pnbell

Hey guys, this weekend I replaced my oil cooler seals -it was not that fun..- I only did this as a precautionary measure.

Anyway all is back together, runs good, oil pressure actually seems to stay higher, but at startup my oil pressure takes way longer -than it used too- to raise and I can hear the engine tapatapa tapa for like 3 seconds....

Any thoughts, new Mahle filter, 10-40 dino oil, car runs and idles fine; just this startup issue....

87' 944 na, 170k miles,

krazykarl

My first thought is maybe the check valve in the oil filter is defective and while the engine is off it's draining out. Another possibility is the OPRV isn't quite seated properly and oil is leaking past as well.

L8_apex

When remounting the cooler, did you replace the o-rings on the oil pressure relief valve (OPRV)? There are o-rings both internal and external on the OPRV and defects in either can cause slow build up or fluctuating pressure. (Thats why the tapping sound - not good) For an '87 I think you should have the later, one-piece OPRV. On that, only the external o-ring can readily be replaced. The rings are cheap and available at the ususal 944 part suppliers. When the OPRV is out check that the center plunger moves in and out smoothly with moderate resistance. OPRV mis-alignment in the cooler housing can also make it behave strangely - it has to turn in VERY easily by hand almost to the last turn.

I_am_imprezed

why are you using 10w-40? just curious

Reimu

This problem crept up out of nowhere on my car. Its an early 87 I think because the oprv is the older style with the non captured o-ring on the tip.

I've changed the oil, tried a new filter, checked the oprv and it seems to function fine, then I loosened all the bolts on the oil cooler plate and torqued down the oprv before retightening them. So far nothing has worked and I fear it may be damaging my lifters because they're starting to get noisy, like embarrassingly noisy.

Van

Could be your head check valve?

John_AZ

RL member Massive has OPRV information and pictures.
http://944foot2thefloor.blogspot.com...-oprv-oil.html

There are 2 "O" rings that should be changed.





The late OPRV requires an alignment tool to prevent binding if the oil cooler housing is moved.
If you are just replacing the OPRV inner and outer "O" rings, and not moving the housing, it can just be replaced.

J_AZ

Reimu

Replaced both OPRV seals and the problem persists. Most peoples head check valves seem to fail to closed but I guess that along with a crack in my oil pickup/leaky oil pump are my only real possibilities.

alex_cristocea

I'am courious if you have solved the problem. I have the same problem as you since I changed the oil last week (castrol 10w60 and Mahle OC142 oil filter). I changed the filter yesterday and no change. I changed all the oprv seals last year.