I have air trapped in the cooling system in the heater core area. I get the sound of running water. I do not overheat and I cannot find any leaks. I have tried elevating the front end and "bleeding" the system on several different occasions. It has not helped. Any suggestions?

 

let the truck warm up until the thermostat opens and then leave the heater running on full hot. I believe on the 22re some mechanics even insert plastic tubing down the radiator fill cap to get a bit more burp action. Vigorous full panic stop may be enough to remove the air pocket-obviously do not do this on the freeway....

If you don't see a noticeable drop in water level then I would suspect the thermostat is stuck open the entire time-meaning never fully closing up. Try running without a thermostat at all to see if symptoms change.

Test the thermostat with a pan of warming to boiling point water-you should be able to view the opening increase in size and then close up as you lift if out of the water- but if it is old at all just replace it. Even a brand new thermostat can be faulty however so testing it before you place it into the housing is not a bad idea either. Lastly could it simply be in backwards? It's happened....

 

??? I do not remember which way I put the thermostat in so it could be wrong. I recently replaced it again as the last one showed very irradiate temps showing very hot and then backing down to just below half on the gauge. This one shows very consistent temps staying at about 1/4 this time of year.