1968 Charger Overheating

[flathead1946]

I'm having a problem with my charger over heating and blowing off the top radiator hose. Engine had been completely rebuilt, (440) less thank a 100 miles on it. While drive last week, I let off the gas to exit the freeway and the engine popped loudly and started steaming and died. I coasted over the the side of the road and when I checked the engine out the top radiator hose had popped off. Stock type hose clamp. Trailered home. It has a 190 degree thermostat and the engine temp never got above 200. Saturday I took it out for a drive to check it out. Again the engine temp never got above 200, it was 92 degrees out. When I let off the gas to turn into the the subdivision it popped once and started steaming again. coasted home and filled with water and put the hose on. while turning the motor over it fired then died but with the hood open and radiator cap off I saw water bubbling out of the radiator. My guess would be head gasket?? with less then a 100 miles can it be re-torqued or need to be replaced? or is it something else? No water in the oil. Thanks for any advice in advance

[Cooter]

Just FYI, you say 'water' but I assume you mean coolant mix as I never run straight water.
If your building pressure in cooling system, then your getting combustion gasses from somewhere.

[nihil]

I recently sorted out a persistent overheating problem on my `68 with a 440, somewhat by accident. This past fathers day, I was determined to take the Charger out for a drive since it was my fathers, and a small vial of him is hanging from the rear view mirror since there's no other place in the world he would rather spend his afterlife (he bought her new and loved this car). That morning I went to bypass the heater core to address a small leak that developed last time I drove it, check fluids, etc..

Previously in my attempts to chase overheating issues I have replaced the rad (new OEM style), new high flow water pump, flushed the cooling system, run with several thermostats, run without a thermostat, tried different mechanical fans (5 to 7 blade I think it was), etc...  Last time I swapped the fan, I also swapped the fan clutch out of desperation since I had another good one laying around. It didn't seem bad, but I had tried everything else so why not. Didn't change a thing.

During my fluid and bay check on fathers day, I noticed that fan clutch had some play in it, so I headed down to Napa and picked up a new one, and grabbed a generic $114 16 inch Flex-A-Lite for another one of the cars while I was there.

Went to put the new fan clutch in, and found it had a different thread than the old one, and I didn't have enough of the correct sized bolts laying around. Being a Sunday, and getting pretty late, finding the right bolts was going to be a bitch. Being determined to at least take a short drive for fathers day, I pulled the shroud, spaced out the water pump pulley bolts with a couple washers, and wired up that 16 inch electric fan, offset to the passenger side so the back would clear the water pump pulley.

I figured I'd make it around the block a few times, then she'd get hot and I'd have to come home. The first lap around the block the temp jumped to 220'ish as it burped some air out of the system from the heater core bypass. After that, she went back down to the 180 that is spot on for the thermostat I put in there last. Making wider and wider circles around "home base", that needle didn't budge. Being completely blown away, I laid into her a bit, trying to get the temps up, but nothing. Over 3/4 of a tank of gas later, I came home and wired a switch to the relay on the fan, and I plan to leave it there.

I've never known her to run this cool and have the temp remain so stable for so long. I'm 100% sold on electric fans now, and was blown away that a cheap generic application fan that I was going to put on a little 3 liter diesel worked so well to address a problem I had been chasing since she came into my care.

The fan mount is a zip tie style mount that poked through the rad fins, pulling the body of the fan close to the core. Because of that, and having to offset it from the water pump pulley, I'm leaving the factory shroud off (the fan has its own little shroud). The fan pulls the same amount of air through when it's moving or sitting still, and when moving the open spot on the drivers side gets free flowing air, aiding the cooling process under load.

I don't care much for the way it looks in the bay, but it sure as hell does keep her running cool, and that's more important.

[Back N Black]

Maybe the heater core is plugged and when you by passed it the car ran at normal temp? 

[Cooter]

Maybe the heater core is plugged and when you by passed it the car ran at normal temp? 

heater core plugged wouldn't cause it to overheat, just no heat. Water would just bypass the heater core and back in engine. Like it was blocked off.

I think a new fan clutch would have done the trick as it's obvious the above car had an air flow problem, but an electric is working for him so....

[nihil]

Maybe the heater core is plugged and when you by passed it the car ran at normal temp? 

heater core plugged wouldn't cause it to overheat, just no heat. Water would just bypass the heater core and back in engine. Like it was blocked off.

Yep, it's now just as blocked as it would be any other way.

I think a new fan clutch would have done the trick as it's obvious the above car had an air flow problem, but an electric is working for him so....

I tried 2 or 3 fan clutches, and thinking it was an air flow issue I even went as far as removing the A/C condenser. I'm not saying electric fans are a magic bullet, the mechanical setup obviously worked great at some point in time, but it sure did the trick in my particular case.

[firefighter3931]

I'm having a problem with my charger over heating and blowing off the top radiator hose. Engine had been completely rebuilt, (440) less thank a 100 miles on it. While drive last week, I let off the gas to exit the freeway and the engine popped loudly and started steaming and died. I coasted over the the side of the road and when I checked the engine out the top radiator hose had popped off. Stock type hose clamp. Trailered home. It has a 190 degree thermostat and the engine temp never got above 200. Saturday I took it out for a drive to check it out. Again the engine temp never got above 200, it was 92 degrees out. When I let off the gas to turn into the the subdivision it popped once and started steaming again. coasted home and filled with water and put the hose on. while turning the motor over it fired then died but with the hood open and radiator cap off I saw water bubbling out of the radiator. My guess would be head gasket?? with less then a 100 miles can it be re-torqued or need to be replaced? or is it something else? No water in the oil. Thanks for any advice in advance

I'm not a fan of those silly factory spring style hose clamps. Put a real hose clamp on there 

Cooling systems are designed to operate under pressure. Coolant will boil if pressure is escaping. My guess is that your problem lies with a poor seal on the rad hose.



Ron

[Highbanked Hauler]

I'm not a fan of those silly factory spring style hose clamps. Put a real hose clamp on there.

  Got that right, I have had the top radiator clamp break and both on the line going to the fuel pump so I changed all of them and put in stainless steel screw type.