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My wife was driving back from Denver when she says the service engine light came on. Said temp was fine as well no other lights so had to swing by advanced on the way home. Told her it was a thermostat code but didn;t give her a print out so not sure which. I was planning on doing some cooling system maint but not this soon, so ill prob just replace the t-stat for now.

When the t-stat goes bad does it a fail safe open? Most likely the original one and need to drive to denver again tomorrow.

How buffered is the warning system on these cars? Or is there a warning chime or light if its getting hot?

Are there any aftermarket t-stats i should stay away from?

thanks
 

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Replace the t-stat. They can fail either stuck open or closed. Also replace the expansion tank. And if its an automatic the trans fluid heat exchanger t-stat may break upon removing the exp tank. I usually replace the bleeder screw on the upper rad hose, as the tend to break if they've never been replaced.

Fyi...when the engine its overheating the red warning light in the temp gauge will illuminate.
 

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When you replace your cooling system parts, flush a couple gallons of distilled water through the system, drain it and fill with new coolant and distilled water. There seems to be a lot of crap that builds up in the system.

Once you get a full gallon of coolant added, fill to the brim with distilled water. Open the bleeder screw and continue to add water until it drains out of the bleeder. Close bleeder. Start car, turn on heat full blast, full heat, and feed more water in until it tries to overflow. Shut off car. Let engine cool. Check coolant level and add more water as indicated on the turkey timer that pops out of the expansion tank. ;) Repeat checking coolant when engine is cold the next couple of times you drive the car. This is the easiest way to make sure you have no air bubbles in the system and the coolant level remains correct.
 
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