ok i have a 1999 6.5l td after turning the engine off you get the faint smell of antifreeze. the operating temp is right at 200 and jumps to about 210 right when the thermostat seems to open. sometimes when i turn the engine off antifreeze comes out of the overflow hose on the expansion tank. no smell of antifreeze inside the cab of the vehicle and no puddles under the heater core on the passenger side. any insight on thoughts of what it might be? thanks mike

 

Do you have normal pressure in the coolant system? Have you noticed a loss of coolant or had to add some periodically? Could be a small leak in the radiator, bad cap, loose clamp, etc. Mine started doing that recently and it was the first sign of the #8 cylinder issue rearing it's ugly head.

 

Do you notice any white smoke from the exhaust?

One morning start it up for 60 seconds, turn it off then remove radiator cap. Is there any pressure?

 

it was the radiator cap.