Hi guys, need some help with my van. 02 Grand, 3.3, 123000 miles, getting no heat, and the van is threatening to overheat, but doesnt unless i drive it hard. Thermostat has been replaced, and i checked the heater core hoses after i just flushed them(today), to find no blockage. I've squeezed the radiator hoses, and its not a blockage in the motor, radiator. Someone has suggested the blend doors, but when i switch from vent to defrost, a certain set works fine, just blows cold air, so i'm not so sure about that.

It's snowing quite nicely outside, so any help would be helpful.

Thanks for any and all helpI have read, and agree to abide by the DodgeForum.com rules.

 

feel yalls heter core hoses and see if they are hot if they aint then yall got an air lock in the system or water pump going bad

 

You could have air built up in the system...when you heat it up open the radiator cap just a little bit and see if air comes out.

 

I had a similar problem on another car years ago. One thing you can try it to open the radiator cap as well as the overflow container where you normally fill it with antifreeze. Then jack up the back of the car to get gravity to help with the air bubble. After you have it filled run the engine. You should see the fluid moving through the system when you look at the fluid in the radiator with the open cap. This should push the air bubble through. If you cannot see the fluid moving through the system you probably have a bad water pump. They do go bad at 90,000 on the Caravan.

 

As the engine warms up, remove the radiator cap (be sure there is no pressure) hold engine rpm around 2000-2500 and watch coolant level,if it drops, top off radiator and then put cap on tight, then let off throttle. Also, ever think that the water pump has failed. I've seen a lot of impellers fail or freewheel on the shaft. Additionally, feeling the heater hoses is a valid check for tempurature, also if the upper radiator hose is getting warm as the heater hoses are warming up, then the thermostat is leaking/stuck open. The close to overheating would not be related to the heater box doors.

 

I had a similar problem on my '96 3.3 liter after I changed the thermostat, I stated her up, drove off and suddenly the temp needle went to the top and I still had no heat, I pulled over, took radiator cap off (carefully) and then burped the upper hose a couple of times, started her up and let her idle (no problem) then I put cap back on and drove off (so far (6,000 miles) and no issues, and yes, I now have heat. So I assume air trapped in the system.

 

Just picked up a 2002 Caravan at auction this week and I'm having a similar problem (yay Canadian winter!). Never had heater issues with any car before so this is a useful thread.

My slight variation on this is that we do get heat right after acceleration. When at idle or cruising at highway speed it blows cool. But when you come to a stop sign or traffic light, it will blow hot for about 10-15 seconds after accelerating back up to speed.

The engine temperature gauge rises to dead centre and stays there.

The car had been sitting in a frozen auction lot for 2-3 months so I will gradually be changing/flushing the oil, tranny, coolant system.

Edit: okay, one of those "duh!" moments - I popped the rad cap off and no coolant to be seen! I had about 1 qt of 50/50 left over from a previous job and added it - almost full but will have to go out and get some more. Now the heat works. Desperately needs an oil change too - black and below the "MIN". I'm impressed because I already drove her 100km!