Dr. Dynamics

I was having aprox 1.5 bar to 1 bar oil pressure when I took a small ride around town and stopping at idle. Every time I turned the car off and started back up after a little, the lifters would start sounding and oil pressure will rise after about 5 seconds.

I recently changed the oil (cASTROL 20W 50). And everything appears fine. But its starting again with the lifters sounding when temp is hot (normal).
AND i noticed yesterday that on the driveway hill (about 20 degrees steep) the oil pressure really dropped and lifters started sounding a lot.

I cleaned OPRV with seafoam. Is the OPRV supposed to be soft springing?
And as the title says, what are the symptoms and do they not act with cold oil?

Dr. Dynamics

anyone?

Antonio

I went through a somewhat similar saga last year. Some good information there.

Assuming that you trully have low oil pressure and not a false reading, I have few more suggestions. Pull the DME relay so the engine doesn't start. Take out the OPRV. Have someone crank the engine. If lots of oil oozes out of the OPRV hole as soon as the engine turns, then your pickup tube and the engine internals are probably okay. In that case I would replace the oil filter and/or the OPRV and see what happens.

If it takes a while for oil to come out or the flow is weak, my money is on a cracked pickup tube. It could also be the oil pump or rod bearings but lets not go ther yet.

Charlie

I had a situation where my OPRV was stuck open and my pump could not pull any oil. As soom as I corrected the problem the pump worked. This would indicate to me if you remove the OPRV your pump will not pull oil from the pan. When I looked at an oil flow diagram I could see why this would be the case.

future

A fcuked engine

Antonio

Not enough to register any pressure but enough to show that the pickup tube is still intact.

Charlie

Mine would not pull the first drop. Mine was a newly built engine and with the OPRV stuck open the pump would only circulate air. It did not form a suction from the pan. Found this diagram.

Dr. Dynamics

I can see according to the diagram there is no oil cooler bypass in case of thermostat failure or cold temp?
If a thermostat fails to open you should get instant pressure anyways since its similar to a cold start condition. right?

How hards shoud be the springback on the OPRV. Mine was very smooth. Is there a way to test it? What supplier $$$$ do you recommend. I saw it on vertex for mid 400s.!!!!!!!!!!!!!!!!

Charlie

The only way I know to test the oprv would be to borrow one that is good and try in your car.
The other reasons for low oil pressure besides the oprv and cracked pick-up tube would be a bad O-ring at the pick-up tube or worn bearings. Hopefully it is the oprv as that would be the easiest fix.

RajDatta

You should also check to make sure your main crank bolt is torqued to 155lbs/ft. If it is loose, you will have similar symptoms.
Pickup tubes normally crack from a misaligned lower bs. Did you have a misaligned lower bs?
Raj

Dr. Dynamics

Charlie,
Thats a good thing to check! Though I want to avoid taking the pan off.

968
I definetely will check that since I did install a Clewett Eng Damper for my MS setup. My BSs are not misaligned but the lower one does make a whining sound that bugs the hell out of me. Causing an oil leak at the front seal also.