As I informed you before, my H22 makes this sound at 1000 RPM: http://www.volny.cz/veitel/prelude/vtec.mp3.

As some of you advised me, I have made the auto to manual tensioner conversion on my H22 and the f*cking noise is still there!!! Some basic facts:

1) The sound comes only at approx. 1000RPM, nowhere else.

2) Exactly the same noise made my previous F22, at 1000 and 1800 RPM (there was no auto tensioner).

3) The timing belt does this sound, NOT the balancer belt (I have removed it and tested). It is also NOT PS pump, alternator or A/C.

4) The tensioner and adjusting pulley were replaced for the manual H23 one.

5) When I set the timing belt tension according to the Helm's, the belt is pretty tight (same as with the autotensioner) and the sound is there (again same as with the autotensioner). When I make it little loose, the sound dissapears, but the belt vibrates a bit (about +-0.5cm, it is 1cm on its "longest way" - between the exhaust camshaft and crankshaft).

What can it be? Water pump? The pump has 50,000miles (80,000km). Somebody told me that the water pump is "oiled" by the antifreeze. My coolant is not exactly 50:50, maybe it is 30:70 (more water than antifreeze). Can this do that?