While replacing the upper radiator hose on my 351M Bronco engine, I decided to check the thermostat since I suspected that the one installed by the previous owner was of too low of a temp. I was correct; it was a 160 degree thermostat and the specs call for a 195 degree thermostat. Since it was Sunday, all the parts stores were closed except for AutoZone. Skeptically, I eyed the "Made in Mexico" thermostat for $4.99 and shrugged. "It's jsut a thermostat," I figured.

I installed it, started the engine, and it promptly warmed up. In fact, the temp gauge climbed past the first marker in the normal range, soemthing it has never done, Heat wasaa plentiful. I drove it and noticed the gauge dropped down to the first mark.

when I drove it the second time a few days later, I had driven nearly TWENTy MILES before the gauge moved between nothing and the first marker inthenormal range. The heater was but lukewarm.

Did I get a bad thermostat? Is AutoZone known for low quality import auto parts ('course I know that so many parts are made out of the country.)

I plan on going to my regular parts store tomorrow and getting a better made thermostat.

 

I did the same thing and went with a 195 degree one from AZ and have had ZERO problems so far. The only problem that I have with some AZ parts is the quality of their remanufactured parts even though I use them on mine.