xsboost90

got the car all together and she fires right up, BUT, when you do the oil pressure gauge flicks a bit then drops to zero and the oil filter gasket will blow and shoot oil onto the garage floor. WE thought it was the OPRV and changed that and put another Mahle filter on there and it blew it out again. Tried a generic STP filter and that one almost blew up completely! I cant see what the deal is, the OPRV screws right in very nice but everything has been cleaned, reinstalled and rebuilt so it could be bearings installed wrong at the machine shop, or anything! It must have great oil pressure cus the STP filter is all swelled up real big. any suggestions or similar experiences?????

Zero10

There is a blockage in the oil system.
The OPRV can bleed off excess pressure, but it can't handle the total flow of the oil pump.
That's my guess.
Anything happen prior to this? What work was being done?

xsboost90

i spun a rod bearing, installed another good crank-that has been polished and cross drilled- and new bearings. Block was dipped cleaned etc and everything re installed professionally. I put the rest together w/ andy. Seems like there is a blockage where the oil leaves the filter to the block but im not sure how that would happen.

ibkevin

Whooa, BTDT!

Eventhough we used the alignment tool to install the OPRV, we didn't use it when installing the cover! Re-check the alignment carefully, that thing balloons filter housings and rolls that gasket pretty damn quickly. And the mess sucks too!

xsboost90

im thinking -ok bear with me- its like 50degrees in the garage and the assembly lube is real heavy and in all of the bearing ports through the galley. WE are thinking that since its so thick that before it gets a chance to push the lube out and get oil down there, it builds up pressure and blows the filter seal. We put pressurized air through the center where the oil filter attaches and real slow it starts letting air flow but just alittle. WE are cranking the motor a crank at a time to try and get the oil to push the lube out and im putting a heater under the motor to warm things up abit.

xsboost90

well that was the problem now i need to install a new oil pressure sender since mine took a shi# and put my wheels on and bling bling to the car wash. THANKS!

Eyal 951

damn, wish my high oil pressure was caused by that.
Eyal

CARLVT

Yeah I had this problem on my son's 85.5 944. Blew out two aftermarket filters. Pulled the oil pressure valve which on this car is the first version. I could see two or three fine lines on the valve body. They would just catch a finger nail if you ran it over it. Not wishing to pay of the new version and the alignment tool I made a paste of very fine abrasive powder and motor oil and spent about
20 minutes working out the lines in the valve. Cleaned it up, put it back together and used a Mahle filter. Its been fine for 2000 miles although pressure still pegs the needle on start up but drops to 2-3 when warmed up at idle.

KuHL 951

Still haven't found the problem? That must be frustrating to go through all the known causes and come up empty. This all happened after the Danno headwork right? There's got to be a blockage somewhere, at least you don't blow out filter seals so you are getting some flow.

xsboost90

there is a valve in the head under the back of the cambox that regulates pressure to the top end. I would bet its stuck or something unless youve already tried that. Prob. w/ mine was the top end was getting oil but the bottom wasnt...we heated up the block and cranked the motor a bunch w/ the spring out of the OPRV and it kept from blowing the filter but washed the bearings out real good. Then we reinstalled the spring and all was good. Definitly not the OPRV malfunctioning but too much pre-lube clogging the oil ports causing an overpressure that blew the filter before it cleaned the stuff out. Just cant wait to tell the machine shop about that...

joseph mitro

too much pre-lube? it must have been soaked. i used a lot of lube on my bearings and never had any problems.

KuHL 951

I don't think assembly lube could cause this problem. The valve in the head is a check valve to keep oil in the lifter area (cam tower) from draining back during cold start. If it fails doesn't it just shunt oil through the head? It's not like a blockage if the CV fails closed, your lifters will just clatter like crazy but oil pressure should be fairly normal.

Eyal 951

its happened before the head. I really have not touched the car for a while. everyonce and a while, i go out there, touch it a few times, check one or two things, (oprv, grounds, filter, contacts) i mean, working on the car is a bitch, which is ok, but not when nothing ever gets fixed, or you did more harm then good (last thing I did, which is why i havent touched it in a month now) I cleaned my contacts in the gauge cluster which did NOTHING but turn on the f*cking airbag light. (had to remove wheel) fine, just jumo the lead like any other car right? hell no, buy/make a damn tool with a switch....
I can say the issue is far better then before, it no longer blows gaskets, its even fairly normal when cold. Next, replace oil cooler and inspect external oil lines for kinks... probbaly soon.
Eyal

Kevin Baker

I had a similar problem due to a clog in the oil cooler. The o-rings on the cooler to housing/block failed and the resulting goo clogged the oil cooler. Which then gooed up the oprv, and blew out the gaskets on a couple of wix filters. Resealed the cooler & housing, changed the oil twice within 30 minutes of operation. No problems (knocks on wood). Oil pressure has been a bit high at cold running 1500-3000 rpm, but drops down to 3.5-4 within 15 minutes (idle).

ibkevin

I'm with Joe Mitro on this. If there was that much pre-lube even at 50deg it would really take a drag on the starter motor while cranking.

"Then we reinstalled the spring and all was good." I think this is where your alignment got corrected.