My heater blows out luke-warm heat and takes forever to warm up when trying to defrost the windows. Does this sound like a simple thermostat issue?

 

It could be the thermostat or a partially clogged heater core. What does the temperature gauge show? Is the engine fully warming up?

FYI-I deleted your other post, duplicate.

 

Thx for the dup delete. The temp gage seems to be reading normal. It takes about 20 mins of highway driving to finally get a little heat to produce.

 

If the engine is warming up, in it's usual time, and you're not getting much heat then I'd think your heater core is partially clogged. Feel both hoses, they should both be hot.

You can disconnect both hoses and flush out the core by itself to see if it helps.

A new thermostat (OEM is 195) isn't that expensive and is fairly easy to change. What engine do you have?

 

V6 3.9l

 

Is the heater core located by passenger firewall? What's the easiest way to flush?

 

It's on the firewall, drivers side.

Disconnect the two hose going to the core, which ever end you find easier. Hook your hose up to one side, leave the other unhooked, and let the water flow through it.

Try it both directions. Sometimes reversing the flow can help flush it out.

 

Thx for the great info! Should I try putting a thermostat on first or after I try flushing the core? What should I be looking for when I flush the core? sediment, rust, particles, etc. What things would cause the core to clog?

 

Since you say the engine is warming up try flushing the core first. If you're careful with the hoses you won't lose much antifreeze.

If you can direct the flow out of the core into a bucket look for "crap." I think it's the more generic term. It could be anything.

 

I need to do the same to my dakota, ive got 0 heat what so ever, the return hose for the heater stays cold while the intake hose gets warm like the rest of the engine, and my engine had pure water in it when i bought it off the PO

Im going to do that when i swap my head since ill need to remove the belt