A month ago the t'stat stuck and car overheated and dumped antifreeze from tank. I replaced the T'stat & belts and was driving home Tuesday and it started bucking and gage was hot but no warning lights if any, so I stopped the car and it was bubbling in the tank and blowing some out the overflow.. Had it towed and radiator shop said block was not holding pressure. Would a leaking head gasket cause it to overheat if still had coolant, or did a faulty t'stat (just replaced) cause it to overheat and blow the head gasket. It did start bucking just before I cut it off and would not accelerate. I hope the shop did not blow the head gasket when they test drove it to see what was wrong.

 

Yes it's possible, some people only overheated once!

 

I'm just wondering if something was wrong with the previous T'stat fix to cause the exhaust gasket to blow or could the gasket blow w/o the engine overheating with 92,000 miles but this car has been oil changes only, except for the bad window regulator, now that was a weird one.

 

Follow the troubleshooting analysis steps in the FSM

http://www.nicoclub.com/service-manu...5_G35_Sedan/co

See page CO-6

Telcoman

 

There's only two reasons I've ever seen a blown head gasket:

1. Very high boost, like +20# without doing deck work to the block.
2. Overheating, and it usually warps the head enough on the first overheat to blow the gasket but sometimes it can take a while (weeks) for the gasket to finally fail.