Runs cool

[Rs051802]

I have a 95 1500 with a fresh 4.3. 10k on new motor. I drive it approx 20 miles a day in 4 -- 5 mile long trips. The engine never gets warm, or even begins to. I drove the truck 10 miles in 1 drive today and the gauge did not move, and I could touch the block and heads with bare hands, they were luke warm. I have a failsafe thermostat, could it be stuck open? Would that be a bad thing? I recently replaced the heater core as well, and radiator is full. Should I get a regular thermostat? Or is it something else? Thanks for the help.

[broughy84]

Fail safe thermostats are nice, I like them because when they do fail they "stick" open. I would say that you need to replace the thermostat and see what it does. Whether you use the same kind or a different brand you need to change it. These engines are designed to operate at or around 180 - 210. They need to be regulated so the computer can no when and how often to fire the injectors to get the right fuel/air mix.

[jveik]

are you using a radiator for that particular engine? My buddy replaced his radiator for his 454 with a better one and it ran considerably cooler as well.

[abaird]

Originally Posted by jveik

are you using a radiator for that particular engine? My buddy replaced his radiator for his 454 with a better one and it ran considerably cooler as well.

Keep in mind, like broughy said engines are designed to run hot. The hotter they run the more power they produce, to some extent of course. I never understand why people put low temp thermostats in. If they come factory running 210, LEAVE IT ALONE!

[Rs051802]

I do not have a lack of power, the 4.3 runs like a 5.7 The radiator is the original, and the long block purchased had same serial numbers as the one i pulled. I will check the thermo, hopefully that will be the prob. It almost seems like the gauge is not working, but when you touch the block you realize it is working, the engine is still cold.

[jveik]

yeah i mean cooler in a bad way. wouldnt it be best to run to the point of just before pre-ignition? that seems like it would expand the mixture and hence the total compression as much as possible. Also, i hear that running a cold engine hard can be very bad for it since the oil hasnt thinned very well and is harder to pump around to various friction areas

[Rs051802]

Originally Posted by jveik

Also, i hear that running a cold engine hard can be very bad for it since the oil hasnt thinned very well and is harder to pump around to various friction areas

Well lucky for me this has not been going on for long.


I put the new thermostat in tonight, sure enough the fail safe was open, and now the engine runs great, and warms up nicely to about 180. I went with another failsafe. I would much rather notice my engine cool than have it overheat and crack a head. Thanks alot for the help!