I have had this truck about 3 months and I just tried the heater this week and it won't blow hot at all it is just almost warm. I checked the radiator and it is full. I will probably replace the thermostat but was wondering if anyone has had problems like this. I don't like the switch for the blower, I almost wonder if it malfunctions if the ac could be on. It is a 1998 with a 5.2 318 motor.

Thanks

 

This morning I had the heat on as well.

I noticed it didn't get "HOT" until I was well on the highway and already at operating temperature for 15 minutes or so. You would think it would at least be hot once you hit peak temp...

 

Well I thought about it some more this morning and my temp gauge reads about 190 to 200 when it it warmed up so I would think the thermostat is working. I have a 25 mile drive to work so I know it should have been blowing heat.

rhutson

 

most likely cause is an air bubble in your cooling system preventing the heater core from getting water to it. that or someone bypassed it after their AC condensor leaked water on the passenger floor

 

try flushing your heater core.

 

My 98 had the same problem, I replaced the thermostat and now its a lot warmer then it was.

 

I know it is hot cause when I turn the fan all the way down I can feel major heat around my feet but when I turn the fan on it is barely warm, I'm going to look in to the switch, I believe the ac is on all the time.

rhutson

 

i have the same problem with my '99 318 setting 1 or 2 some what warm but if set on 3 or 4 cold air nothing warm at all so i will keep an eye on this for a possible answer

 

^^ I concur. (Remember, when you flush your heater core, the water needs to go the opposite direction as normal ).
Also, flush the block and radiator is probably a good idea. And replace all the coolant if its been a while (typically over 30-40K miles) or if it looks bad.