I may be a little paranoid, but I've never heard this sound before.

I just did a coolant flush, and start the car up. Still warming up, I hear this "tock-tock" sound. It seems to be coming from the front of the engine around the water pump. Definitely sounds like something is rattling against another but I can't see anything. I get freaked out and the turn car off for a minute, then when starting again it's gone.

here's a vid: http://homepage.mac.com/jolocho/noise.mov
The fan is blowing into the mic a lot, but you can hear the ticking.

 

I would love to help but i dont have Quicktime and i wont get it just to hear your soundclips
Sorry

 

Can't really seperate out the noise you're talking about. Did you make any other adjustments, belt tension, etc.? Did you allow the engine to fully warm up and then top off the coolant?

 

I would love to help but i dont have Quicktime and i wont get it just to hear your soundclips
Sorry

 

when i did the cooling system flush n my 85 gs, it made the same noise. scared the ******* out of me at first, then it just went away. i figured it was just air in the system or something.

 

hmmmmmmmmmm.

After driving around and even after I let it cool off for about 5 hours I couldn't get it to make the same noise. Perhaps it was just bubbles coming out. Though it was a bit loud and didn't happen when I did the coolant last year.

trochoid, it's a "tick-tick" sound about every 2 seconds.