Stuck Thermostat?
 

I put a new stant 180 thermostat in the truck. Was letting it run for about 5-6 mins and the temp guage was dead center. I check the top radiator hose and it wasnt tight. Bottom hose was the same. I let it run for another 5-6 mins. No change. Is this a stuck thermostat?

Re: Stuck Thermostat?
 

sounds like to running right to me if your guage working right

Re: Stuck Thermostat?
 

I pulled the thermostat housing off to replace the thermostat. There was a ton of coolant in there. I replaced the thermostat and now it is raining so I had to stop. Also I forgot to add that I just installed a intake manifold on it since my last one cracked. Also could I need to "burp" the cooling system? I have heard of this but have not had to do it.

Thanks

Re: Stuck Thermostat?
 

Something else to add not sure if it matters but the heater blows out hot air.

Re: Stuck Thermostat?
 

Just my 2 cents. I have done them where after replacing the thermostat and filling with coolant i start the truck with the rad cap off, periodically feeling the top hose to see when it gets warm, and it almost always gets alot of burps out the top of the rad, installing the cap when it starts to boil over. Please do not take offense but is there the possibility that you may have installed the thermostat upside down? That would cause this same effect too. I did this once so I can say it first hand.

Re: Stuck Thermostat?
 

I always drill a small (say 1/8") hole in the rim of the thermostat, away from the sealing area of course. Then install it with that hole toward the front of the engine. This puts the hole in the highest place. This little hole will allow any air that could be trapped below it to bleed to the upper hose and back to the radiator. It is not significant as far as affecting overall flow/cooling, but it will stop the air pocket problem. Plus you don't have to wait for the engine to release this trapped air, and you can be sure that it is full.

The problem with trapped air is that the coolant doesn't touch the thermostat and therefore it doesn't open or it does so very late.

Re: Stuck Thermostat?
 

Tx Firefighter trick....

Open the thermostat with your fingers and wedge two aspirins in it to hold it open. Now install and fill with coolant. The aspirins hold the thermostat open and the air will readily burp out of the system till full. Once water starts circulating, the aspirins will disolve and be forgotten.

Re: Stuck Thermostat?
 

Good tip, gonna have to remember that one.

Re: Stuck Thermostat?
 

I have heard of that method........but it is not "perminent". If you would need to drain and refill the system you would need to open the thermostat housing again. The hole lasts as long as the thermostat.

Re: Stuck Thermostat?
 

I always do the hole thing...

Re: Stuck Thermostat?
 

Don't get me wrong, I've drilled the bleed hole in plenty of mine, but in a shop where time counts, the aspirins are much faster than getting a drill and bit out.

SECOND TX FIREFIGHTER TIP: Don't try to hold the thermostat in your hand while drilling the hole. When that bit catches, the thermostat will twist, and those edges are razor sharp. Been there.