Hey all,

Here is the problem. It is a 94Z A4 car, and the oil pressure drops down to the idling pressure line on the guage, when the car hits around 4k rpms.

When it first cranks, it is fine, it has great pressure. It is only when getting to about 4k that it drops, a significant drop.

I went through my Hanyes troubleshooting guide, and it had 7 things listed for low oil pressure. And only 2 out of the 7 apply.

Oil pump regulator valve not operating properly.

Oil pump worn or damaged.

(The other stuff was like, wrong grade of oil, clogged filter, engine overheating, ect. which none of those are possible.)

This car has around 102k on it. We just replaced the water pump.
I am wondering if it is the oil pump itself?

But I thought that when they went, THEY WENT, no gradual oil pressure lost. I thought that it was an all at once thing. Like, the oil pump goes=0 pressure.

Can some of you out there enlighten me on some ideas???


Thanks

 

I know that happened to my car when I spun a main bearing....get it checked out asap. Now I gotta do a rebuild.
-Ryan

 

I think just about every LT1 does this. Mine's done it since I bought it with 56k miles and it now has 71k miles. I personally, don't think the guage it too accurate. If you just floor it, you'll see the oil pressure rise, then fall. If you gradually bring it to redline, you'll hardly see the pressure drop.

 

http://web.camaross.com/forums/showt...ght=cavitation

I have the same problem. I also know of quite a few people that have this issue. I guess GM was aware of this, but stated that in order for the bearings to spin, the car has to have around ~26psi or lower @ 6k rpms, so they never set up a recall.

 

Thanks for the replies. Knock on wood, but I have a 95Z, that has 88k on it, that keeps 60+psi at startup, and stays in the
45-50psi range while driving, and the needle is steady. It idles around 22psi.

Take it for what it is worth, but when I changed over to regular Havoline 10-30, my pressure increased very noticebly.

NO more expensive Mobil 1, or AmsOil, or any synthetic for me!

 

Most every pre 95 lt1 has this problem. It has something to do with the entire pan/windage tray design. A member of the board fixed his with a new pan and tray.

My car has done this as long as i can remember. I just dont worry too much on it. When it goes, it goes. Nothin you can do about it. (actually there is, but i dont feel like jacking up the motor and spending money that i REALLy dont have too.

 

Sludge down in the pan that might be partially clogging the pickup screen under higher rpms can cause this too. But a friend's 79Z28 with a fresh 355 does this a little too on a high volumne pump and stock pressure relief spring. My old S10 4.3 used to do this too, but my Jeep doesn't and it has 143k. Must be an oil pan baffle thing...

Jason

 

same thing here... I was told that it is the oil sloshing back in the pan so it is harder to get to teh pump or something like that