I have a '98 Ram with a 318 engine. After the engine is fully warmed up, the gauge says around 180 to 190. Whenever I stop the vehicle and the motor is idling less than 1200 rpm’s…no heat. At highway speed I don’t get a lot of heat. It is adequate but it just seems like I should be getting more heat than I do. Please advise. I can be reached directly at donparadowski@yahoo.com

Thanks.

 

Low coolant level.

 

Partly closed heater core? Drain coolant fill with water and run a good engine flush for about an hr @ 1500 to 2000 rpm. Flush with water and fill with 50/50 (water and coolant) with one of the heater hoses off. so most of the air in the cooling system has some where to go. Once full Tighten everything up and let idle for about ten min. Then go for a test drive. Sometimes running the water hose (back flush) through the heater hose well help loosen some of that sediment in the heater core. Of course doing this if there are no signs of leaks and cooling system was full before starting all this.

 

justfrfun: Thanks but that was the second thing I checked right after the thermostat for proper function. I wonder about the possibility of a vacuum leak which I have not tested yet.

 

I was about to say vac leak that is not fully opening the valves to pas all of the air over your heater core.

I used to have a problem with my 1996 where there would be hardly any heat until about 5 miles of driving. i think that it was condensation in the vac lines that was freezing, when it unfroze, the vac lines worked.

Those things get brittle and crack. Looks good to the naked eye, but upon further inspection, they are actually not good.

 

core core core core. Higher RPM's push a bit more hot coolant through the system, so it's warmer, but not has good as it should be. If your sitting, in neutral and rev up and your heat increases look at da core being partially clogged.

 

check the hoses coming out of the fire wall one is in the other is out of heater core dont rev it up let it get to operating temp then feel both hoses at fire wall if one is hotter than the other its the heater core thats a easier way to check that than draning the system if they are the same check the flaper under the passenger side of the dash make sure its working properly those are two easy wasys to narrow it to vacum and cost nothing to troubleshoot.

 

I cannot find a vac leak but experience tells me that is the source of the problem. Whenever I pour on the power and hold it there, the heat cuts in (even when switched off) and immediately cuts out when I let up on the throttle.

 

i say replace t stat and buy a new core and do a coolant flush do stuff the right way dont be pouring flush crap and hoping for a fix do sh*t right

 

if it was a vac leak wouldnt u be getting heat out ur defrost ? vacum leaks is bs it wouldnt just be a heat realted problem it would have a issue with the whole cooling and heating system! amatures