Oil pressure drops to 0 at low rpms what's up?

[gfarr]

I recently purchased my first corvette, 1988. The oil pressure was around 30-50 when I purchased it and dropped after driving it for a few hours. It has steadilly gone down and yesterday, the low pressure light went on at a stop and was only 20-30 at higher rpms. I changed the oil and filter and this had no effect. It had Mobil 1 in it and it didn't look bad. Thanks for your ideas!

 

[SPANISHVETTS]

Nothing good can come from low oil pressure.:ugh

I would check the sender first or replace it since it is the cheapest part that could go bad.

After that hope for a bad oil pump, otherwise you are probably in for a rebuild. The normal cause for loss of oil pressure is excessive wear of the Crank Shaft bearings. The quicker you find the problem the less expensive it will be to repair.

Whatever you do do not run the engine without oil pressure. If you do you will destroy the lower end in a matter of seconds.

 

[gfarr]

Thanks! I hope it's the sender.

 

[Vettefan87]

When it was running did you hear any knocking? If so the damage is done and you will need probably a full lower end rebuild. I hope it has not come to that, but it is weird went that you had oil pressure, and it steadily went down to zero. Definetly don't run the motor. Get a manual gauge like said and check it that way, if you have oil pressure at idle, you are probably safe. Keep us informed.

 

[DRTH VTR]

just curious- Did you buy it from a reputable dealer?

There are oill products that can hide smoking and other issues for a short time.

 

[oldace84]

just curious- Did you buy it from a reputable dealer?

There are oill products that can hide smoking and other issues for a short time.

I agree!

 

[gfarr]

I purchased it private party. There is no abnormal sound when it's running. And the oil pressure is higher when the engine is cold and when it's hot, and above 1000 rpms, it still has 20-30 lbs pressure. Power has not changed either. It's parked until I'm able to figure this out. I'll keep you up to date after the manual test. Thanks

 

[I_R_DA_ONE]

I had this happen on my 69 L88 engine and what it was ,,,the pick up on the oil pump had come loose...... Do not drive it like this or get a lot of money set aside..... You did not tell us how many miles were on the car and what type of engine is it??????

 

[gfarr]

159K with L98.

 

[I_R_DA_ONE]

I don't want to alarm you but you may have a loose main bearing and all is well until the oil heats up....the oil gets thinner and you loose pressure.....try all the other sugestions that have been mentioned,, and if that does't work ....then go to a standard oil....maybe Havolin 20-50 or higher and see if the oil pressure stays high after it warms up....
Mike