I have a1996 Ford Explorer that has a hard time starting. Have replaced the computer, water pump, crank sensor and mas air flow unit. Water temp gauge flutates and steams sometimes out of the tail pipe. Thought it might e a head gasket leak but if motor starts vechile runs strong. Have put in head gasket/block sealant. Once truck is started and has started and warmed up will continue to start until motor cools off.HELP