I've lived in southern CA. most my life now in AZ. and I have never known anyone to have a plugged up heater core.

I think its a back east thing I'm guessing the extreme cold kind of turns the coolant into gel after a time or you are using to high a mix. I even use just tap water and never had a problem coolant always looks like new every time I dump it and that's every 3 years.

$10 to $20

 

I just read about the cardboard in another thread but it said only cover half. Left half, right half, bottom half?? I'm originally from eastern Washington state so am used to cold and snow. But with this Dakota I bought after moving to Oklahoma, these below freezing temps is uncommon and I wasn't prepared to treat the truck any different than my old Explorer. Also, I've been running 50/50 antifreeze. It sounds like I should be running less water and more antifreeze.

 

This may help I'm not sure in cold weather but it helped in AZ. switch to a 180 temp thermostat I get heat faster now before it took forever to get heat out my vents.

Also check the thermostat housing gasket they tend to have too much material and it kind of blocks the heater flow just match it up to both sides and see what I mean.

 

Also, what's the best temp for a thermostat? I have a 160° in now. And to test oone, put it in a pan on the stove and the thermostat should open when the water boils?

Just saw the above post.
Thanks, 98dakaz!
Do you use gasket sealer??

 

OH NO remove that ASAP not good for a 2.5 it will run very cold I tried it and removed it the next week my Dakota ran so cold and that was in summer in AZ at 110 temps.

 

Okay, the 160° comes out tomorrow. I'll trim the gasket to match the housing. Felt gaskets okay? Gasket sealer too?

 

Plain gasket is ok no need for sealer unless it shows any leaks after install then you will need it.

Or just use it

 

a 160 stat should actually have your engine light on for engine too cold too long. 180 is the lowest you should run. That's also part of your lack of heat, although mine starts working well around 100 degrees.

What are your water temps right now? When covering radiator, it doesn't really matter which half you cover. Basically whatever you can cover and be able to tape the cardboard on. Just make sure the temps dont get too warm.

On the thermostat, gasket only should be plenty. As Dakaz stated, take the bolts hand tight plus 1/4 turn or so, and recheck after a heat cycle. There's probably a spec for it somewhere in inch-pounds and I wouldn't expect it to be much over 50.

If you flushed last year and you think it's clogged again, it makes me wonder if there's stop leak in the system coming loose and clogging up waterways.

 

I now have a new 180° thermostat and new housing unit. Now I remember what a pain it was removing the housing to install the thermostat last year. What is the easiest way to move the serpentine belt out of the way so that I can loosen the lower bolt?

 

Take it off.