Q: The thermostat has been replaced in my car twice in six months because the Service Engine Light keeps coming on

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when my car first ran hot I had the thermostat replaced a few months afterwards my service engine light came on again and went to autozone and it said replace thermostat...so mechanic thought something was wrong with thermostat so he took it out and replaced it...now two months later my engine light is on again saying replace thermostrat again....its has to be something else wrong

My car has 139000 miles.
My car has an automatic transmission.

The thermostats on this engine have an electrical heater element intended to help the engine warm up faster. Many thermostat housings for this engine are plastic - from different suppliers. The plastic housings tend to leak around the heater wire plug, and corrode. Engine management "sees" the bad connection from corrosion to the thermostat heater as a failure, setting a problem code for ’replace the thermostat’.

Replace the thermostat with one with a metal housing, and the problem should go away. I would recommend having a thermostat replacement completed by a mobile, professional mechanic, such as one from YourMechanic, to diagnose this problem, get an accurate assessment of damage and cost estimate for repairs.

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