Noise at 1500-2000 RPM

[F-22 Raptor SHO]

the automatic SHO's are equipped with a timing belt tensioner that keeps the tension on the belt using a pulley on a fulcrom that is kept taut by a small hydrolic piston. The piston goes bad over time and the timing belt gets slack. The reason you get this noise is from a combination of two things: 1: because the timing is off, the number 1 cylinder detonates out of time...secondly, the slop in the timing belt causes the belt to flap against the upper timing belt cover. The reason the noise goes away at higher rpms, is because the belt starts to tighten up the slack a bit as rpms rise.

 

[mclarida]

The sound is almost metallic and is in the rear(near the cylinder #1) however does not sound like the normal detonation. I know that you heard/saw the video so If that is what you think then I cannot argue(as I just want it fixed). I feel foolish as I did not think It would go bad(the pison). The sound is loud(at certain rpm range). The belt does have slack(some at the top) so I know it need to be fixed. Where can I get the tensioner piston only? I have two bearings now and two tensioner arms. I was able to push the piston down. Any ideas where I can get a piston? Let me know-
Mike

 

[F-22 Raptor SHO]

check here on the forum in the for sale ads....post in the wanted to buy section, or go to a junk yard