First time user,
My son has a 88 Mustang 5,0 We had to bypass the heater core after completing this job the engine over heats. The first thing I thought of was an air lock in the system so we refilled and also filled the top of the engine through the top rad hose but the problem is still there, the second thing we did is remove the thermastat in case it was defective but still overheats.
With the engine cool we started the engine and filled the rad as needed also noted the water in the rad was turning warm and circulating.
Any ideas PLEASE HELP........THANKS