yea just keep letting it run, it will bubble and bubble, until the T-stat opens, then wham, it will empty all of a sudden, it this does not fix your gauge jumping issue, then I would go get a new coolant temp sensor. As for the heater I don't know.

 

It could also be the connection to the temp sensor. A bit of advice just in case you run into this in the future, the sensor senses water temperature. That means that if the temp ever should climb steadily (overheating) then drop to cold, that means you have not cooled off, but lost all coolant instead. I know this is not your exact situation, but the little people made me say that to you just in case for the future.

 

yep very true, its a water/coolant temp sensor, not an air temp sensor

 

The truck is not new to me i have had it for about 1 and a half years. The heat has always worked until now. The tempature isn't increasing and then dropping down, it just increases and stays hot. I started it up today and it got really hot but the top hose didnt get hot or have any coolent circulating threw the top hose. The block didnt get hot eather. When I ran the truck without the rad. cap on it fluid came out with very little air bubbles comming out. I think the thermostat isnt opening so I think thats why fluid came out with little air bubbles comming out. I talked to a shop today and they said that i should burp the entire system but I don't know how to do that so if someone can give me a detailed description on how to do that i would greatly appreciate it. Thank you and I will keep everyone updated on what else happens.

 

Either low on coolant, bad thermostat, or wrong water pump.

To burp the cooling system, just run the engine with the cap off. If it is blowing out coolant with some enthusiasm, you may have bigger problems. If it just gurgles out, let it, then top it off when the level goes back down.

 

Ok so yesterday I put another thermostat in and it opend up and nothing got hot but the temp got really hot and when i turned the truck off the radiator and the hoses started steaming... This problem is so confusing!!!!!!

 

It got really hot when you turned off the radiator? I do not understand what you mean here, please re-phrase that.

 

Sounds like you have a few things going on here.
My truck has a coolant leak, i get the gurgling from the dash all the time when it gets low, do you get this sound from the dash?
If you are not getting this sound your heater core could be plugged and you may not be getting proper circulation.
My gauge never show's hot it goes to normal temp and stays in that area(195 to 200).
But the temps your getting maybe caused from poor circulation of coolant caused by plugged heater core.
I would check heater core and thermistat off the list before replaceing sensor.
Thoughts?

Dave

 

Heater core being plugged wouldn't cause overheating.

I would verify the part number on the water pump. They may have given you the wrong number, and it might be turning backwards.... (to what it should be....)

When I did my plenum, when first burping the cooling system, it was difficult to get the thermostat to open with the major air bubble in there..... gauge went pretty high before the stat finally opened...... and even then I had to let it cycle a couple more times before all the air got out. (and the gauge stabilized....)

Make sure the radiator is full, start the truck, and run it at 1500 RPM, see if you can't convince the thermostat to open fully, and get all the air out.

If you don't get any air, just coolant, and the engine STILL overheats..... You have another issue somewhere. Is the lower radiator hose kinked? Is it getting sucked shut? How much flow do you see at the rad cap??