New Bad Thermostat

[justchecking]

I installed a new thermostat about 2 months ago when I was working an overheating issue. I noticed over two months that the engine was running a little cooler every week. Finally, yesterday it was running about 180-185. So I picked up a new Motorcraft tstat (I forget what the other brand was, but it was supposed to be a 195) and put that in. Now the motor is back to 195. The other one looks ok. I might test it and the original (with 130000+ miles on it) in some hot water later. So new tstats can be bad!

 

[BrooklynBay]

Parts are mass produced on an assembly line, so it's possible to get a lemon (just like cars).

 

[mrboyle]

Seen this more than once. Hard part is trying to convince a customer that the t-stat they installed is bad even though its "new".