Can anyone explain a strange coolant leak on a 450 SEL 6.9. Everything runs fine however if I run the car for about 10 + miles (basically warming it up to 175F) then return home I seem to develop a coolant leak about 20 hours later? I have checked it when it is running and all appears fine, after stopping the coolant does not leak, and seems to maintain pressure. I am trying to determine the area of the leak but haven't been able to witness it yet. I did a bulb test and it appears to be very low on antifreeze would this be an issue? I will replenish the antifreeze level but would like to determine the leakage area first. Any suggestions, why the delay? I can only assume that it is a slow leak somewhere causeing it to pool somewhere?
Drew