left-handed drill bit on stripped t-stat T40...

[xHeart]

...its as good a having a factory hex head on the shank. Then just use a socket wrench or box wrench and turn the stud out.

Ozark Lee advocates hex bolts, I asked the Volvo parts if there is a matching bolt with hex that I could use instead of the T40 on t-stat housing. Only thing I got was a long stare.

It was only possible because Lee, cn90, and you were there cheering in absentia.
You can do it.

I've been out of town all weekend, but I'm glad that you got it fixed. What's next on the list to tackle?

MVS Mavericks pointing me to PCV. I am slowly taking control of its vitals. It is making more sense each time I read a post from fellow DIYer.

Are you planning on fixing yours?

[xHeart]

I was at Advance Autoparts today and happened to see that they sell the Long Torx set.
About $9.95 for the Long Torx Set.

A must have tool for T40 on t-stat.

[JimBee]

It's definitely good to have that long T-40 in your toolbox. But even with that those torx heads sometimes strip out. If the torx well in the head is clean with sharp points and it strips out, that screw is really locked in. As I've explained before, I've tried every way I could think of to loosen one on the t-stat housing and have had to drill off a couple.

The thing is, when you have drilled down far enough through the head that the remaining ring of metal finally releases from the top of the shank, you do have quite clean threads right there at the top. Once you clamp a vice grip onto those threads and lock it down, that's over. Still with patience, you can finesse the threads with a 3 cornered file back to clean enough to get a nut on. Once you have one on, run it down a few threads then back up and down again, to clean the threads up more. Then get the second one on and as I've described earlier, you're just about done removing that stud.

Okay, suppose you do bugger up the threads and still can't get the stud to turn. The remaining threads make it hard to get a secure grip with your vice grip (with straight jaws and sharp teeth, not the curved). Take your nice sharp flat file and file off the threads on two opposite sides of the shank. You're not going into the core shank, just through the threads. Do one side first, then put the jaws of your vice grip on the shank to see the angle where the second jaw will contact the shank. Then file through the threads on that side. Now you should be able to get a very good grip on the shank and turn it out. Always use slow, steady force. As many have said, PB Blaster allowed to soak down the threads over night is a must.

There's also a screw head remover that's like a socket with angle teeth inside. Sears used to sell a set. That might work on the stud.

[mrwillie]

I've got the set from sears years ago, and never had a chance to use it. I need to get the "expanded" set that will fit the bolt, but it looks like this might be my chance to use it. I've been hitting the bolt w/ pb blaster and liquid wrench for the last few days. I've also got a pencil torch that I will start using while at work during breaks.

I was at pep boys today and they have a sale on the long torx set as well( $9.95, I think )

@xHeart -- Looks like my next items are ball joints, tires and the CTS( coolant temp sensor).

@JimBee -- thanks again for the info

[JimBee]

I should have mentioned about the Sears screw head removers it didn't work on the small screws I was trying to remove on a Nissan fuel pump mount. They were corroded like the Volvo t-stat. I ended up drilling those off, too. Then the shanks came right out.

Be careful with the pencil torch. I'd keep it trained on the screw shank not on the t-stat body. Those little flame throwers can get pretty hot. The other thing you might try is if you have an accomplice, after heating the shank, get your vice grip on it and have someone tap the top of the shank with a small hammer as you try to unscrew it.

[mrwillie]

Good to know about the pencil torch. I've had decent luck in the past heating a bolt or the area around the bolt and spraying it w/ kroil or PB blaster while its still hot. Sometimes, you can get enough to be wicked into the area around the bolt to help loosen the bond. I'm gonna try to get on the car when I get home. Hopefully, I won't get side-tracked again.

Thanks again!!

[mrwillie]

Update...........

I drilled out the bolt this weekend and was able to remove the shank w/ a pointed pair of grip pliers. The shank came out very easy, having been soaked in everything from liquid wrench to pb blaster for the last week or so. I didn't drill it completely vertically, so I drilled into the outer edge of the housing cover but it doesn't leak. I also changed out my thermostat, ECT, ignition rotor( plugs and cap had been changed previously -- orig wires go next ) and did an oil change. I ran out of time, but will do the fuel filter, first transmission drain and fill, and p/s fluid flush. Thanks again for everyone's help!!!