Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Problem solved! It was the thermostat after all. I wasn't looking that way only because it was already replaced by the dealer in Florida before my daughter drove the car home. When I replaced the water pump (which was definitely shot) I did test the therm in water and it seemed to operating ok...But, just to totally eliminate it as a possibility, I finally caved on Sunday and bought a new one. I tested them side by side before making the switch--and thought MAYBE the new one was faster-reacting and MAYBE it opened a little more...but nothing crazy different.
Sure enough, when i put it in, temps were COMPLETELY different! Maybe the first one wasnt opening far enough for good flow--or maybe enough to close the bypass? I dont know, but I ve been driving it for 2 days and it is running perfectly...
It makes me wonder if the Florida shop actually replaced the thermostat they charged my daughter $140 to change.
After all, if that hadn't been done, I definitely would have gone straight for the thermostat--and saved myself lots of time and agravation...but then again, i did replace a failing water pump, I stopped a few leaks (seals/gaskets) and replaced the timing chain (and the ps pump), which all needed doing, while I was in there. So, i guess all is good!
Thanks again for all your help you guys. I move on to my next car repair with a little more knowhow!
That's the problem with aftermarket parts these days - it's a crap shoot. :lol: It's SO easy to install a problem and not know it until later when some new symptom pops up. I'm not defending the other shop, just saying that NEW means exactly nothing any more.
If you get the opportunity? I'd love to know your infrared temperature readings with the new thermostat, compared to that picture you posted earlier. This is the kind of info that can be really useful to myself and others.
Also, what brand of 'stat did you install? Any useful markings on the old one?