my heater in my 98 dakota sport 4x4 5.2 V8 5 speed manual doesnt seem to put out very hot at all the radiator is full it has 197 degree brand new thermostat in it and the trucks temperature gage goes up but it just isnt very warm heat blowing out. I tried cardboard in my radiator and it helped a little but does anyone know is it just these trucks dont have great heaters or do i have a problem somewhere

 

Did you check your coolant level? Could be a problem if it's low. It happened to me.

 

well my radiator stays full but the reservor doesnt stay full if i add any to it does that matter?

 

couple of things:

1. reverse flush your heater core.
2. operate the heater on top or bottom vents only. when you place the dial on both top and bottom, it runs your ac. this in turn would make the engine work harder/produce a high operating temp., but for some reason seems to cool the air entering the cabin. see for yourself. have your hood open with your engine running. turn your temp. control guage to the hottest setting, place the air ducts setting to both upper and lower, then turn it on. you will hear your ac compressor kick on. you will also notice the signature puddle of water under your truck after a while.

 

virused your AC will turn on and off reguardless where the dial indicator is positioned ,it is made to cycle the AC thru out the year to keep the bearings lubed and the refridgerant circulating so it doesnt loose its punch so to speak .
mine was doing the same thing it would be warm when the fan setting is on 1 or 2 then blow cool air on 3 and cold on 4

i temporarily unhooked the AC compressor to see it this was my problem and now i have to turn the heat setting down because it is gettign good and warm now ,so it has ot be something in the dash panels or the controls that is allowing the AC to run all the time reguardless if you have full hot or whatever

 

this is the first time i have ever heard of this cycle. has anyone else ever heard of this? either way, the compressor will come on if the vent control is put to both upper and lower vents on at the same time no matter what temp setting you are using. it will also come on if you put your vent settings on defrost.

 

I was having the same problem with my truck also. I was getting warm air before now its extreamly hot. Now you said it had a 197 thermo? As far as i know stock is 180. But that really shouldnt mater. If you put the thermostat in yourself did you drain the coolant or did you just pull the thermostat housing off? It maters because if you just pulled the housing you would get air in your lines. Some people poke a small hole in the diapram to bleed air. What i would recomend is completly flushing your coolant system. See if that makes a difference. If that doesnt then check your thermostat again. And if its not that check your heater core.

 

well one problem with the air conditioner theory my truck doesnt have it what so ever and the new thermostat was put in when they pulled the engine out of my truck because i bent a rod and it had to be rebuilt so everthing should be fine with it so i might have to try the backflush thing

 

take loose the heater hose at the fire wall. Flush the core with a garden hose both ways. Mine is a 99 and it was doing the same thing. I put a meat thermometer in the dash to see what the vent temps were. The Dodge, with the blower on low, was 140F. My s10 is 175F. I flushed the core as discribed and now the Dodge is 175F. It worked well for me and was easy. It only took me about 10 minutes to get everything out, flush, and put everything away.