oil pressure problem

[fastmatt]

i have a 98 z28 with 106,000 miles on it and my problem is i have good oil pressure when i star the engine and as the engine heats up the oil pressure drops off and it goes from 60 cold to 20 hot and when i rev the motor the pressure will spike and quickly drops. and when the engine is hot and low pressure you can hear the valveterain. i heard the early motors had bad oil pumps? anybody had similar problems?

[94TAGT]

Your oil pressure is fine. Many have seen 10psi at idle.

[rooster99ss]

Originally Posted by 94TAGT

Your oil pressure is fine. Many have seen 10psi at idle.

bullshit. maybe on a 94 LT1 because the 94 GM motors had oil pressure problems, but not on an LS1. Lowest oil pressure you should see is maybe 30 at an idle, and that's actually low for an LS1.

At first I was going to say maybe it was a sending unit problem, because those actually seem to break all the time, but if you can hear the valvetrain and all of that, then obviously it is a pressure problem.

Have you tried changing the oil? there could be a restriction in the filter causing it. It sure seems like it could be some kind of restriction to me because of the way that it spikes when you rev the motor.

Other than that, oil pumps are cheap man. You can get a good Melling H/V oil pump from WS6Store for $139

http://www.ws6project.com/user_stor/...ath=235_87_472

[youngrigo aka NVEEOUS]

Yes - you may want to look into a new oil pump. Mine idles around 40 - 50 psi and damn near goes all the way up when full throttle.... Oil pressure is the main reason alot of motors goes boom!

[94TAGT]

Originally Posted by rooster99ss

bullshit. maybe on a 94 LT1 because the 94 GM motors had oil pressure problems, but not on an LS1. Lowest oil pressure you should see is maybe 30 at an idle, and that's actually low for an LS1.

At first I was going to say maybe it was a sending unit problem, because those actually seem to break all the time, but if you can hear the valvetrain and all of that, then obviously it is a pressure problem.

Have you tried changing the oil? there could be a restriction in the filter causing it. It sure seems like it could be some kind of restriction to me because of the way that it spikes when you rev the motor.

Other than that, oil pumps are cheap man. You can get a good Melling H/V oil pump from WS6Store for $139

http://www.ws6project.com/user_stor/...ath=235_87_472

I thought it read 93 not 98. My bad. As for oil pressure, I didn't say mine was idleing at 10, I said many have seen. It's all over the forums. From what I understand, it was 93's and EARLY 94's that had the oil pressure problems. Late 94's were fixed, pressure isn't as good as the LS-1's but better. I do know if you get even the GM Perfomance oil pump it will raise up the pressure as well for the LT-1's. The corvette LT-1 forums seem to have a better wealth of knowledge for the LT-1 than what I have seen from the F-Body forums running around.

[fastmatt]

i changed the oil last fall befor i parked it for the winter. i notised the pressur problem the second time i got to drive it this spring. im thinking of just replacin the pump, and crossing my fingers that its not the mains.

[BenSS]

This is true about the 94's oil pressure, i can see mine going boom soon!

[ZEEMAN]

The rule of thumb is 10psi for every 1000 rpms.

[9T8W66]

Originally Posted by ZEEMAN

The rule of thumb is 10psi for every 1000 rpms.

Tru Dat

Minumum oil pressure for an LS1 Hot.
6psi @ 1000 rpm
18psi @ 2000 rpm
24psi @ 4000 rpm

If mine was this low I'd replace the pump myself but 20-25 psi @ idle (Mine has been this way for years) is safe.

[fastmatt]

well ive started the tear-down took out the old oil pump and it looks fine. dropped a main cap and the bearing looks new. so im a little confused but im going ahead and putting in a meling h/v pump and a double roller timing set while im in there, and a slp under-drive pulley and a 160 deg thermostat.

[redhotlt1]

replace save the motor if it`s not the issue at least you`ll know its got a good pump in it. you`ll sleep better and be more at ease when you drive it.

[fastmatt]

well i put the new oil pump in and it ran great for 40min i let the car warm up in the garage and the oil pressur was great car sounded good, the next day fired up the car and the oil pressur was half of what it was the night befor, thought i had a bad sender drove the car down to the corner to get some gas and on the way back lost all oil presur, but there was no noise coming from the motor so i assumed it was a bad sender then went back out for a drive and started to hear lots of ticking, towed the car back, and im at a loss for ideas. im geting ready to drop the motor out of the car and tear it down, and check everything out.