Porsche Enthusiasts Club Forum

Hi all, So my Oil Cooler/heat exchanger housing has had the usual seap down the block and around the power steering pump area. I cleaned it off and confirmed it needed to have its gaskets replaced so I ordered a set. Stripped off the manifold, took the housing off cleaned up the old bits of gaskets, changed the plastic washer and cooler O rings, measured the shim all ready to install back.... however upon stripping my Oil Pressure Relief Valve (should be a one piece long one) the cap and spring came off and the little bar came out, the piston is still in half in the block and the external O ring is shot.

I m struggling to find replacement O rings... part number
999 707 144 40 do people know the dimensions to source alternatives than buying a complete OPRV new from porsche at great cost?

Or would it not be better to sell the OPRV seals and outer washer in with a housing gasket set?

just go to Porsche dealer for them

you wont want a new 1 piece OPRV

O rings 999 707 144 40 direct from Porsche £1.52 each inc vat

OPRV 944 107 035 02 £376.48 Inc Vat, but if you have the housing off, Replace

951 107 152 04 £8.64
and
999 707 043 40 £1.52 x 2

the cross tube and seals, you will need a tube as you can easily butcher it getting it out

Many thanks, Mine is the 2.7 M11/12 so it has the matrix with the plastic washer/ 2 O rings in the gaskets kit along with the main outer gasket.

I ll ring up my dealer and see if they will post them out to me for the sake of driving an hour from mid Wales if they have them in stock.

Like I said it would be easier if they provided new o rings for the OPRV knowing its got to come out and get re aligned if the housing is fully off.

Have you got the alignment tool?

Yes, I ve the tool, I m just more concerned that my valve has unserviceable O rings and was in 4 bits when I took it out... Cap, spring, Little bar and the main piston stuck in the block,lol

Picked up new O rings and Sealing ring from dealer yesterday, only issue I have now is still getting the OPRV main tube out

That looks expensive

I'm guessing you removed the housing without first removing the OPRV?

Wrap plenty of rags around the shaft and you will have to try and pull it out.

There were two types of OPRV but yours being a 2.7 should be the later style OPRV with a 24mm head? (early style is 17mm).

I found these links useful when resealing mine -
https://944foot2thefloor.blogspot.com/2 ... v-oil.html
https://www.porscheclubgb.com/forum/tm.aspx?m=912809

It is definitely servicable as long as yours hasn't got damaged (might be able to get a good used one from a breaker / ebay).

I stripped mine as the o-rings were brittle and snapped, replaced with new ones (you can buy an oil cooler repair kit from several places - not sure if it includes the o-rings for the OPRV or not...)

Put a 10mm rawl bolt fixing down the inside, then use it as a puller

Don’t damage it as I have heard they are very hard to get or nla

Nice method right there

Not sure if it is liquid but it appears that someone has already had a go at the end of it with some pliers or similar?

The tube is showing in stock at opc

951.107.152.04 £8.64

2.7 is NA isn't it? doesn't use the cross tube as it has the built-in oil to water cooler.

yep you are right, that's half the OPRV stuck in there, and now ruined,

looks like you might fit a 8mm down that, its gotta come out now no choice..............................

and its not cheap

1986>> 944.107.035.11 £323
1987>> 944.107.35.02 £376

You can put it back together as long as it hasn't been damaged and you still have the spring (see the first link I posted above for assembly instructions).

End of that tube is very damaged

Some used ones for sale on ebay from £75-£150ish