Hi Guys!

I need some help with figuring out my cabin heat issues. The cabin heat inside my 2004 3.7 V6 Dakota is barely there. I can get luke warm heat in the cabin if I have the heater in the recirculation mode, if I set it to fresh air I don’t get any heat at all. Both in and out hoses to the heater core get very hot, the upper radiator hose gets hot as well but the lower radiator hose it very slight warm. I did replace the heater core because it was leaking, a brand new t-stat. What else can I do?

 

 

Agreed. Flush the heater core, but don't pull the hoses off where they connect at the firewall. The pipes going into the core are aluminum and deform very easily. Pull them off where they connected at the motor. Pour some water mixed with radiator flush into the core and let it sit for a while, then flush it out with a tapered hose nozzle up against the hose. Flush both directions, then blow into one hose to expel the tap water.

 

Flush the heater core, but beware of water pressure. The core is designed to withstand about 16 PSI, our local water pressure is 90 PSI. If you run the garden hose at full flow you can crack the heater core.