H
HHGT
Guest
While on another forum, a thread got started questioning the upgrade from a Z06 to FGT. Supposedly by a guy in Huntington Beach California - I know it's not you Dennis since your car is in for the half shaft repair. In any event, one of the guys posted a response with a potential problem waiting to happen in the GT.
This is what he states: "Wait til they get some miles on them" he went on to say;
I sold my '03 Cobra with 28,000 miles on it to my buddy in April after buying my C6Z06. He put another 3,000 miles on it and loves the car. However, he recently had a mishap that is going to cost him a bundle and had necessitated the replacement of the motor.
What happened is that a spark plug came loose and worked completely out of its hole in the cylinder head. The constant bouncing up and down, caused by the up and down stroke of the piston, broke all of the porcelain off of the plug (top and bottom insulators) and the lower electrode broke off as well. All of this debris was sucked back into the engine and severely scored the cylinders and damaged the top of the piston. A few of the other spark plugs were finger loose!
It turns out that this is a known problem on the 4.6L and the 5.4L supercharged engines and gets worse with increased boost or NOS. By the way, my buddy's car has neither increased boost nor NOS. Apparently, this problem relates to the small number of threads in the plug holes and the low torque specs due to aluminum heads.
Some of the guys on the SVT forums recommend checking plug torque every couple thousand miles. The FGT could very easily begin suffering from this issue once they rack up enough miles and/or get modded with pulley upgrades and increased boost. END OF QUOTE.......
Attached is the picture he posted.
Any previous Cobra SVT owners that have heard of this and has anyone checked their plugs? Any service bulletins?
This is what he states: "Wait til they get some miles on them" he went on to say;
I sold my '03 Cobra with 28,000 miles on it to my buddy in April after buying my C6Z06. He put another 3,000 miles on it and loves the car. However, he recently had a mishap that is going to cost him a bundle and had necessitated the replacement of the motor.
What happened is that a spark plug came loose and worked completely out of its hole in the cylinder head. The constant bouncing up and down, caused by the up and down stroke of the piston, broke all of the porcelain off of the plug (top and bottom insulators) and the lower electrode broke off as well. All of this debris was sucked back into the engine and severely scored the cylinders and damaged the top of the piston. A few of the other spark plugs were finger loose!
It turns out that this is a known problem on the 4.6L and the 5.4L supercharged engines and gets worse with increased boost or NOS. By the way, my buddy's car has neither increased boost nor NOS. Apparently, this problem relates to the small number of threads in the plug holes and the low torque specs due to aluminum heads.
Some of the guys on the SVT forums recommend checking plug torque every couple thousand miles. The FGT could very easily begin suffering from this issue once they rack up enough miles and/or get modded with pulley upgrades and increased boost. END OF QUOTE.......
Attached is the picture he posted.
Any previous Cobra SVT owners that have heard of this and has anyone checked their plugs? Any service bulletins?