Chipster

Recently, I decided to replace a leaky oil pan gasket and the rod bearings on my 86 951. While I was draining the oil, I noticed a small amount of coolant in the oil. A quick check of the cooling system showed no sign of oil contamination, so, after some research, I determined I had a leaky seal in my oil cooler that was allowing coolant to seep into into the oil.

As you may or may not know, the 951 has an external oil cooler, as opposed to the internal cooler found on the N/A models. Instead of an oil cooler housing, the turbos have a cover plate with connections for hoses that go to and from the external cooler. The oil cooler seal kit comes with seals for both types and you simply discard the parts you don't need.

For the turbo, the only seals you need to replace is the large seal for the cover plate and the 2 seals that go to the small cooler pipe that protrudes from the cover plate.

When I did my re-seal, the reference I had didn't mention removing the cooler pipe to access the second seal, so I replaced only one. So, after putting everything back together, I fired-up the engine and after a few minutes, I noticed oil leaking from one of the oil cooler hose fittings. After I shut the engine down, I also noticed the oil was a nice double-latte color. Something was obviously wrong.

Another quick check of the cooling system showed no oil contamination, so I knew the problem was again in the oil cooler.

While not a particularly fun job, removing the oil cooler plate with the engine in the car is doable with the proper amount of cursing. The hardest part was removing and installing the f-ing heat shields - and of course all the oil, coolant and PS fluid that drips on your head. A big thanks goes out to Tom McGuinness on his write-up of this procedure.

I also learned that Porsche updated the oil pipe to help prevent leaking (951 107 152 03), so I ordered a the new part and replaced both seals. The picture below compares the old and new pipes.

The engine is now back together and running well with no more leaks.

Hooah.

SamGrant951

Hmmm, interesting. I replaced those seals on my motor and didnt even know about the upgraded part.

Anyone know what year the change was made to that piece?

jerome951

Idiot!!!! ;-)

I never go into my car without reading Clark's procedure and any post on Rennlist related to the subject. I usually spend 3 hours researching a 1 hour repair.

Agreed, the engineer who designed the heat shield mounting system should have been fired... then shot.....

xsboost90

hm- new updated parts huh? Well maybe next time its apart.

Cory9584

i need one of those, then again i need the whole housing since mine stripped out

Cory9584

can you measure the tube? Im not sure if mine is updated or not and theres no p/n

Chipster

I'd measure it, but it's bolted into my oil cooler - and I REALLY don't want to do that again. I think it cost me $11 at the dealer.

Jerome - I am an idiot, that's why I have to do these things twice.

I spent many hours researching this one.

Actually, Clark's write-up only says to change one seal on the turbo. I sent them a correction, but the email got kicked back.

Cory9584

can you measure the old one?

Chipster

Cory, the old pipe is 21mm. I think the new version might be the same length. The change is in the location of the seals. If you notice in the picture, on the old pipe one seal is located closer to the end of the pipe. On the new version, both seals are the same distance (closer to the ends). I think this helps the seals seat better. You should be able to tell which one you have by looking at it.

Cory9584

im almost positive i have the old one now that you pointed that out, i guess ill have to order one. thanks for the info

jerome951

My wrench or a friend must have reminded me to replace both seals as I knew the sleeve had to come out to replace the rear seal. The factory must have changed the part during the production run because mine was symmetrical like your new part.

xsboost90

mine was the old style and when i looked closely it fit further into one side than in the other. I installed the sleeve so the side further towards the edge fit into the shallower side and have had no leaks. I'd bet alot of these have been installed backwards.