I;ve got a 95 850 N/A with 235K. Other than overheating (which I am not), is there a way to diagnose whether or not the thermostat is broken? Months ago my mechanic told me it needed to be replaced. I purchased the part on FCP, bought the necessary tools and looked up the "how-to's..." and the job looks simple enough. However, I did have the unfortunate torx bolt stripping happen to me (even though I lubricated with PB for a week prior to turning the bolts.)

So here's the question: I've driven to Wisconsin and back, and Michigan and back...both over 400 mile round trips, and both on hot days. I have not had any issues with overheating, and my temperature gauge in the car reads steady in the middle. For my next trick, I need to figure out how to remove the stripped bolt, get the other one out without stripping it, and do the job. However, if the thermostat is not broken, I'd rather just leave it be for now and work on the other wagon (a 94 850 with troubles of its own!)

I don't think there are any trouble codes for a broken thermostat (are there?) so short of the "place the thermostat in water and see if it opens at X degrees"...is there anyway to figure out whether or not I'm wasting my time here without actually opening up the housing?

Thanks!

 

i think most thermostats have a fail safe open
if your temp gauge is in the middle it is prob ok
you can use a temp gun on the housing, or feel it
you should be able to touch it, but not for long
as for the stripped screw can you get vise grips on it
and heat the housing where the screw goes through first

 

i always grease the bolts, and any rubber seals or o rings too !

 

That's what I was wondering...I've felt the housing and the hose to the radiator and they are both hot to the touch after running for awhile, so I am assuming that the coolant is running through (which makes me think it's working correctly?).

I'm just not sure how the mechanic originally diagnosed a faulty thermo?