69’ 429 Thunder Jet keeps overheating

[Wtyler55]

What’s going on everyone? Having overheating issues with my Bird. It does great on the flats and even in town, but when I hit a hill doing 60MPH or more, the temp gauge starts climbing. New pump & new radiator core this year and I’ve even pulled the thermostat. Any suggestions?

Thanks

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[Excaliburss]

Sounds like a small issue with one of your head gaskets. Get a pressure test

 

[OneAmongOthers]

What’s going on everyone? Having overheating issues with my Bird. It does great on the flats and even in town, but when I hit a hill doing 60MPH or more, the temp gauge starts climbing. New pump & new radiator core this year and I’ve even pulled the thermostat. Any suggestions?

Thanks

Did you properly "burp" the radiator to get all the air out of the system? First test... Turn on your heater. Do you get any heat from it? Another issue like mentioned could be a head gasket. There is tester like mentioned which can tell if your head gaskets are leaking. Though if it was a head gasket it would overhead regardless of speed pretty much. First see if you got air in your cooling system. Move on from there. Also make sure your radiator is filled all the way up. Have you replace the clutch fan? It could be another possibility. Big block motors will always run higher than smaller engines. You can also try a lower temp thermostat too. Don't run without a thermostat! Your car will not properly cool itself without one.

 

[DEVIL DOG 62]

Replace both your radiator hoses also. The older hoses came with wire or metal coiled through it. Hence the ribbed hose look. When a radiator hose gets old that metal will bust apart and cause the hose to flatten out when it's heated up. Even the newer hoses without the metal will do the same thing when they get old and worn out. They will flatten out under high temps causing the coolant not to circulate causing overheating

 

[Wtyler55]

Thanks for the ideas, folks. Radiator has new hoses, has been "burped" and turning on the heater is like a blast furnace. Haven't tested the fan clutch, but that would only affect the heat at lower speeds. I do need to re-torque the head bolts, but no water in the oil or compression loss. I'll torque them tomorrow and get back to everyone, but keep those suggestions coming. Hoping to drive from Oregon to Illinois next week.

 

[OneAmongOthers]

Have you tried replacing the temapture sensor? Perhaps it’s reading wrong?

 

[jazbo]

What’s going on everyone? Having overheating issues with my Bird. It does great on the flats and even in town, but when I hit a hill doing 60MPH or more, the temp gauge starts climbing. New pump & new radiator core this year and I’ve even pulled the thermostat. Any suggestions?

Thanks

Did you accidentally put in full strength coolant rather than 50/50?

 

[DEVIL DOG 62]

Thanks for the ideas, folks. Radiator has new hoses, has been "burped" and turning on the heater is like a blast furnace. Haven't tested the fan clutch, but that would only affect the heat at lower speeds. I do need to re-torque the head bolts, but no water in the oil or compression loss. I'll torque them tomorrow and get back to everyone, but keep those suggestions coming. Hoping to drive from Oregon to Illinois next week.

I don't think 69's came with a fan clutch. Just fan mounted on the front of the water pump. I might be wrong

 

[OneAmongOthers]

I don't think 69's came with a fan clutch. Just fan mounted on the front of the water pump. I might be wrong

1969 defiantly has a fan clutch. I just replaced the one on mine.

 

[Dozertech]

Just fired up my newly purchased 69 after it was stored for 40 years. The seal under my radiator cap was deteriorated terribly causing my overheat. Used a known good cap from a running vehicle. Problem solved