has good oil pressure and valves are quiet. the rapping noise comes from the lower part of the engine.
no i did not clear out the egr ports they were a little black but were not clogged. the noise does sound like it could be coming from behind the timing belt cover
the raps increase in speed and the rpms increase. but goes totally away at 1500 rpms. the noise does not increase in volume,(sound). and like i said when it first started doing it was intermitent. like maybe an ac compressor goes on and off
i sorry i don't understand how a bearing could be intermitent, going off and on like it was being switched. also i changed the oil maybe a 1000 miles ago and there was no metal fillings.