Ok guys...Ive been scratching my head for a week. Time to come to the forums and see what you guys can come up with that Ive missed. Just rebuilt the entire cooling system on the wagon. New water pump..new thermostat...new hoses, new radiator and new cap. Replaced belts while I was at it and also replaced the fan clutch since it was cheap. 440 engine. I noticed that the car heats up like normal to operating temp...but there is no pressure in either the upper or lower radiator hoses. The engine and hoses get hot..but the hoses are soft as if coolant is just barely running through them. I can pop the radiator cap off at full operating temp and there is no pressure release. However, once the coolant hits the air...it does overflow out. Radiator is full and car sits at 195ish at idle...maybe 220 on the freeway. Seems really odd to me that there is little to no pressure..but also no leaks. Doesnt seem to overheat - and if the thermo was stuck...it would run hot quick or not heat up at all. Could the coolant be circulating so well that it doesnt hold pressure because its cooling so well??? Heater doesnt work..so I cant test the heater. Ideas? I dont really care about the lack of pressure I just dont want to get a false sense of it running cool if its not. Guage reads 195 at idle all day..hits 220ish on the freeway but never pegs to 240. Runs like a champ otherwise. 220 isnt really hot for a big block...but i know it held pressure before. BTW - although the cap is new...I also put the old one back on as a test...no change...still no pressure. Ideas?? MOPAR GUYS...help!!!
Sounds like an airlock to me. Air trapped in the heater core. Easy to fix. Pull one of the heater hoses off and let it run until the water moves through. We usually drain and purge out the air in the cooling system with the heat set to high (open fluid flow). Since you're in AZ, your's may have been closed?
Try asking the new resident cooling expert. http://www.stationwagonforums.com/forums/showthread.php?t=16576&highlight=cooling
I'm with Stormin' Norman on this one LB72. Sounds like your heater'z got an air bubble. Hook up an 8" long piece of 5/8th" hose to both nipples on your water pump and go for a ride BTW, After 40+ years playin' with Mopars I WILL NOT USE ANY THERMOSTAT THAT I DON'T BUY DIRECTLY FROM A MOPAR DEALER AND I DON'T CARE IF IT IZ MADE IN MEXICO. NO THERMOSTAT I'VE EVER BOUGHT AT ANY PARTS STORE YOU CAN NAME WILL STAND UP TO AN O.E.M. T-STAT AND I DON'T KNOW WHY BUT I'VE PROVED IT MORE TIMES THEN I CARE TO REMEMBER Now go make that big wedge sing
Update: Found a blockage in one of the heater core hoses that flows through some temp control valve that I didn't replace...big chunks of sludge in the valve. Now I know where my muddy water is coming from..need a flush! Freed up the sludge and hosed some water through it. WE HAVE PRESSURE! Took it for a ride and it sticks right at 195. Solved another issue at the same time...always wondered why my upper and lower hoses sucked closed as it cooled down - they aren't doing that anymore. Must have freed up the ability for it to back flow as it cools now that the blockage is gone. Ahh...the joys of old cars - wouldn't trade it!
Glad you found the problem, LB! There's no better feeling than to track, find and solve an engine problem!:banana:
