Eyal 951

I'm having a high oil pressure condition. Its been going on for quite a while. The gauge pegs sometimes, sometimes it hangs out right around 5 bar, and it jumps around sometimes. Sometimes it will go hang out where it should be, but very jumpy... it can peg, then be at 3 bar, and 5 bar and back to 3 in a second or two at idle. this could go on fora while. Sometimes it will hang out at 4-5 bar at idle.
I though since all the movement, it looked electrical. I replaced the sending unit with a brand new one. Same deal. So I figured OPRV. Well, I bought a used one. which took a LONG time to get here (through no fault of the person I bought it from, thanks Todd!) . I tried driving the car minimally, but i did blow TWO oil filter gaskets during that time, finally today i got the used oprv I bought. got it in (it was quite different then the one that came out) and started it up and drove. It pretty much does the same thing... maybe a tad less, MAYBE. Could also be my mind. Am I facing something else? hopefully not big! or you think the OPRV I bought is bad too? I probably should buy a new one. If its something else, I really dont want to spend the 270 bucks when i have 2 good one. Anyone have a used KNOWN GOOD oil pressure releif valve I can buy or borrow for testing?
~Eyal

streckfu's

I hate to bring up grounds but it still seems electrical to me. If the OPRV failed closed, Iwould think it would stay high while if it failed open, pressure would stay low.

hosrom_951

Did you try hooking up a mechanical oil pressure gauge and observing the readings? you may still have electrical issues (maybe).

Did you clean the OPRV and get new seals for it as well?

Eyal 951

I have blown TWO oil filter seals. Its def high pressure which means not electrical! Otherwise I would agree with you.
Hos, I did clean em very well, and did put in a new o ring. I cleaned with Sea foam deap creep... should do the job.
~Eyal

hosrom_951

Eyal: You are most prbably right about the oil filter seals blowing due to the OPRV, i THINK you have to have a special alignment tool for the OPRV?? i know the oil cooler housing requires it for critical alignment, so is the bushing as well???

Eyal 951

I have never installed it by aligning it, but I dont beleive the 87 plus ones need alighnment. If they do, I sure will feel dumb!
~Eyal

jwl

To find out it's electrical or mechanical cut off the base of your old sending unit and drill and tap to 1/4" NPT. Then you can plumb into the oil filter housing with a series of 1/4" fiitings, pressure hose, and 100psi gauge. Make the hose long enough for the gauge to reach your wipers. Run the car and watch the gauge...if it jumps around it's mechanical...if not it's electrical.

hosrom_951

Eyal: I came across this on Mr. Bruce's website:

"Above is a service receipt for a classic Porsche 944 problem. The engine had been completely resealed a few months prior (at a cost of $1750.00) when this problem occurred. How can this happen? It's easy - just neglect to get the cooler housing aligned properly and sooner or later the oil pressure regulator ("pressure relieve valve") sticks. Oil pressure goes to max, which then blows out the filter seal. Rapid loss of oil causes oil pressure to then go to zero. This could have been much worse, either the engine could have seized (rom lack of oil) or the leaking oil could have been ignited into a nice smoky fire."

Did you remove the oil cooling housing for a seal job some time ago?

Tom M'Guinn

They do make an alignment tool for the 87 OPRV. Check that the OPRV slides in and out easily, and that the threads turn in without resistance. Otherwise it may be binding.

How was the new (used) OPRV different from the one in there? Was it the same size/length?

Eyal 951

1) I Did reseal the oil cooler housing recently, and did not align it I dont think. Whats required to align?
2) Tom, They were different size and length's and the plunger was a different design. It was quite different. Also, int moved at the base where the thread were, this one did not.
~Eyal

hosrom_951

The oil cooler housing must be perfectly aligned when installed, once it is taken out (for re-sealing). I believe that could be the problem you are facing.......

Eyal 951

how does it get alighned? And must I redo the job to fix this?
~Eyal

Tom M'Guinn

The alignment tool is just a drift the slides into the port while you tighten the housing. It is more important with the old three piece OPRV's, but they do make a tool for the one-piece units, and Porsche's TSB says to use it to prevent internal binding in the OPRV.

There is only one (size) OPRV for the 87. I wonder if the one you put in was just partially disassembled? The hex head part pulls off the shaft on the one piece units (and there is an o-ring to put in under there). In addition to the alignment, if it is apart anyway, you may want to check that the plunger slide freely inside the shaft without hanging up anywhere.

hosrom_951

You need two tools for proper alignment.

-Alignment tool for oil cooler housing to block (courtesy of Mr. Bruce)




-Alignment tool for OPRV Bushing (944 Manual)



I don't have the first hands experience in the alignment, nor the oil cooler seal job, but i can tell you that i was extremely pickey with the mechanic for having those two tools for doing the job.

So, i guess you need to re-do the job, sorry to say. I think Danno has the tools, you can rent it from him?? ask for his view? (he is close by you right?)

Eyal 951

I just got off the phone with danno (who happened to help with the reseal) and we did align it using the OPRV itself. I geuss this is why it is aligned, so that the OPRV can go in.
~Eyal