Blowing cold air intermittent - 02 GC Sport
 

Hello again,

My wife reported the other day that the van wasn't blowing warm air, even though temp.gauge showed vehicle was sufficiently warmed up. After playing with the sliding temp controls, and cycling the power I received warm air. The next morning, had a very cold drive into work (short drive) as the same issue repeated itself. Given that the problem is intermittent, what should I be checking ?

Thanks in advance,
Rhino

RE: Blowing cold air intermittent - 02 GC Sport
 

Did some more testing, and found that it's not blowing hot air until the vehicle is warmed up, and driving. Seemed to be related to pressure, as when the vehicle stopped at a set of lights, the air cooled down. Also noticed that the 're-circulation' button could be activated while heat was on.. I previously thought this was not possible.

As I was about to pack it in for the night, noticed fluid dripping.. here are some pictures. Are these heater related lines ?



[IMG]local://upfiles/48987/53CA04A29CA04E5ABFB7C2D54BA2C56B.jpg[/IMG]

I realize this is a 4 year old thread.. but it never hurts to try.

I'm having this exact same issue. Did you ever figure it out? 2003 GC, intermittently blowing cold air and hot air. Seems to blow cold air once you come to a stop, and start blowing hot air while we're driving.

Just started noticing this since it's been freakin cold here in Calgary, Alberta the last while. It's been hovering around -25C (+/- 5C) for the last 1.5 weeks.

Have you replaced the thermostat?? The t-stat maybe stuck open,

Not yet. Actually, I worded my post wrong - I just noticed the problem tonight actually. But was thinking the cold temperatures over the last 1.5 weeks may have contributed.. or made it more noticeable.

Did some reading in my Haynes manual and that's what I think is wrong - thermostat stuck open. Engine is up to temperature and when I grab the upper rad hose it's still cold. I tried opening the radiator cap and got a splash of coolant.. which was cold still (thankfully for my hand).

Any chance a bad thermostat would cause an intermittent CEL, but no codes? Cause that's been happening for the past few months as well.

It could, but so can a loose ground cable at the battery. I would still replace the t-stat.

Poor Heat
 

I am presently having all these symptoms, poor heat at an Idle, better when excellerating, my motor is the 5.2 in a 99 Ram 1500. I checked the coolant level, I installed a new thermostst from Chrysler, I checked the flow of coolant through the heater hose, by removing the return line at the water pump and bumping the starter, it has good flow. I checked the movement of the Blend door and the effects of all the different settings on the heat/AC controller, this all seems to be moving correctly. I tried the CLR in the Heater Core for 30 minutes, I tried circulating Prestone Super Flush through the heater Core itself the flow is Good. I then installed a flow restrictor in the return heater hose, the hose is a 5/8" diameter and I put a 1/2" restirctor in there. I put a full size cardboard in front of the rad with a 6" diameter hole in the center. Nothing seems to help, I do suspect the heater core although the flow is good, perhaps the flow is around the outside of the core and not in the center area of the core??? I also suspect that the engine does not heat up enough?? Is it possible that the Catalytic Converter is not function properly? Possibly the A/C is not functioning as it should?? I am determined to find out what is the problem. Colin

colin your symptoms sound like a bad water pump or plugged heater core.
after you changed stat are you positive you burped out all the air in the system?


with the cardboard on the rad you should see temp gague a little higher than usual, is this the case?

the lack of heat wont have anything to do with the CAT

Poor Heat
 

Colin
I can say that I ran the engine for sometime with the rad cap removed and I did not actually see any flow through the rad, I am not even certain that the thermostat opened.

I suggested that Cat as the culprit because I thought that one of it's purposes was to create backpressure and therefore heat with in itself to perform it's burning off process. This used to be the job of the Heat Rizer Valve in the older vehicles. What you have suggested, the water pump or the Heater Core are two definate possibilities, the water pump would not be to difficult to change, I may try that next. Thank You hemi4spd.

Poor Heat
 

I have since tried the truck on the highway, with the full cardboard, the engine temp was over 100 Celcius so I had to remove the cardboard, this still did not make as much heat as I thought it should. So I went a head and changed the Water Pump, the By-pass hose, the Lower Rad hose, the heater hoses and the Belt tensioner and pulley. All of this and the poor heat is still the same. So now I have ordered the Heater Core and the A/C Evap. and I am going to change both these cores at the same time, I hope this will makes Good Heat. Colin

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

Blowing Cold Air Intermittent
 

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

Poor Heat
 

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.

Poor Heat
 

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.