hello

heating core in my 2002 Ram blow hot air only for few seconds while the engine is hot (half way on the gauge). When i turn off heating fan for a while and then turn it on - again blow the hot air just for few sec and then air is getting colder and colder (engine is still same - half way on the gauge). I did drain the system this summer. Is there a chance of airlock? What can be the problem / how to solve it

Thanx for help

 

That was my guess was an airlock in your heater core. Your gonna have to burb your cooling system. Take your rad cap off and leave truck running until at temp. (WARNING: DO NOT PULL CAP OFF AFTER TRUCK IS ALREADY AT TEMP!!! HOT COOLANT IS UNDER PRESSURE AND WILL SCALD AND BURN YOU!!!) Just wanted to make that clear for everyones safety lol.When your t-stat opens you'll see your coolant level drop and bubble and move thru the rad. Add some coolant and button her up. You may need a few beers I had to do this twice before on my old chevy and sometimes it takes a lil bit of time.

 

It took me awhile to get the air out of my 02 4.7 after a coolant change. Had to burp it like mentioned above then let run an extra 30 mins while cracking the bleed screw every few mins.

 

bleed screw? Where?

 

Sounds to me like your low on coolant. Top it off after you let it cool down. Its best to top it off when cold... Then turn it on and allow it to get to running temp... and allow it to cool down completely. This allows the coolant to expand and push the air out... when it cools it draws coolant only.

The reason its blowing cool air is because there is no hot water circulating through the heater core...

Let us know if its low or not... It sounds to me like its just low.

NICK

 

On my 4.7 there is a screw on top of a gooseneck that the upper rad hose is connected to that is on top of block/manifold.

 

I had heat issue with my 02 4.7 with heat on pass side only and flushed my heater core with hot hot water from laundry sink and cleared all the crap out. lots of heat after that

 

IDK if the 5.7's have bleed screws but i will have to look at that on mine. I dont have any heat issues but would be nice to know if it was there or not.

 

sorry for late answer guys but been out for weekend - with no heating in the car :/ my coolant level is ok, running with open cap was done - doesnt help. What i will do next i will connect garden hose to the system and try to blow clean water under mains pressure true whole system.
Does anyone know how to remove heating core in 1500 SLT 2002 4,7 ?

THNX

 

In my signature there are links you can click on to download your service manual to assist you in removing the core should you need to do so