I have a 2005 2.5T XC90. The heat has been working terribly and I pulled a few codes indicating the thermostat was bad. I dove into the project tonight and I'm stuck.

Volvo in their infinite wisdom decided that torx bolts were a good idea. They also decided that replacing the thermostat involves a whole housing and not just a thermostat. The top bolt came out great. The bottom one, the blind one...the one you can't see is stripped. Short of removing the engine from the car I have no idea how to get that bolt out. Getting a grinder or drill in there is pretty much impossible.

No problem I thought. I'll just leave the lower housing there and replace the outer housing. So I took apart the new thermostat housing. The gasket of course stuck to the wrong side. My attempt to get the gasket off the new housing ended in a mangled gasket. Cool.

So...any ideas?

I'm thinking about just getting some gasket material and making my own and sticking with my idea of just replacing the outer housing. You can easily find the gasket that goes between the housing and the engine. The one that goes between the two halves of the housing...yeah, I can't find that anywhere.

Or, what about the gasket in a tube stuff. Good or crazy?

Also...the thermostat itself has a brass nipple on the rubber edge. The way the thermostat goes into the housing means that nipple is either on the top or bottom. Anyone know that answer to that one?

LOL...this is a mess. I throw myself on the mercy of the forum.

 

A bit more info...

My current plan is to leave the bottom part of the housing on the engine - the old one with the stripped bolt head.

I'm going to try to salvage the torn gasket that goes between the bottom and top halves of the new thermostat housing. So I'll have the old housing still stuck to the engine, the new outer housing mounted to that, and use the torn gasket with Permatex RTV thermostat gasket stuff. If this makes no sense, I get it. It's my project and it's confusing at times.