whats your build date/ miles?
talk to chris, he had this corrected.
(post form yellow02gt on corral forums)
When the hood is open, the car purs quietly and you hear
no ticking or anything. Once you shut the hood, you can hear
a ticking noise from the left side fenderwell. If you put the car
up on a lift, you can hear it even louder from the left side
around the transmission housing. According to the dealer,
Ford has just released a TSB for this problem. There was a
manufacturer defect with something in the timing gears or
drivetrain assembly on 2003 Cobra's. This same Cobra, from
what I was told, was also very weak. They said the car feel
off in power and they couldn't figure out the problem until just
the other day. The car went in for some work, they ran the
VIN for any TSB's, and none showed up. They had to order
parts and when the parts showed up they installed them and
reran the VIN for any possible TSB's. The service advisor told
me that the TSB states that the left cylinder head needs to be
replaced to correct this problem. After they fixed the problem,
they road tested the car and the power was 100% better
than before.