rbrad9753

1999 GT, Convertible, Automatic, 60k miles.

Here is a strange situation that I'm hoping that someone can help me out. The other day I changed the oil and plugs. When I was done I started the car and it idled for about 15 seconds until a very loud knock appeared and I immediately shut off the car. The knock was definitely in the lower end and it really sounded like a rod broke. I started second guessing myself about the plug install, so I removed all of the new spark plugs and replaced them with the old ones that I removed earlier. I restarted the car and the knock was still there. I then decided to have the car towed that night to the Ford dealer to have it diagnosed. The dealer had the car for about 3 days and they told me that without tearing down the engine that I had something serious going on in the lower end of the block. The service manager, who is a friend of mine, was trying to work a deal with ford to split the cost of replacing the motor. While waiting for an answer from Ford, the mechanic decided to bring the car back into the shop and put a camera into each cylinder to look for any obvious damage when all of a sudden, when he restarted the car, the knock disappeared completely. Everyone is scratching his head over this one. They drove the car for about 25 miles and the noise never came back. I picked up the car last night and drove it home without a problem. Does anyone have any idea on what happened? This knock was so loud that I thought the rod was going to come through the side of the block. I have no idea what was causing this noise and why it went away.

Thanks,
Robert

starcam

Wonder if they checked cylinder compression before you left?
Bad gas, there could be some nasty gas if ur near E.

rbrad9753

The car had about a 1/2 tank of gas and we had no problems whatsoever prior to the knock suddenly starting.