I have searched for this and have really found no definative answer. It could be anything from a lifter to a pushrod to a rocker arm to the oil oring. My ticking noise is audible at cold start after about 10 secs. Hangs around, if driving, for about a mile or 2. It ticks one sec. and the next it is gone. Then once the engine is warm all the usual ticking (sewing machine) noise starts. Now here is the odd part. If I rev the eng to 4500 or run the car hard thru the gears the tick comes back and stays for about 15 to 30 secs. Then it disappears. It is on the passenger side. I can not hear it very loud in the engine compartment. It is the loudest at the fenderwell and under the car. I took a stethascope and probed around and could hear it the most in the header collector and the x-pipe. It seems to echo and travel down the exhaust pipe. I listened to each header tube individually and it sounds like the last cylinder on the passenger side.

I noticed this this morning when I was speeding from a traffic light thru 2 gears shifting at around 5000 and quickly pulling in to get gas. When I pulled into the station the ticking was extremely audible. After pumping gas on the restart there was little to no noise.

This is a 2000 Formula with 61000 miles. To my knowledge the engine has never been messed with. I changed my oil about 200 miles ago and had no needle bearings on the magnet.

The tick seems to be the most audible in the collector, but there is no carbon buildup from a leak. Anyone have any ideas or possible culprits??

 

Piston slap would be my guess, but it could also be a rod bearing. Did you listen to all of the injectors with the stethescope? First thing is to determine if the tick is at cam speed or crank speed. Cam turns at half the speed of the crank. That will help you issolate it to the top end or low end. If you can't tell what speed it is, you should be able to find a mechanic that can.