Pontiac Repair: Thermostat // Thermostat Housing, pontiac sunfire, chevy dealer

Question
I have a 1998 Pontiac Sunfire 2.2 ltr. I recently was attempting to replace my thermostat when i noticed that the new one was not correct. ( not the right size_ So i put the old one back in and tightened  everything down  ( i think i might have over torqued the bottom bolt) because now there is a leak  coming from the housing. I have not managed to find a new housing at any auto-parts store. SO my question is how might i go about fixing this leak?  ( did i maybe just re-install the thermostat wrong) If i did crack the housing, why can't i seem to find a new one to replace it?

Answer
Hi Garrett:

You may have put the thermostat in crooked and or the seal that is on the thermostat is worn out from being compressed already and taking it out and not getting it back in the same place it's leaking. Goto the dealer and get the correct part. any Pontiac or Chevy dealer should have the correct one that engine was only used in those 2 brands. The new thermostat will come with the seal on it already. Aftermarket ones don't fit right and you need to buy the seal separately. If you did over tighten the bolts thay may be stripped and if that is the case your going to have issues the holes will ne to be retapped if there is enough material left in the holes. Good luck :)