what temp stat did you buy?
have you pressure tested ur rad cap?
do you still have that restrictor? if so remove it
Do you have a way of reclaiming refrigerant?
When the temp was at +100C was it boiling?

I myself wouldnt buy the evap, your issue is heating
If anything just the HC
hope you got someone to massage your neck after working upside down all day lol

 

Good Morning, in response to Hemi4spd, the new Thermostat is a 195 degree, this is the recommended one that I purchased at our local Dodge Dealer. I have not pressure tested the Rad Cap. I have since removed the restrictor and when I noticed when I changed the water pump that the size of the orvices for the heater hoses are only 1/2". I am going to have the refrigerant reclaimed at the shop. The temp on the gauge was reading slightly over 100, this is when I stopped driving and I removed the the cardboard, I did not see or hear of any boiling, say boiling over to the coolant overflow container. And lastly, the reason for replacing the Evap, is simply to do this while I have the whole dash and Hvac removed, it is for precaution only. I know that this will be a very challenging job, but I hope that it will be woth it in the long run. Colin

 

Well I changed the Heater Core and the A/C Evap today, 5 hours, Sat. Jan. 22, 2011 and guess what, still POOR HEAT. The A/C evap had a wet spot on it so it needed to be changed. I cut the old heater core at the bottom so I could see if there was a blockage, there was some corrosion there that may have caused some slight flow restriction but there were no complete blockages. What's next I don't know and today our temp dropped below minus 30 Celsius.

 

So the new TStat seemed to fix it for awhile.. but now when the temperature gets really cold (-25C again the last couple days), the exact same thing is happening again. Faulty thermostat out of the box?

I'm thinking it's probably something else..

Should also mention, when the temperatures are warmer (IE - above 0C), the van warms up normally. But when it's really cold, it seems to be taking a good 45 minutes to warm up.. and even then, it's not as warm as it should be on the gauge.

 

Birchy: I have given up on this Dodge Ram, it runs cool until it has to work harder, ie pulling a trailer, travelling on the highway with a cardboard in front of the Rad or 4x4ing on the lake in the deep snow. Otherwise it is warm air at best. Colin

 

From what i am reading. Is all the member live where it is really cold? The reason i ask, You all seem to have the same thing in common. I like colins ideal. When warming up the vans, block the air flow to the radiator and turn the heater on. See if that makes a differents. And post your finding.

 

Normally I would be okay trying this master tech, but it seems to me something else is wrong. The reason I say this is because I have a couple friends that have the same generation of Grand Caravan and they're not having any issues in this cold weather. I've asked them.

Lately the temperatures have been warming up a bit and the van seems to be warming up to the normal operating temperature. However, for the last while I've been noticing a smell like burnt coolant. Just now after getting home from work, I decided to have a look at the system again, and when I squeezed the upper rad hose I noticed it was rock hard, and still cool. I slowly tried taking off the rad cap and the coolant that sprayed out is still cold.

It seems to me like the thermostat is still stuck closed (even though it's new) and the coolant isn't flowing through the whole system properly. Does this make sense?

I think I'm going to replace the thermostat again since they're so cheap. I might even be able to get another one on warranty since it's only been a couple months since I bought this one.

 

I would say you maybe right,but a t-stat stuck close would cause an overheating problem. It maybe stuck open all the time.

 

Stuck open! Interesting.. now that you mention that, when I squeeze the upper rad hose when the engine is cold, I can hear the thermostat clicking when the coolant goes back and forth. Maybe it's opening and closing way too easily? Then when it's running, it would be stuck open..

 

Got a warranty replacement on the thermostat and replaced it again tonight. Problem is resolved, again.. for now. Same thing happened last time, so we'll see.