Engine swap almost done
 

Well I'm almost done with the engine swap in my wife's X-type. Once I got the cooling system all reinstalled I added the antifreeze mix and of course I had leaks. I was suspicious the radiator was seeping but it was worse than seep. It's dripping. I also had small drips where the thermostat housing attaches to the water pump housing on the head.

I removed the radiator again, with extreme prejudice, and broke one of the end caps. It was pretty brittle. I should have known better than to try to reinstall a 10 year old questionable plastic end cap radiator, but hope springs eternal, I suppose. Hope, and several hundred dollars.

So the radiator is an easy fix, just add money. But the drips at the thermostat housing have me more concerned. With the rad out of the way, its an easy reach to the thermo-housing. There was some corrosion at the "O-ring" (let's call it, not really an "O", but for ease of discussion...). I polished the metal side with some crocus cloth and scotchbrite, and it looks pretty smooth, but I am not 100% sure a new O-ring is going to be enough to seal it.

Has anyone used any gasket compounds on the thermostat housing to water pump housing joint with good luck and if so what kind did you use?

Picked up a new gasket at the dealer. I think its the first part I've bought from them that they had in stock.

One thing to remember when dealing with these plastic parts is: don't over-torque it!
Check the torque spec for the bolts. The housings easily flex and can cause an
otherwise good part to leak.

Pete.

That is true, and thanks for the reminder. Forturnately metal inserts in the stud holes in the plastic housing help prevent a lot of oop's, but they aren't failsafe.

The engine that went in, I bought from a dismantler so I don't know its history other than it is purported to have 60,000 miles on it. So any latent problems it brings to the party I have have not seen yet. Hopefully this coolant leak is the glitch for this mission. We'll know next week. I won't get to touch it again until next weekend.

I've been transfered back to our home office in Texas so I am not working in Alabama where the car sits right now. I have told my wife she will be able to drive it from Alabama to Texas under its own power when she moves this summer, or it will have to go the happy X-type hunting grounds in Dixie. I've done all I can do for it.

Still wondering about gasket compound on the thermostat housing to water pump housing? I don't want to add it if I don't have to, but I sure don't want this to leak again.

I always have good luck with silicone gasket cement. It works well on coolent joints.

Pete.

Needs to be the acid free type if you put it on aluminium.