Well mine was pretty loud ticking but I have been through this before and I think my issue is that either my piston rings are toast and I have blowby or my turbo seal needs fixing, I have noticed some smoke also at high boost which may be due to the same issue.

I have also had a loud clacking sound on my 3000gt which would not disappear and would change with speed, that unfortunatley was a bent valve due to piston slapping it. I would def. do a compression test to see if you have good compression across all cylinders, it is easy to do and the comp. gauge is not that hard to find at Kragens.

 

update.

after bitching about the crappy dipstick, i couldn't get an accurate reading. so, i poured in a quart and checked the readings periodically... wipe, slide, wipe, repeat and still couldn't get a conclusive reading after 3 quarts in. then, i just slept with a bottle of fat tire brewski.

the next morning which was today, i checked the dipstick and got an accurate reading on the blank side (opposite of the etched side). it was overfilled with 2 quarts or so... so i removed 2 quarts. all in all, i was missing 1 quart max.

anyway, i drove the car and the ticking minimized a bit... but as i went on the freeway onramp, the ticking sound started to become very consistent in amplitude. double yoo eff tee ate, mate? then i started to limp home... and the drastic happened. i started to get LOUD SQUEEKS along with the light ticking. double yoo eff tee ate, mate again?

well, i am now home... going to tow the car to GTM and diagnose the problem. depending on the situation, looks like i'll have to sway from the g. i just hope that won't be the case.