[jomomma]

If that might be the problem on my van, but how could the system hold a pressure test for 3 hours as mechanic stated. Also I have noticed a rust bubble on the front of the rear passenger wheel opening ....about 8 inches up from the bottom of body. Do the lines run inside the body at the wheel well opening or under, around etc. Maybe this is indicative of leakage. I reckon I need to do some interior trim tear down and get this thing in the air and take a good look. Still, I am having no air lock problems with thermostat out, but no heat of course. Will check coolant levels tomorrow. Always dark when wife gets home. Also, can anyone tell me what the 3" heater valve that lives between the heater hose and heater core hose is for? No one has an answer. Could this be malfunctioning in not getting a true pressure test? One mechanic says it is some type restrictor to prevent a sloshing sound in the heater cores when first starting vehicle. Lastly, there are no wet carpet areas in the front or rear of the vehicle.

 

[marvinstockman]

Regarding your rust, I just looked at this issue myself, and it appears that the problem is the area behind, and inside the wheel well, where two panels are meeting. My guess is that, over time, the sealant has dried out and allows water in.

 

[marvinstockman]

Also, have you had your coolant tested for exhaust gases?

 

[jomomma]

Yes...numerous times and all come back negative.

 

[jee34]

Since your radiator cap has two valves,one could be defect,even if the cap is brand new.

 

[jomomma]

Latest update. Removed thermostat and ran for several weeks. this purged all air from system. Replaced with new thermostat and existing "New" radiator cap on Sunday 12-28. Drove Sunday and Monday. Noticed this morning, Tuesday, that overflow full and radiator down a little. Filled radiator and wife drove to work. Came home via expressway, only 7 miles, 40 degree day. Radiator fans blowing and radiator not hot but slightly warm on driver side and cold on passenger side. Car was idleing and slowly turned radiator cap to first notch. Air burped out of system and removed cap, hardly any pressure. Coolant was barely warm. Car ran for 5 minutes or so and thermostat was open, but not much coolant circulating. Plenty of hot air coming out of heater. No overheating by temp gauge. Dead on half way. Could not take a chance on getting air locked so I removed thermostat again. Thermostat was open and coolant was hot. Coolant flowed out of block which tells me not air locked, but if continued driving will probably get that way. However, by the fans being on, that tells me that there is an air bubble right under the coolant sensor. This has to be an issue where there is a vacuum leak during cool down. Coolant is not being drawn back into the radiator and is being replaced by air.. The only thing I can try at this point is to replace the coolant overflow line from the radiator to the overflow tank. So, what are your thoughts.

 

[The_big_dill]

The sound of one side of the radiator being warmer than the other tells me that there is some kind of obstruction. You said it runs fine when you take out the thermostat? If so, are you putting in the thermostat the correct way?

Furthermore, did this vehicle have stop leak go through its system?

The rear heater hoses are under the passenger side of the car on my 2002, they rust from the factory and had to cut mine twice to stop leaking.

 

[Mr. Fixit]

I have a 2002 Dodge grand caravan, 3.3 engine. 137,000 miles. The problem started 2 years ago when top radiator hose blew off going down highway. Filled coolant system back up and put a screw type clamp on hose. From time to time the hose would be very tight and system still was pressured even from setting overnight and would have to occasionally add coolant. This finally cracked the radiator neck and I had to replace it last week. All hoses, radiator cap,thermostat are new and water pump is not leaking and jetting water through radiator just fine. I have had to continually pour coolant everyday in radiator for the past month, even now after new radiator. The system is getting so pressurized that the cap is letting the pressure overflow into the reservoir and so much is being released that it is overflowing and blowing on the highway. The drivers underside is wet with coolant and the top hose is tight, even a day and a half setting. From what I have read I have had a suspicion that the head gasket is bad and exhaust gases are entering the coolant system thus forcing the coolant out. The system has been tested cold and hot and no leaks detected. So at this point I am sure this is a terminal situation and it is definately a bad head gasket. I have to add 1/2 gallon of coolant every day just for short trips to work. Would someone please confirm that this is the problem. If not, what else. I cannot afford to continue to waste expensive coolant every day and the vehicle is not worth a $3000 repair.
Jomomma

With everything you said there is two things you can do. run the engine and see if you can smell antifreeze in the exhaust. if so more then likely you have a blown head gasket. another thing you can do is loosen the belt and run the engine and if bubbles show up in the radiator you have a blown head gasket. the combustion chamber is pressurizing the cooling system sort of like an aerosol can. with 137.000 on the clock i would tear it down and replace the head gaskets. but that is just me. one more thing. take the plugs out and see if there is one or more that look bright white and clean sort of like it has been steamed cleaned this is a dead give away.

Hope this helps.

 

[Laramie3500]

Was there any resolution to this???

Did anyone resolve this issue? It appears to have stopped abruptly with no solution found. Was this a coolant return bottle issue or head gasket issue?

 

[mjfminid]

Make sure you have the correct water pump. If your serpentine belt goes around the water pump pulley with the grooved side of the belt on the pulley you need a standard rotation water pump. If the smooth back side of the belt rides on a flat pulley then you need a reverse rotation water pump.

 

[shuswap]

Old thread but this just screams of a air leak in the line from / to the overflow tank. I had to zap-strap mine at the rad...depsite it feeling tight it was leaking air rather than pulling coolant back into the rad.