1966 coronet overheating

[jsrod21]

my 66 coronet is overheating, new thermosat replaced it twice actually, heater is not working, so im not getting any flow through it, car is an A/C car with a heater bypass valve, if that valve is closed will it over heat the car, or is my heater core plugged up? Any help would be greatly app.

 

[eagleone1983]

Even if your heater core was plugged you should still be getting flow through the engine. Is the top radiator hose hot?

 

[Durandal25]

my 66 coronet is overheating, new thermosat replaced it twice actually, heater is not working, so im not getting any flow through it, car is an A/C car with a heater bypass valve, if that valve is closed will it over heat the car, or is my heater core plugged up? Any help would be greatly app.

....also, if unsure of the temp reading get a laser temp tool. I had a similar issue with my 69 Bee and shooting temp readings all over the engine was really handy. $60 bucks well spent.

 

[jsrod21]

top radiator hose is hot the radiator is not. I thought maybe the radiator was plugged. Bypass valve came up because a guy I know was swearing that the bypass valve was stuck shut. I did laser temp the engine and it is hot it runs up to 230 with a 180 thermostat in it. im going to take the radiator in and have it cleaned and see what happens.

 

[kb67mopar]

top radiator hose is hot the radiator is not. I thought maybe the radiator was plugged. Bypass valve came up because a guy I know was swearing that the bypass valve was stuck shut. I did laser temp the engine and it is hot it runs up to 230 with a 180 thermostat in it. im going to take the radiator in and have it cleaned and see what happens.

If the hose is hot and the radiator is cool its more then likely plugged internally as you have mentioned.

 

[terzmo]

my 66 coronet is overheating, new thermosat replaced it twice actually, heater is not working, so im not getting any flow through it, car is an A/C car with a heater bypass valve, if that valve is closed will it over heat the car, or is my heater core plugged up? Any help would be greatly app.

at idele/in traffic or running down the road ? If both....rad is suspect if after the thermostat opens..thermostat could be stuck if it overheats within 10 minutes or so of startup. On startup..watch temp gauge as it climbs and it should relax to a lower temp when it opens..if it goes directly to overheat,the stats not opening.If it drops and then climbs to overheat..waterpump issue. If overheating at idle/intraffic only,but good down the road the rad is not getting enough airflow...fan/shroud

 

[godfatherofchry]

my 66 coronet is overheating, new thermostat replaced it twice actually, heater is not working, so im not getting any flow through it, car is an A/C car with a heater bypass valve, if that valve is closed will it over heat the car, or is my heater core plugged up? Any help would be greatly app.

put a bottle of liquid cascade in ti and run it for a week or two then back flush it with thermostat out the whole system will be good as new.........Artie

 

[jsrod21]

it takes 25 min or so its a gradual overheat. I changed the thermostat out thinking maybe it was a problem. heats up quicker if its going down the highway versus in town driving, I took a good flashlight and drained the radiator down and most of the coolant passages in the radiator that I can see are plugged. Ive never heard of the cascade trick, I may give that a shot, wheres a good place to get a radiator, oriely and napa online doesn't seem to list anything for the 66.

 

[krowbar]

it takes 25 min or so its a gradual overheat. I changed the thermostat out thinking maybe it was a problem. heats up quicker if its going down the highway versus in town driving, I took a good flashlight and drained the radiator down and most of the coolant passages in the radiator that I can see are plugged. Ive never heard of the cascade trick, I may give that a shot, wheres a good place to get a radiator, oriely and napa online doesn't seem to list anything for the 66.

I bought an aluminum 3 row 26" on Ebay for about $200. Works and looks great. Champion brand. It's in my 67 coronet 440cubes. If you're wanting it to look factory then either flush maybe recore yours.