Engine Cooling problem
1999 Chevy S-10 4 cyl Two Wheel Drive Automatic 150000 miles
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How do I replace the thermostat on my 1999 S-10. The truck is not running. It broke down on the highway - blown headgaskets - again. I will use one of the sealant treatments after I fix the thermostat. It will not start, even with a jump.

Coolant could be mixing with fuel causing your problem-get it pressure tested-