my 1989 f-350 7.3 idi non turbo seams to be leaking from the corner of the head and block on the passenger side. i changed a nasty ol thermostat thinking it might be trickling down but it is not. Im trying to get through to summer before taring it down to go turbo. My question for yall is have you had any luck with block sealers? I have some blue devil to try but am reluctant to use anything that requires the removal of the thermostat. Any input would be greatly appreciated.
thank,s
Justin

 

It's allegedly more common for the 6.9 to leak at the corners, but they are known to weep coolant or oil at the corners of the head. I wouldn't put anything in the coolant, that's just asking for more trouble. Unfortunately if yours is more than weeping the schedule may have been decided for you. Time for at least a top end rebuild. Good time to do studs as well.

 

do the studs and change out those HG's. I did it in a van, so this should be easy in a pickup.

 

I think its leaking from the thermostat again or atleast im hoping it is. im going to redo it and see what happens. im going to skip block sealers and do studs and gaskets if its still leaking.