Engine Cooling problem

[989153]

I have a 65 coupe with a 302 swapped from the 289. I can’t seem to get it to cool. Replaced thermostat and just replaced the radiator. After a brief 5 minute drive it was too hot to touch. Any ideas?

 

[dennis112]

I have a 65 coupe with a 302 swapped from the 289. I can’t seem to get it to cool. Replaced thermostat and just replaced the radiator. After a brief 5 minute drive it was too hot to touch. Any ideas?

Were the head gaskets replaced?

 

[989153]

No

 

[dennis112]

Have you verified timing? If it is retarded or advanced too far it will run hot.

 

[989153]

I’ll check that tomorrow. (Obvious question) Would the water pump affect it

 

[dennis112]

I’ll check that tomorrow. (Obvious question) Would the water pump affect it

Not unless the impeller is not connected to the shaft. The stock water pump normally works quite well.

Corrosion can cause various cooling issues including blocked passages. Was there any sign of rust in the fluid when you replaced the radiator? Also did you use a 50% (or less) antifreeze/cooling mix?

When the radiator sits overnight (after being ran until hot) can you still see antifreeze in the upper tank? (An inch down is OK if the car is not using an external reservoir.) If the motor seems like its consuming the coolant, then there is a serious internal issue.

How is your radiator cap? Is your radiator still full? Any bubbles seen in the radiator when the cap is removed? Flow (agitation) without bubbles is a good sign.

If you carefully place your hand on the top tank and then the bottom tank does the lower tank feel cooler? (A cheap hand held inferred temp gauge would be safer.)

Is the car running lean? Could be an uncapped vacuum hose/bad carb.

 

[zookeeper]

Why are you touching the radiator? At the risk of sounding like a jerk, I'd go by the gauges before I started slapping my bare skin on things. 180° is hot enough to burn you yet perfectly normal.

 

[GOvert]

Is the thermostat in the 180 to 190 degree range? A common mistake I've seen many times is the thermostat will get replaced with a 160 or left out all together. Too low of a number on the t-stat doesn't give the radiator enough time to cool what is in it before cycling open again.

 

[2Blue2]

Things not mentioned yet

Fan Shroud?
W. pump intake hose collapsing
Radiator clogged with a fresh batch of scale from a motor thats been sitting
Vacuum leak on carb?
Carb jet partially clogged making lean condition
system not burped

Good luck keep us posted

 

[GOvert]

Impeller rotted away?