Hey folks!

I'm working on my spec car bit by bit to get me through HPDE and prep to enter spec series in some time. Anyway, long story short is I wasn't happy with oil temps when pushing hard on a hot day, so I decided to go for the 951 external cooler.

Got the new cooler in and couldn't get oil pressure. Turns out the 951s have a guide tube (like www.944online.com/cgi-bin/ASI_Store.cgi?...ct+skukey_1220372811) that my cooler didn't come with. Oil/Coolant mixing, bad. Flushed the sucker six-ways from Sunday, got myself a guide tube, took everything apart and put it all back together again.

Now I've got oil pressure (wahoo!) but the water is stll getting tons of oil in it, and I'll be damned but it looks like the oil is still getting water in it to.

Any thoughts on where I might've goofed?

(Also, x-post'd with 944online; www.944online.com/cgi-bin/forum/forum.cg...splay;num=1371356321)

It will take a long long time to flush both systems. Had that happen on a turbo when the head gasket let go and caused two way mixing.

The oil in the cooling system will be there in small deposits for months.

The coolant in the oil should clear quickly as you run the car and allow it to steam off.

Right -- my problem isn't clearing the system, its preventing further mixing. I do not know for sure where its coming from or how to fix it ;/. One theory is the "2 o-ring channel guide", another possibility is a blown headgasket (but the timing on that would be really coincidental). Any other thoughts?

How do you know you are still mixing and not just seeing the residual mixing?

Did you lightly surface the block and the oil cooler housing before install?

I use a Redline spray on gasket sealer on those to help take up any small imperfections. I also do that to the headgaskets and cam gaskets too. Not sure this is the issue but it might help if you pull it apart again.

Did you use the special guide tool when you assembled the housing to the block to line everything up?

Did you use a TQ wrench on the housing bolts in the torque sequence when you assembled?

Did you buy new hardware for the cam housing or reuse old bolts? If so there might be some bolts bottoming out in the block (too long) and not allowing for proper internal sealing (seen this one myself). They look fine but were a few mm too long and TQed down but not on the head of the bolt only the threads bottoming.

Good luck!