jmj951

You've definitely found your problem and the solution is - without a doubt - to get the newer connector pipe. You do not want to have to reseal this again with the engine in the car. I was unaware that there as even an old style connecting pipe, and the pics you posted of the pipe with only one o-ring were driving me crazy all weekend. I finally went to 944online and found an exploded view that shows two o-rings. I'm guessing that my car had this pipe replaced long before the previous owner, because when I had to replace the o-rings it definitely had one older one and one newer one.

Also, I really recommend cleaning that housing. Those surfaces are not going to seal up well.

KSira

A little update. Used some loctite 574 on the pipe, let it sit over night and now the coolant system has held 20psi for 2.5 hour.

KSira

Fired up the car and now it is not holding pressure any more Will try with the new connecting pipe when it arrives. Could it be the gasket around the housing itself that leaks?

refresh951

I am concerned something else is going on. So coolant held 20 psi for 2.5 hrs cold, then you warmed up the car, tested again and it did not hold pressure? If so, I am concerned about the head gasket.

Is the MLS brand new or did you reuse it?

KSira

The MLS is brand new. Found a small leak in a hose, fixed that and the pressure drop rate slowed considerably. After that a fall from 21 to 19 psi took 16min. Let it sit overnight with 21psi, and this morning it was just above 15psi.

Did also check the coolant pressure build up on a running car, and got 20 psi pressure build up.

Thank you, and everyone else that contributes for the help!

KSira

Finally some good news. Problems is solved. No more milkshake! Have flushed the cooling system several times and used some some expensive soap thing that seemed to do nothing for oil contamination.

Need to sort some minor thing out and then it should be ready for mapping. I am very exited to see what a 16V Turbo will do!

refresh951

Great to here!

Chris White

The 968 parts are different than the 944 turbo or NA parts.
BTW - it might be a little late....but I usually block off the coolant flow from the block to the oil console - it does not do anything for a 944 turbo or 986. blocking off the ports in the block will help to eliminate a possible leak source.
BTW2 - the coolant does not 'flow' through the expansion tank, only the turbo coolant has a circular route through the expansion tank - so it is not a good indictor of what is actually going on inside the coolant system.