Originally Posted by ronwhite71
I just had to deal with this heater problem this morning. It takes a little patience but you need to bleed/burp the cooling system. I just replaced the T-stat waterpump and fan clutch and degasser bubble(the thing you put the coolant in) after all these repairs i filled the cooling system back up and the heater would not work. Squeeze the upper hose several times then take off the radiator cap and start the truck let it idle for several minutes for the T-stat to open and then put cap back on. The bleed screw on the engine is not much help exept for refilling the radiator. I did this and now the heater works fine you just have to get the air pocket out of the system. You will need to do this anytime you change your T-stat or change coolant. I bought my truck new and the only issues i have is with the cooling system.It wants to run a little past the halfway mark when at idle or in traffic now so i plan to put an electric fan on the front of the radiator to deal with this issue.My truck has 216,000 miles on it and still does well it did have a blown head gasket and i was able to repair with blue devil (it actually worked) that was about 15,000 miles ago.I am sure that happened when it did overheat and blew a radiator this engine has a horrible reputation for overheating/heater not working/head gaskets so dont let your truck overheat. You can try to flush the heater core but i would not start there just try to get the air out and you should be fine i have done this for 2 other friends with the 4.7 and it worked fine sometimes it takes longer than others but it has always worked. Do not forget to make sure your radiator cap is good. It is presurized system and is a very functional part of the cooling system and is cheap. Hope this helps
Dude, that's some very helpful pointers, thanks! One question though!! I thought a vehicle would over heat automatically if it had a blown head gasket? Don't scare me my friend, that's a Job!!!! And knowing me, I would just tear it down and replace it fully, It would get to me knowing I just put some gasket sealer....