Can a car thermostat fail occaionally?

Question

Its a 94 Sunbird with a unique thermostat (you can open the radiator cap and pull the t-stat out with your hand). The t-stat has opened normally but then this afternoon it didn't open (upper rad hose was cool, but the engine was running hot). I pulled it out, and everything was cool (infact, overly cool without the t-stat). So I drove it home, and tested the t-stat in the boiling water. It opened properly this time.

I've since replaced the t-stat, and it works fine (for now). But my question is what would cause it to fail the once?

Answer 1

usually from binding due to wear..........won,t happen every time.....but why chance it..........buy a new one.....get a good one..buy a name brand....such as Stant,or Ever cool..........don,t waste your money on a cheap/will fit.....thermostat.......many will give you problem,s from the start.........hope this help,s.....good luck!

Answer 2

i own a shop,and yes they will fail occasionally and work good sometimes,and this stumps a lot of mechanics on trying to find out why a car is running hot,when i get them in that are doing this i just replace them this way i don't have to worry about it,but ,about 3 weeks ago i bought 3 from advance auto parts in a row,and all 3 of them was bad,so even a new one isn't perfect,but yes they can work when the want to,good luck,i hope this help,s.

Answer 3

Just like every other part on a car, a thermostat can go bad. It can go bad because of part failure due to age,part failure due to the coolant never being changed. But as for it going out only one time, maybe it had gotten clogged, but by you taking it out( movement) it could have knocked whatever it was clogging it to be removed.

Answer 4

They normally don't fail once. They normally fail gradually as the spring weakens. Could it be that the stat was in backwards in the radiator?

Answer 5

"It worked fine and then, for no particular reason, it broke. So I fixed it and now it works. What do you think was wrong?"

Answer 6

yes