Kevin Baker

OK more information on the problem.

When the car (86 N/A) has been sitting for 2-3 hours, the oil pressure will take 20-30 seconds to build. I keep shutting it down after 5-10 sec of no pressure, and restarting. After about the 3rd start, it build instantly.

I have a Mahle filter, and Castrol GTX 20-50.

I'm changing the oil, and filter tomorrow. I'm changing to Castrol GTX 10-40. I think maybe the 20-50 is too heavy cold to circulate. Or worst case, the OPRV is sticking.

Any thoughts?

ahofam123

I wish that that was the worst case for mine. I cleaned the oprv twice but the problem still persisted. I then dropped my crossmember and oil pan per my mechanic's suggestion to see if it was a cracked pickup tube. I found that the pickup tube was intact but I found that the seal beneath it was the wrong one. After I get my ball joints in I will reinstall the cross member and let everyone know if the new seal corrected my problem. I hope that your delayed oil pressure is fixed by the oprv like others' have been.

944ZEN

I also had the Delayed oil pressure after i changed all the seal's and the oil pan seal. Like Ahofam123 i cleaned the oprv twice, it helped a few days but then the probelm returned.

But. 3'rd time i didn't just celan it. I used som 1200 grid paper to grind the surface off the OPRV piston, and used it inside the OPRC cylinder. I used a screwdriver faced with a soft cloth to clean the mating edge in the bottom off the OPRV cylinder. Then i used compressed air to blow away any "leftovers". I oiled up the resurfaced OPRV and put in. And the proplem has benn gone since, this is 6 week ago now.

Kevin Baker

I think (hope) my problem is related to the oil and or filter. Porsche recomends Mobil one synthetic which I belive is 5-30 or something. My problem started a while after I changed the oil I think. Before the oil change the PO had been using 10-40 and I changed to 20-50 for the summer. I'll be changing back to 10-40 and I'll post back after with results (good I hope). If no good, I'll be tearing into the OPRV

Luis de Prat

Main reason why I haven't fitted my spanking new Canton performance filter yet. I hear it's a bear to build up pressure on cold startups.

Kevin Baker

Well, changing to a lighter oil did not do the trick, nor did changing the filter. When it is cold (not run for 2 hours) it will take 20-30 sec to build pressure. I guess I'll have a look at the OPRV on Sat. Until then, if I pull the DME relay, and crank with the starter until the pressure builds, then replace the relay, and start all is OK.

944Targa-fan

Kevin,

We have the exact same problem, I changed my oil from 10W40 to 20W50 and now I have 0 oil pressure. I also think it's the OPRV.

I'm planning to check the OPRV this weekend, if you found the problem and fixed it before then I would like to hear what you did.

Thanks.

Kevin Baker

Nope. Still there, let me know what you find w/ the OPRV. I'll keep checking the thread.

944ZEN

Kevin when you say "checking the oprv" what do you do exactly, since i thought i did that to (twice) and i even cleaned it all, but "still no cigar". It was the 3'rd time, when i got a little more agressive with the 1200 grid sanding paper, and clean rags, and compressed air, that i got a result. I'm thinking of running some oil cleaning agent stuff before next oil change.
My theory is that this is cause by some old oil-gunk, like the one you can have from petrol in a carburettor. And some off it might travel to the OPRV and make it stuck in an partly open position, thus the trouble building pressure.

johnjcoyle

Hi guy's,

I have a 88 N/A over here in Belgium. I had a big problem with the oil pressure and discovered that it was initially a completly cracked into 2 pieces oil pick up pipe. It used to bo OK on a straight road and then when I went around a corner it would rattle the lifters like mad.....

Anyhow, I had my mechanices over here ( www.v-zweeden.com also check out their spares availability it's great with shipping world wide.) drop the sump and do the new pick up pipe, after this the problem went away.

Now I have good oil pressure and no noise at start up when the engine is cold, after it has warmed up the lifters make a little bit of noise and the pressure is artificially high, so I am going to do the clean up of the OPRV and I am sure this will cure the noise problem.

I am on my 2nd OPRV, the one in there now is brand new but its the second time I have put it there, the first time I bought a new valve from a porsche dealer it was from bad stock and did not work properly.

So now I am going to clean up the original OPRV with your methods and put it back. I am sure I have wasted some money buying a new OPRV..

I will keep you informed of the progress, and by the way, do any of you have lifter noise with this issue ?

Regards,

John C Brussels Belgium 1988 N/A Alpine white.

Kevin Baker

Yes lots of lifter noise.

TaboII

Just my .002 guys, but I would be very careful using any oil scrubbing agent or cleaning agent. These cars don’t like a lot of that stuff and some of it can actually cause damage. If I remember correctly some of the more experiences mech will not used this kind of cleaning chemicals because of the risk of damage to the engine.

Just be careful

TaboII

ahofam123

Perry951 suggested that I use the Rislone oil additive (might be called Rosline, I don't remember) to clean my oprv. It didn't solve the problem on my car but it is worth a shot. I believe that the local auto parts store carries it for around $2.

bearone

too cold in Houston in the summer for 20/50, i don't think so.

MHT

Luis, recommend against the mecca filter, the check valve, rubber flap, in those filters do not work, every start will be with an empty filter housing and no oil pressure untill it fills up.