attyjeff

Ok this morning I was putting 134a in the air conditioner, I checked the antifreeze overflow and there was oil in it, soooo its safe to assume that the headgasket is gone, BUT its not overheating and is staying at the last lower mark on the temp gauge in stopped in traffic it might get to the middle but then the fans kick on and it goes back down? but anyway oil in the antifreeze overflow can not be a good sign. It might be blowing in under boost but normal driving not? kinda weird?

cheetah chrome

Oil cooler seals???

special tool

Could be slipping by the at the oil cooler seals.
How much boost do you run on that 48?

attyjeff

18 to 19 lbs, hey? maybe it might be the seals? it didnt do this at 16 lbs, maybe the added boost is pushing past the seal? man that would be nice, you guys are getting my hopes up now, how hard is it to fix the seals and are these the one on the OAS, where the fill the oil?

shiners780

Those are AOS seals, you want oil cooler seals:
http://clarks-garage.com/shop-manual/lube-01.htm

turboted

Your oil cooler seals and AOS seals are not the same thing. AOS seals (where you fill up the oil) tend to go bad and make a leaky mess on the drivers side of the motor, but won't cause oil/water to mix. The oil cooler housing is located on the front passenger side of the motor, underneath the oil filter housing. The two lines that connect to your oil cooler in the nose of the car are fitted to the oil cooler housing. To replace these seals, you must disconnect these oil lines, remove your oil pressure sender and oil pressure relief valve. Not a tough job...but frustrating to work around the headers. Make sure you use an alignment tool when you re-install the housing.

Geneqco

I know the 944s have an oil-water heat exchanger but I thought the 951s just had an oil-air cooler... or is that just the case with the 'S'? Can someone clarify please?

Thanks.

turboted

The oil-water heat exchanger is essentially the same on N/A and turbo models (in terms of mechanical concept). The difference is that turbo models have an external oil cooler located in the nose of the car, which the N/A models don't have.

attyjeff

I just talked to a another friend and he said the same thing that you guys are saying, the oil cooler seals.......man I was sooo used to the external oil cooler I was like "oil cooler" and coolent what are you talking about? but now I understand and I hope/think thats what it is.....it sounds like a real pain to clean the oil out of the cooling system, BUT I bet in short its better then a headgasket. thanks I will keep you posted when I get the seals in,

turboted

You might consider doing a leak down and/or compression tests before you decided to tear into your oil cooler seals. Somebody please correct me if I'm wrong, but I believe a leak down test will help you better determine whether your problem is a failing head gasket or leaky oil cooler seals.

If you DO have a bad head gasket, it's really easy to replace your oil cooler seals while you have the head off the motor. I would hate to see you replace oil cooler seals....then discover it was your head gasket all along....and have more work to do.

Geneqco

So do they have both the water and air oil coolers? Is this just the early ones because mine seems to only have the one oil to air cooler. Or have I missed something?

Thanks

sawood12

The water oil cooler is the block that the oil filter and oil pressure sender screws into. Inside the block there is a cooling matrix. The gasket that seals the block casing was leaking on mine and needed to be replaced last year. Incidentally this oil leak looked like it was coming from the lower balance shaft housing as the oil dripped down the side of the block and collected on the lower balance shaft housing. So if you ever get an oil leak from that area just double check it is not coming from your water cooling matrix housing.

turboted

Both N/A and turbo models have a water/oil heat exhanger mounted to the block of the motor (under the oil filter). On the turbo models only, oil is routed from this heat exchanger through an external cooler in the nose of the car (which is what I assume you are referring to as the oil/air cooler). Technically, the 'cooler' only exists on the turbocharged cars, while the 'heat exchanger' exists on all 944's.

Geneqco

I don't think the M44.52 have the water/oil heat exhanger... must just be the M44.51.

Tom M'Guinn

Hmm... on the N/A cars, the oil is cooled by the coolant inside the oil filter mount housing (i.e., oil cooler housing). On turbo cars, the oil is routed out of the oil filter housing to a separate oil cooler, which uses air flow to cool the oil. See pictures and detailed R&R instructions for both the head gasket and oil seals in the link below (along with tips on distinguishing between the two problems). Having done both, I'd say it's a coin flip as to which I'd rather do yet again.