2003 Ford Navigator Engine cooling Problems

“03 Navigator began stuttering when driving, felt like a transmission slipping. I took it to the dealer and they said three of the eight cylinders were not at full compression. He advised new heads were needed. Cost: $7000. Several service bulletins have been issued on the problem, independent (former Ford tech) mechanic looked at the problem. He advised this is very common on the tritan motor and there is a casting problem with the heads.”

“2003 Ford expedition xlt with 5.4 liter triton v8 engine with 59,000 miles. The vehicle is well maintained and not abused. The #3 spark plug was blown out of the aluminum cylinder head during driving at approximately 5 MPH. This event was preceded by a tapping noise which occurred over the preceding two weeks. The noise was similar to a noisy valve lifter. The engine had the original factory installed spark plugs that were never removed, replaced or serviced. The factory change interval on the plugs is 100,000 miles. …”

“- the contact owns a 2001 lincoln Navigator. On 3 different occasions the spark plugs exploded, and she has had to replace the spark plugs and coils. The contact stated that when the spark plugs exploded they sent sends the fragments from the spark plugs into the engine. Each time this happened the number 3 and number 4 sparks werethe ones that exploded. While driving approximately 65 MPH on january 11, 2007 it was the most recent incident. She had to have the vehicle towed. The contact stated that the vehicle has been with the mechanic since 01/11/2007. …”