Coolant escaping from the radiator cap

[anonymous-user]

I wonder if anyone has any ideas on this: I am seeing a small amount of coolant leaking from the radiator cap after shutting down from warm. I have replaced the radiator cap. The thermostat is working (top and bottom hoses are warm), as are the electric fans. I have run the engine to warm with the radiator and overflow tank caps off in order to purge air bubbles. There is no sign of coolant in the oil or white smoke from the exhaust (so I am hoping no head gasket damage). I suspect some deformation to the lip of the radiator aperture (although how this happened I am unsure).

The engine is a Chrysler 383 V8, with a newish uprated radiator and two Kenlowe fans. Thanks for any sensible ideas.

[GavinPearson]

Breadvan73 said:

I wonder if anyone has any ideas on this: I am seeing a small amount of coolant leaking from the radiator cap after shutting down from warm. I have replaced the radiator cap. The thermostat is working (top and bottom hoses are warm), as are the electric fans. I have run the engine to warm with the radiator and overflow tank caps off in order to purge air bubbles. There is no sign of coolant in the oil or white smoke from the exhaust (so I am hoping no head gasket damage). I suspect some deformation to the lip of the radiator aperture (although how this happened I am unsure).

The engine is a Chrysler 383 V8, with a newish uprated radiator and two Kenlowe fans. Thanks for any sensible ideas.

You probably have too low a concentration of ethylene glycol (eg) in your mixture, so it crosses the vapour line at too low a temperature. Once the engine shuts down and the heat soaks in, you are probably getting local boiling, manifesting itself as a leak from the cap. Clean the cap, make sure the sealing surface is OK, and put in a higher quantity of eg and you should be OK.

[anonymous-user]

Thanks, I shall see what effect adding more glycol has.