ButtSled

Hey all, I am in the process of replacing my cooler housing as the OPRV threads are stripped. Here are two pics. Can anyone explain the differences again? Also I hear alot about two o rings. Is that the aluminum sealing ring and one "regular" oring or am I missing a ring say up by the shoulder? Many thanks all. And yes, this time I have the alignment tool. That is how the old housing's threads got stripped! Is the OPRV in the second pic look ready to install? Later dudes and dudettes.


Dean Felton
Houston TX
83 944

Tom M'Guinn

There is another o-ring inside if you pull the cap threads off the shaft part. Probably not worth the risk of dissassemly to change the inner o-ring.

Can't tell from that picture if you have the o-ring installed on the end.

Clean that valve off before reinstalling it -- don't want carpet crud in the motor oil.

Granite 944

Ahhh..........I'm not sure here, butt, after reading what ya said about the "stripped threads" and looking at the OPRV that is in pic 2, I'm a thinking you have the wrong OPRV there. This is suppose to go into the '83, I take it? Normally, the early "1 pc" OPRV is quite distinguishable by the threaded cap that has what looks like a taper in the beggining of the threads. The early style 1 pc is also shorter than the later 1pc. They are NOT interchangeable. Please, give us more info regarding this OPRV. Did it just recently get replaced? A closer up pic of just the OPRV would help. I suggest you do not proceed till these questions are answered, or you may have another "stripped out" problem?

Tom M'Guinn

I'm pretty sure the threads are the same on all 3 styles of OPRV's.

Granite 944

No..........I don't think so. Not from what I've seen/experienced. Fig. A is the "early 1 pc".......Fig. B is the "later 1 pc". Then there is the difference in the "later 1pc OPRV's" in the material that they were made from......thus having a recall on them for being made out of the wrong material, and thus corroding really badly. Thats another story, and TSB. alldata.com. Worth the money to suscribe.

I SURE could be wrong. I've been there before!

Granite 944

I agree with this. It can be very hard to get this outta the cap if your not VERY carefull on how you approach this. Butt, it ya do...........this is what it should look like dismantled.

IF..........you are gonna re-use this particular "1 pc. OPRV".........change Both O-rings, and make damn sure that the bushing that it fits into, which is in the block that this OPRV rides into, is VERY solid and secure. NO movement allowed here. Make sure it is fully seated/straight/solid. Locktite it IF neccessary. Sandpaper is a bad idea for cleaning OPRV's and or bushings. Scotbrite, is my suggestion (MUCH more important on the early/3pc design).

Tom M'Guinn

I'm a big fan of alldata -- the valves are different for sure. I think the thread diameter and pitch is the same (though maybe not the depth) even though the shaft is a different diameter. I think I have one of each in the garage -- I'll check to be sure. Don't quote me yet...

KuHL 951

Maybe this is second nature to most of you guys but I thought it might help to post the part numbers for the o-rings on the two styles of 1-piece OPRV's for those of you with OPRV issues. I went through the no OP buildup problem last year and dumping the 3-piece and swapping out to a 1-piece early conversion with new o-rings did the trick for me at least. Kevin Baker helped me alot on this problem.

From the bulletin these are the replacement part numbers;

83-86 944, 944 turbo
1. Valve is 944 107 035 11
2. O-Ring is 944 107 935 11
3. Seal Ring is N 043 815 3

87+ 944, 944 turbo, 944S
1. Valve is 944 107 035 01
2. O-Ring is 944 107 935 01
3. Seal Ring is N 043 815 3

The OPRV differences can be seen in the pics:
1983-86 OPRV (including 86 turbo) conversion unit:



1987+:


The early 87 OPRV with corrosion problems were pulled within the 1st few months of production and have probably been changed out on 99% of the 87 cars by now.

Just make sure your OPRV matches the year of housing you stick it into.

ButtSled

Thanks for all the great info people. I figured the one that came with my new housing was a later one. (since it would NOT fit) I just changed back to the old one. Changed guts to the new screw. Screwed in nice and smooth. Got my new 10 bar sender hooked to my new (87 924) 10 bar gauge and get a nice 5> on startup 2> hot idle. Now to just finishing bleeding the cooling sys. Again, thanks for all your replys.

Dean Felton
Houston, Tx