very low heat 2002 grand

hi all.My daughters 2002 jeep has a heating problem,when the heater is on low you can feel a little heat,,but when you turn the blower on high it just leaves completly,, what do i need to do to fix this??as it is getting very cold here now it is the v-8 engine not sure what one though,, also this jgc does not have climate control

It is a 4.7L engine.

You need to flush out the heater core.

The best way I have found to do this is, using a hot/cold water connection hose like one you would use for the water lines to connected to your clothes washer at home. and cut it in 2 pieces from about 8in from the end. Disconnect both heater hoses from the engine. and put one hose (washer) in each of the heater hoses. Connect a garden hose to one of the washer hose ends and turn the water on. Run the water through until the water comes out the other end clear. then disconnect the hoses and reverse them and flush it the other way, just keep doing this until the water is coming out clean and clear all the way through. Compressed air helps loosen up the stuff in the heater core to help flush it out, but is not necessary.

Joe

thanks alot! tried flushing it out,,and man did it make a diffrence ,,got great heat now! just hope the heater doors dont let go now l
l

Thanks for the info,,was a great help,,flushed the rad,, engine block,, flushed out the heater core replaced the Anti Freeze and guees what ?i got good heat! thanks! now if the heater doors dont go bad,she be in good shape lol