can't get oil pressure


New Member
Jun 24, 2003
just replaced oil pump and followed instructions on how to prime it. pumped oil up to rocker arms but won't hold pressure to keep it there. have used 7 quarts while doing this and can not get the oil pump primed.

Can somebody please help me?

By the way this is in an 87 GN not 84
Wonder if you did the same thing as the dude in Hawaii, used the wrong gaskets. Gotta make sure they have all the holes.
I'm the guy in Hawaii. Check out my thread "rebuild, now no oil pressure". Did you put on a new timing cover (the high volume type?? Check the gasket between the timing cover and the thrust plate. I found that 4 out of 6 that I had in the garage wouldn't work correctly. It's hard to explain, but there is a portion near the suction of the pump that most of my gaskets have a cutout (for no apparent reason but to save money on material) which doesn't allow the thrust plate to seal correctly. I found it when I took the thrust plate off and look closely at the gasket. There was a small portion I could tell wasn't actually sealing as the timing cover didn't have any mating surface there. But your symptoms sound VERY similar to mine. I could get initial oil pressure and then it would drop off and go away. Then I would re-prime it and same thing. It was because the oil pump was sucking air in through this gasket area. I hope this helps...

If you want, I can probably take a pic of the two types of gaskets and send it too you. That may make it easier to see.

Did you install a high volume oil pump or does it already have one installed?? That's the problem I had. The mating surface of the high volume pump (in the timing cover) didn't cover the entire gasket (gasket between the timing cover and the oil pump thrust plate). I'll download the pic and send it to your e-mail. But your symptoms sound exactly the same as mine...

I've got to look again but I think the gasket I got dint look neather one of the to you sent pictures of. What thrust plate are you talking about Because I dont remeber any plate inside my oil pump.any pics would be help ful to me on this area of the thrust plate.
It's the bottom cover of the oil pump. Basically the oil pump gears go up into the timing cover, then you bolt the "thrust plate" (which I learned is actually called a 'magnetic pickup adapter' by GM) to the timing cover. This is the piece that the oil cooler adapter goes to and the oil filter. It must have been removed to get to the oil pump gears.

I'm sorry for this but does anyone have the part # for the oil pump gasket because the ones I have got is not the one that I need someone sent me pics of the one that I need.
So went to the dealer ship and they gave me the same one as the parts store did and its not right or do you have to cut it to make it fit because it does even have the holes to line it up
Well good news I think cut hole in gasket for the oil pump thrust plate and found out that it had a H V oil pump in it so the stock replacement I bought didnt do a dang thing but made funny sounds. Put old gears back in it along with a 60psi spring and now have 85psi oil cold and 20 at idle hot. But now I have a code flashing thats a 42 what did I do wrong .
It goes to the shop today12/31 to get all new bearing put in it
and now what ever the heck is causing the code 42 It ran fine but say it could be the ecm and alot of other thing that I din't touch. I figured sence you all help so much with my oil problum you could help he with this one

Thank you to the guy in hawii Happy New year to all
Took it to the shop today going to be there for at least a month
just told thenm to make it run like.Found problum for code 42 it
was the crank sensor. Moved it it dint have a code but dint run right real bad miss in it .