So my heat only blows warm air i have replaced the thermostat, water pump and belt. i dont know where to begin troubleshooting this. Anybody ever experienced this what was your fix? Is there a way to test or troubleshoot the system? Any advice would help can it be the heater core?

 

Does it still have the heater control valve in the heater hoses? If so, it might be sticking. Feel the hoses and see if the core is getting plugged and if that is the case you can flush the core.

 

Its a 98 im not shure but i do know you cannot find that part in the autozone computer. And flushing the heater core how is thst done? Does the coolant need to be drained? Is there anything to use other than water when flushing?

 

It would be less of a mess if it was drained a little. Pull both hoses off, be careful pulling these off or you might crack the core. I run hoses to it and out of the engine compartment to keep the mess down and use the garden hose from one hose to the other until it runs free. If you have a lot of pressure from the garden hose, don't flush with the trigger wide open, it may split the core with too much pressure.

 

Remove both heater hoses at the motor. Stick a garden on one hose and flush.

 

So does a 98 have a heater control valve?

 

And would flushing the core help with a slight overheating problem? It slowly overheats sometimes when ran with ac or 4x4 engaged

 

'97 up do not have a heater control valve. Flushing the heater core will do nothing for a overheat condition. Make sure the efan comes on with a/c. May need a new fan clutch and radiator.

 

What size tires, gears,and type of trans? Could be the whole cooling system needs to be flushed, wouldn't hurt to spry the rad fins out from the motor side.

 

Ive got 31s with a 4 inch lift stock gears and trans im not shure what they are yet though

 

My electric fan is not working properly i have bought a new relay fuse done the hotwire from fuse to battery and still sometimes it doesnt kick on the fan is still good i think cause i ran 2 wires straight to it and it went on and ran ok so im at a loss cause if the fan works and the relay is new what else could it be?

 

But in that matter my efan wont cause my heat to go

 

That was just for the part of "slight overheating problem".
How is the airflow out of the vents? I would still consider flushig the whole system,if it hasn't been done yet with the thermostat and water pump change. Also when the heater is on the heater core lines at the fire wall feel hot?

 

I'm having the same exact same problem with my Jeep. I'm going to try and flush the heater core to see if that helps. Thanks!

As for the slight overheating - I get that too in stop/go traffic. I think my fan cluth is going though so I'm just figuring they are separate, unrelated issues. The overheating isn't that bad, though.. a half-notch to the right of 210. It usually sits one notch below 210.