I have a weird heating problem. When I turn my heat on it blows hot for about 2 seconds and then it hours warm and then it goes cold. Both heater hoses are hot along with the top radiator hose. The bottom one is cold. I've replaced the thermostat and it hasn't helped.

 

Sounds like a vacuum leak or a bad blend door in the dash.

 

Or low on coolant.

 

OP, have you tried bleeding the system with the truck parked up a hill when cold and have the radiator cap off. Let it run a few mins with the heat on and this burps the system. It's very possible it could be air in the system as hey you said.

 

I have not. Every time I've let it run with the cap off it's always just started running out. Should I let some come out if the coolant level starts to rise?

 

yes. Let it bubble and burp out all of the air.

 

So when it starts to go back down just pour in more coolant until full? Sorry it is the first time having to do it this way.

 

Yup. Keep adding until it stops bubbling from the air and its full. And if you do over fill the rad, no biggie. Then it will just go over to the over flow tank. whoda guessed I have to burp my system this weekend when its not so *** biting cold, pardon my french, so I can actually bare to be outside. Dont want to thread jack but seeing as bot OP and I are losing coolant, I have no leaks but dot know about OP, how else can a vehicle lose coolant?

 

They either eat it through one of the cracks in the heads or it's seeping into the clogged heater core that's in every ram.

 

I had mystery coolant loss for quite a while before it finally started leaking enough to leave a puddle on the driveway. Mine was from the freeze plug behind the drivers side motor mount.

The little bypass hose from the w/p to the intake is another good spot. Coolant pools on top of the timing cover, and basically boils off, never leaving a puddle, and you can't see it there either.