UPDATE:
OK, I replaced the OPRV with a brand new valve, replaced the thermostat as per Joshs suggestion, replaced the oil cooler seals while i was there, torqued the crank bold down again, rod bearings were replaced 10k miles ago. I STILL have low oil pressure. Light will flicker at idle, and once the oil is warmed up will not go over 3 bar. The oil pressure drops a little bit on boost (half bar). What are the other possibilities? Could the turbo be going on me? Will this cause low pressure? HELP!!
Also, I had a decent sized metal chunk (quarter of a pencil eraser) stuck in my OPRV when I took it out. uhoh. Any ideas?


Original thread:

First off, sorry I keep making these stupid Oil pressure issue threads. There are far to many on here to start with but this is a really odd problem.

So I am having oil pressure issues. Heres the symptoms:
-low oil pressure once oil warms up. no higher then 3 bar, idles at .5 bar
-sometimes when starting the car I will have 0 oil pressure

I have put three different OPRVs in and all have the same problem. BUT. the car will have 0 oil pressure, i will put a different valve in, and it will work but once the car warms up i will end up with the same problem.

Today I took the valve out, and it was stuck! I put a screw driver in it and freed it up, and the oil pressure went up upon starting the car again, but after a little while the same problems persisted.

I have the same issue with three different used valves. but changing the valve fixes the problem temporarily.

What could the issue be? Do I have three bad valves? Is there some other issue that could possibly affect the valve?? Thanks for the help guys,

 

Also, for what it is worth, I have done the following:
Checked the torque on the crank bolt, re-primed the oil pump, rod bearings have been recently replaced. Only thing left to do would be to check the oil cooler thermostat as suggested by Josh. (Im having a hard time finding the proper tools though or I would have done this)

 

I changed out my valve and it seemed at first like maybe it fixed my issues too. I am not sure you have the same issue as I did but as easy as it is (with the right tools) to check that thermostat it is worth doing. I would be driving along and see low oil pressue and if I pulled over and turned the car off for just a minute it would be fine when I restarted it....

 

Jeff, has the thermostat housing been off any time in the recent past? The only thing I can think of that might cause your simptoms is a misalignment between the block and the housing causing the OPRV to bind slightly the first time it was forced open by the oil pressure. Try freeing up your valve and then running the engine up to operating temp without revving it, see if the oil pressure is any higher like that. If you think the housing is misaligned, I have an alignment tool I could lend you if you promise to send it back to me.

Good luck, Mark T.

 

What you're describing could be worn bearings/large bearing gaps, or oil supply leakage somewhere in the system and nothing to do with the OPRV. As bearings wear the oil volume of the pump is consumed by the bearings so you can't build pressure. The situation gets worse as the oil temperature increases and the viscosity reduces. Extreme example is losing a rod bearing and then you lose all oil pressure.

How fresh is the motor?

 

Thanks for the replies guys. MHT - I have the alignment tool and checked the alignment when the valve was out today and it is aligned correctly.

samluke - Rod bearings were replaced 15k miles ago, they should be fine. The problem wouldn't be so sporadic if that was the problem right?

Josh - You have no idea how hard I tried to source the correct tools to check the stupid thermostat. I will order the tools online to check that out though asap. I will have your valve back to you asap too. Im ordering a new valve as well for the hell of it.

 

Not sure I understand which "special tools" are needed to get access to the thermostat for the oil cooler.
You just need a big allen key to release the cap beside the oil filter seat and then put the thermostat in hot water to check if it opens at the temperature that is stamped on it.

 

Do you have a magnetic drain plug? Check it for 'junk'. It sounds like you have some contaminants floating arond that are jambing up your OPRV - it dosen't take much to get it to stick.

Could be a sign that something is about to let go in a big way....

 

Update (from top)
OK, I replaced the OPRV with a brand new valve, replaced the thermostat as per Joshs suggestion, replaced the oil cooler seals while i was there, torqued the crank bold down again, rod bearings were replaced 10k miles ago. I STILL have low oil pressure. Light will flicker at idle, and once the oil is warmed up will not go over 3 bar. The oil pressure drops a little bit on boost (half bar). What are the other possibilities? Could the turbo be going on me? Will this cause low pressure? HELP!!
Also, I had a decent sized metal chunk (quarter of a pencil eraser) stuck in my OPRV when I took it out. uhoh. Any ideas?

 

It could be a couple things. Do you hear the lifters chatter at all (when the low oil pressue light flickers)? How confident are you in the gauge and sending unit? What oil are you running? Is the pick-up cracked? Can you move the crank front/back with a crow bar (thrust bearing check)? What shape were the rod bearings in when you pulled them. It's not very often that I've seen or heard of the mains being that loose....especially if the rod bearings were still decent. If you pulled big metal out of the OPRV, that ran through the pump and it is probably damaged.

 

Have you removed and inspected the oil pump itself?

 

Yes I hear lifter chatter when the oil pressure is low. I am confident in my guage and sender. I am running 10w30 castrol. I have no idea if the pick up tube is cracked. I seems odd that this would happen at the same time that the relief valve is sticking though, but who knows right. I havent tried moving the crank back and forth never heard of this. I could try that though. The rod bearings were shot when they were taken out but were replaced with new ones. Thanks for your input Jeremy

 

Nope, this requires dropping the pan right? I dont believe this was done when the rod bearings were done (a shop did it so I'm not sure). I have always heard the pumps rarely go bad though right?

 

It is rare for the pumps to go bad however if you passed a big chunk of metal through it (that you found on your OPRV) you without a doubt have some galling. Your oil is a bit thin and I would up it to a 20/50 if you're going to run dino.

 

yeah 10/30 good god! 15/40 at least man. Time for some 20/50w. I would drain the oil and have it checked to see what kind of stuff it in it. SOUnds like somethings floating around in there.