fourniem76

Good day eeveryone,

upon rebuilding my 944 motor, I noticed that the piston in the oil pressure relief valve is REALLY REALLYhard to push back...as a matter of fact I had to hamer it back...in my experience with such devices with other engines, the piston should move freeely, and the spring behind it regulates how much it moves, hence the oil pressure.... is this something that is kniown to go wrong on 944's ??

Thank you,

Michel.

Crippler

there are two types of oprv's. The early ones which consisted of three pieces and a revised model that was one piece. The early ones would tend to build up corrosion and stick after awhile(yeas they are supposed to move freely) I had the corrosion problem with mine in my 84 944. I decided just to polish and coat mine in anit size rather than buy a new. It has worked very best for me ever since and saved me some cash. So your first step would be to determine waht one you have.

Danno

Uh, did you remove the oil-filter housing? There's a special alignment tool to make sure the outer half of the hole in the housing is lined up with the hole in the block. Why Porsche didn't put two locating dowels on the housing, I have no idea. Another Hans & Frans evil-engineers' trick!

Perry 951

And if it was so tight you had to hammer it in... you may have messed up the brass busing in the block. Make sure you check it very well when you take it back apart. If that busing is scored, you need to replace it, and that is about impossible with the motor in the car.

Your '86 has the 3 peice valve. (piston, spring, cap) The piston should move very smooth. Since it does not, make sure there are no debris in the bore, and the piston itself has no score marks on it. If it does, you have 2 options.

-Replace with a new 3 peice valve
-Buy the new 1 peice updated valve (not the same as the '87 and later valve)

As said above, once everything works as it should with the housing off, make sure you align the housing with the alignment tool when you put it back together, or you'll do it all over again.

schlag

Who has the best price on the 1 piece updated one?

Perry 951

Bump... and not sure on best price. They are $300+

Your '87 should have the 1 peice.

fourniem76

actually it was a 3 part valve ... I took it apart and polished the piston & inside of the valve until it slides freely... so I assume that to increase oil pressure, I can use the usual trick of shimming the spring or putting a stronger spring ....I'll try that I think...

Thanks to everyone..

Michel.

Perry 951

Mike... sorry for the confusion... as you know, your '86 has the 3 peice.

Schlag, your '87 should have the 1 peice updated valve already.

schlag

Interesting. I'll have to have a look in there again.

I too am trying to get to the bottom of the "delayed oil pressure / low oil pressure at idle after warm" problem that so many of us are having. :|

fourniem76

I am not that familiar with Porsche engines... actually my first time working on one. I have not touched the '86 yet...it has high mileage but runs without problems... the '87 engine was just rebuilt....by myself..had the head slightly worked, a ported intake manifold, and lightened crank & flywheel.. I did have some problems putting the oil/water unit back in properly ...it took a while to get it aligned properly.... But the valve was stuck when I dissasembled the engine... as for the actual history of the car... don't really know... for all I know, it could have a different year engine...