Time for a rebuild?

[gsloth]

I'm looking for some insight on my Hellion T76 cobra. The motor is stock and has 49k miles on it, with only about the last 500 miles with the turbo. Before the T76, I had a KB 2.8H running 20psi on 93 octane for the last 10k miles. I thought I noticed a tick this summer, but everyone thought I was crazy and said it was just the injectors. It has been really cold here lately (OH), and the car now has a definite concerning tick that quiets down once the motor warms up, but never goes away completely. I had it compression tested last week and all cylinders were ~169, except cylinder #5 with 120. Those were all dry numbers, a bit of oil bumped up cylinder 5 to 140. What do you all think, compression test showed nothing catastrophic and I would hate to spend more money this soon, but im pushing 720hp through it and I'd like to salvage everything from my motor before it really pops. Suggestions welcome.

Video of noise
[ame=http://www.youtube.com/watch?v=VV8V92Pn5Hc]YouTube - tick[/ame]

 

[duomaxwell]

Could be one of two things.
1. Engine is cold and oil has had time to drain completely out of the head, what you hear is a dry valve train and on cold days is considered normal. (as long as after the engine warms up the noise goes away, which in your case it dose)
2. You have what some 03’ owners call “the head tick”, which I believe was a faulty lifter or valve lash adjuster. I do not know how to fix this but if you search for “head tick” you will find the answers you want.
PS. OHIO weather sucks!