Hey guys, been working on my car for the past week installing long tubes and finally got that done when I snapped the serpentine tensioner bolt clean off and rounded off a torx bolt. Any Idea on where to proceed from here.

 

Double-whammy there. You could:

-Soak the bolt head with PB Blaster, lightly tap in the largest hex bit that fits and carefully turn.
-Use a special extractor bit.

 

There is no bolt there, that's just the operating nut, no need to further mess with it. The pulley is only held on to the "auto tension" mechanism by that tamper proof torx bit in the middle. Get the correct tamper proof torx bit (which I don't know off the top of my head), remove the pulley, remove the auto tention mechanism via the one torx bolt you can see and the one that's behind the pulley that you will be able to get to once its off. Replace auto tensioner.

Or, if you're in a tight spot you could ignore it and use a pry bar to try to find an angle lift it and get the belt on. I always find putting the belt on is easiest at the alternator, fit it every where else and pull down on the belt to loop around the alt while some one lifts the tentioner.

 

Ouch. Been there, done that also.

What worked for me was finding the correct size Torx bit and tapping it into the bolt head using a small hammer. I then put a wrench on the Torx bit while again tapping with the small hammer. It broke loose and out it came. There is a second Torx bolt on the bottom most likely under the pulley. Like drothgeb said, get the security Torx bit and remove the pulley. That should give you a bit more room to work.

Until I removed the stripped bolt, I was afraid I was going to have to pull the radiator to get enough room for a right-angle drill and extractor bit...

 

Oops I missed that you had rounded that torx. Damn.

 

Righty tighty, lefty loosey. That "bolt" you forcefully sheared off isn't a bolt.
Please don't work on your own car anymore.

 

weld a descent size nut onto the broken stub with a mig welder ,,,, simple ,,,, maybe I misunderstand the situation

 

Welding a large nut to the remaining stub is a good plan. A big part of the effort in doing that is the welding heat breaking loose the steel bolt shaft from the alloy material. This will reduce the chance of the treads being torn out as the bolt shaft is turned. Using a Tig welder will allow for even more heat and control of it while the nut is welded. With the right amount of heat the bolt shaft will unscrew with relative ease. Good luck.

 

Ill take everything into consideration, thank you guys for replying with the quick tips!