oil pressure drops!!!

load71

New Member
Oct 28, 2004
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My friend has a 1991 GT Convert with only 36000 miles on the bottom end, and he put on the holley system Max kit, along with 75 mm mass 24 lb injectors and so on. While driving the oil pressure is about 25 to 30 lbs, but when he stops it goes to 0. The check engine lights comes on and goes off every now and then. The pressure jumps up as soon as you touch the gas. What could it be? I hope its not a spun bearing or anything. Thanks
 
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you know what? 25-30 lbs while driving is too low! I bet a new oil pump is in order!!

The symptoms sounds like worn parts and better deal with it before internal damage is realized...

Search on a way to test the pump or just replace it.

gary
 
I think it's worn parts

Like camshaft oil pressure drive gear wear, oil pump mechanics wear, etc

It is an intermittant problem (going to zero) but a constant problem too (25-30 lbs at cruise)

i WOULD REPLACE THE PUMP TODAY! aND SEE HOW IT DRIVES.

(sorry about the caps, just looked up from the keyboard)

Once the pump is installed (i think you can do it with the engine in the car, not sure)

Not much else it could be. If it's not the pump it's the gear that drives it!

Compression test good?

Car drive normally?

How long has this been going on?
 
I've noticed that to for my car. I notice it when the car is running for a while. I have also wondered what the cause might be. Anyone change their oil pump? Is it hard/easy?
 
Was the bottom end rebuilt?

These symptoms sound like a missing gasket on the pickup tube or where the pump mounts to the block.

If it is a rebuild, it may be worth while to chat with the builder on the issue of these gaskets.

Good luck
 
Interesting...

Did you drive a car where the oil pump was installed without the gasket and the car exhibited those symptoms??

What do you expect the builder to say?? "Oh, I never use gaskets!", or he might say: "Gee, I thought I had a few extra parts!"

Just change the pump )(or have it changed) and new gaskets will be included.

Delay will be a bad thing. I am trying to stress that the "great" way the car drives will not continue long with 0-35 oil pressure.
 
NO it is the orginal 36000 miles not rebuild. So there is no builder to talk to. It had synthetic(spelling?) 10-30, and we just put in regular 10-40 and it gain about 6 lbs of pressure.
 
The only question I didn't see was, How's the level? Does it read full? I realize this is basic and obvious....but, did he check the oil level? What about the front and rear of the intake...did he use the pos rubber seals (that rarely seal) or did he go the silicon bead?

Jim

:bang: I see where you guys put in fresh oil....doh!!! Check it again, see if it's losing it somewhere...
 
He used silicon bead for the lower intake. I think i just going to try to take off the oil pan, and replace the pump. Any advice or sugguestions. Is there a link or write of how to do this. Any help would be awesome. Thanks guys
 
I've done many pumps in the car.. just gotta jack the motor up till the bellhousing hits the fire wall.. it gives you JUST enough clearance to get the pump in and out. You can't get the oil pan out with it in the car because of the double sump design. Sounds to me like it COULD be either... an oil pump, or major bearing clearances... But I would suspect oil pump failure before bearing failure due to the mileage... but you never know. Have fun and good luck either way!!!

Nick
 
garystocker said:
you know what? 25-30 lbs while driving is too low! I bet a new oil pump is in order!!

The symptoms sounds like worn parts and better deal with it before internal damage is realized...

Search on a way to test the pump or just replace it.

gary

:stupid: thats what im thinking, cause i run like 60 getting somewhere, and like 30 at idle.
 
yeah i know. My car when it had 170,000 miles was getting 30lbs on a hot idle, and around 45-50 driving. It was great. Now this only has 36,000 miles it can barley get 30!
 
i replaced an oil pump on monday with the engine in the car. it's a pretty tight squeeze, but with two people it's possible. took a few hours, but we got it back together. hardest part was getting the steering rack back on because we took it off for clearance. oh ya, dont drop the gaskets in the oil pan either.
 
Ok, today i called Alfredo from Valley Performance, he deals with a lot of mustangs, and i explain to him my problem. He believes that it is not the pump because he said that they do not usually get weak they just brake. So that would mean that i wouldnt have any oil pressure. He strongly believes that it maybe the bearings, not the pump. Could it just be possible that the screen is clog and thats why i am getting some pressure. The car only has 36000 miles on it, i just cant believe that the bearing are shot. Sorry for so many questions.