Thanks for your suggestions on a previous posting!!

Do you think I should replace the thermostat with a lower-temp one, or just leave the stock one alone?

Thanks again...I apologize, I do not have that much knowledge to share with you guys, I just keep loving my little truck more every day!

 

Unless you are planning on doing substantial track racing you are better off with the stock thermostat for several reasons.

a) a hotter engine is a more efficient engine. If you could toss the radiator and cooling system entirely, you'd get better mileage because you would not be tossing off all that heat. Of course, right now, you engine would burn up.

b) cooler temperatures in the cylinder head and combustion chamber promote incomplete combustion and carbon build up in the cylinder, which will lead to hot spots and predetonation.

c) if you use a very much cooler thermostat, you never really get to the correct operating temp on cold days. Your engine clearances were designed with a specific operating temperature in mind.

d) today's engine control management computers use engine temperature to regulate timing and fuel flow. You can upset proper operation with the incorrect thermostat.

 

When should the thermostat be replaced? I haven't noticed anything about it yet in the service manual...

 

when it stops working. you dont really need to replace it as regular maintenance, they'll last a while. usually lower temp thermostats arent recommended because since their temperature is different, they sometimes let the coolant flow a little TOO fast and the coolant goes by the radiator so fast it doesnt have time to cool. this is the case in sports cars, im guessing the same rule applies to trucks...