Driving to work today, I got about half way there (20min)..and lost my heat inside the truck, and my temp gauge went to max (check gauge lights came on).I fugured if I ran the heat full blast the engine would cool down, but that didn't work, it still blew cool air. After pulling over, I sat there for awhile, and then started it back up..but that didn't help. I got out to look under the hood to see if there was something obvious. All my hoses where warm, the heater hoses were warm but not as hot as the radiator hoses. I released the vlve on the radiator cap a couple of times to see what that would do, I heard the coolant going into the reservoir. I then decided to go back home..as I drove the gauges were normal and the heat was back on in the truck. When I got to work..I called my mechanic, asking him if it was the thermostat sticking. He said probably not since I had cool air in the truck. He thought it could either be an air pocket (low coolant) or a bad radiator cap.
Any suggestions
Thanks
Barry

 

it could be either of those but it also could be the thermostat. if the thermostat is stuck open it'll run in open loop and you wont get heat inside the truck.

 

are you sure you wernt loosing coolant? there could be a leak either the heater core/radiator maybe a hose or internal engine leaks

 

I did not smell any coolant or see any coolant, my reservoir was full. Plus if I was leaking, would it come and go as fast as it did????
My thinking was that the thermostat was stuck closed, but didn't think of it being stuck open. If it's stuck open, and running an open loop, would that make my air blow cool and the gauge to go up. I just don't understand the thermostat process.
Thanks
Barry

 

maybe just try changing the thermostat and flushing the coolant system... it couldnt hurt

 

if your waterpump was bad then your engine bay would be covered in coolant. if the thermostat stuck closed, thenit would overheatbut you would still get heat inside.so it's probly just an air pocket or your low on coolant.


I gotta change my waterpump this week. nobody can get one till thursday[:@] looks like I'll be driving my moms 07 4x4 hemi ram for the week

 

If removing the radiator cap caused the lights to go off, then the cap may not be venting like it should. Also a Thermostat could be causing those issues as well. Both are inexpensive and should be replaced. If that doesnt solve the problem, flush the cooling system and make sure all air bubbles are cleared.

 

when i replaced my intake manifold i had to flush the coolant system. i then refilled it and once i put everything together and started it... it overheated. i figured there was just an air pocket. so i waited until the motor cooled down and took off the radiator hose cap, i then slowly added more coolant until it was at the right level at the reservoir while it was still running. that way all the air gets out of it and the system is full. it never overheated again.

 

Drove the truck back home without problems. In the morning, opened the rad. cap and started truck. After it warmed up, the coolant level was right to the top. Then I checked the reservoir, and unlike it was yesterday (75% full) during my problems...it was about 25% full..Took about 20 oz of coolant to get back up. It must of sucked out the coolant from the reservoir for the radiator.
That seemed to be my problem ...low coolant/air bubble.
But, when it's overheating like that and the truck vents are blowing cool air...where is the air pocket??? In the radiator?? In the heater core??? And when it is like that and the temp gauge goes up..is it really overheating or is it a false reading??
It seems like when I let the pressure out the rad. cap a couple of times(that day)...it must of cleared the air out into the reservoir.
Barry