My thermostat is stuck open - engine is running cool. Does this need to be fixed immediately or can this go for a few hundred more miles before being fixed? Will it damage the engine? Thanks.

 

If I remember right you should be ok. The problem comes when tstat closes and won't open . An engine will run fine w/o a tstat. Having said that see what everyone else has to say

 

I'd go and change it immediately- because if it gets unstuck and then stuck again in the "closed" position you'll overheat. That could do some damage. Running too cold per se isn't damaging, but increases wear and can lead to premature oil breakdown in conjunction with biodiesel. (More blowby at cold engine)

HTH

AlpineRAM

 

99% of the time the reason it's stuck open is because the internal rubber sealing ring came off and is stuck in the stat. The way I fix these is to remove the stat and trash the ring. It doesn't seem to make any difference with or without it.

 

If you need to I would drive it but watch the temperature closely not to miss if it overheats. If it starts to, don't let it overheat, pull over. And fix it soon.
-P

 

If it does stick shut on you and you are in a jam! Just pull over and pull out the Thermostat and go without. I would do this only if you get in a jam beats overheating a truck!!

 

NEVER remove the thermostat and operate the engine, there is a integral passage in the head and block that is the bypass for the thermostat, if the thermostat is removed , you will be get any circulation of coolant to the radiator and the water pump will draw the coolant from the bypass passage and the engine will overheat.

 

Thats why I said only if he is in a jam. If it sticks shut he is going to overheat anyway! I would just go ahead and change it but if it sticks shut and he only needs to go a few more miles to get home then I would pull it and head home.

I would just go ahead and change it, makes it easier in the long run. Plus you don't have to worry about getting stuck with a hot truck!!