I have a 2002 Dodge Grand Caravan 3.8L. The temp gauge shows cold and never indicates the engine is heating up. The heater blows cold air. Then if it sites at idle the gauge shows normal medium heat and the heater starts workings. When I continue driving the heat blows cold and the gauge indicates a cold engine again. What is the problem? I'd like to have heat while driving.
Thanks for any advice.

 

is there coolant in the system?
if yes then you need a thermostat
cost about 10-15 bucks

youll be able to get warm again

 

I'll 2nd what Hemi said. Sounds like a thermostat. Easy fix if that's what it is.

 

Yes the coolant level is at the top. I purchased a thermostat yesterday. Will attempt to replace. First have to find the drain plug on the radiator. Thanks for the help.

 

Drain plug is located on the lower driver's side of rad. There will still be quite a bit of coolant in the block so you will most likely spill some. Pay attention to how the old one comes out. Install the new one the same way. Best of luck with it! Should be easy.
Common sense tip - Do it when the engine is cold/cool to avoid getting burned.

 

I have the same problem, but when we are driving we lose heat. We have checked the radiator and added fluid. That worked, but now its back to blowing cold air. No fluid is coming from the heater coil or water pump. Would we have to change out the thermostat?

 

Tia
sounds just like the symptoms of a bad thermostat,
have someone check the hoses running to the heater core(they should get hot) if they dont then its the stat, if they are hot then its likely in the blend door mechanism

 

We changed the thermostat, it worked fine lastnight. I got in the van this morning and it heated ok, then turned it off for bout 5mins and turned back on and no heat again. If the water pump is going bad would it permit heatting?

 

Replaced the thermostat yesterday. Heater is working great and the temp gauge is registering normal heat levels. Found the radiator drain but didn't have to much spillage out of the block. It was very easy to replace. Hardest part was getting the radiator hose off the thermostat housing. Thanks for all the help!!

 

TIA are you down on coolant again?