried everything else its possible as otheres suggested..the pickup tube or the pump gear. Good luck.

 

We let it run a good 15-20 sec. Nothing registered on the guage and nothing coming up to the valvetrain. I'm thinking the machine shop forgot something in the block. I dont know much about the plugs and gallies in an LT1 so I have no idea what to look for.

We didnt weld or braze the pickup tube in, just press fit, and it was a tight fit so I know that didnt fall off in the first second. The gear on the pump drive wouldnt break in the first second of running, so what else is left? All that is left is something like a plug that wasnt installed right?

 

I let my parents motor run for ~30seconds the first time (long enough to visually see no pressure on gauge, walk out and check the engine, and go turn it off again), then it sat for a few minutes, and I started it again for ~ 30seconds, then revved it up a few quick times.. pressure came up really quick. Of course with a new motor I wouldnt want to risk damagine it either.

 

just pull the pan. thats the only way to tell. My guess is the pickup is to close to the floor.

 

I 2nd that...did you check clearance on it before you put it back together?

 

the pickup tube is 3/8" from the bottom of the pan.


Also I checked into that plug that goes into the engine block, #33701638, it is not a valid gm part number, and this comes from customer service at gmpartsdirect.com

 

I know your pain.

 

Crank it over with valve covers off, and spark plugs OUT/coil disconnected until you can visibly see oil coming out of the top of the pushrods.