I recently replaced the timing gear/chain in my1991 SAAB 900 Turbo. After driving for about 5000 miles I now have a loud chatter in the (I think) intake cam side of the engine. I have checked the chain and it is still tight. Chatter not present when first starting but as oil warms up it gets progressively louder. Seems to go away at about 2700 RPM but not certain due to the overall noise of the engine. It is relatively quiet at idle and begins to rattle at 1800 RPM. Had pressure checked and it is 60PSi when warm and chattering. Checked bypass valve near pump and it is clear. Suspect some type of slightly moving debris in the engine oil system near the port that leads to the intake cam (maybe metal flake or silicon sealant (used very sparingly when reassembling engine)). Your thoughts?

Optional Information:
1991 Saab 900 Turbo 2.0 L

Already Tried:
Drained and refilled with new higher viscosity oil. Drained system, added diesel fuel as lubricant and idled engine to try to dislodge foreign matter. Drained and refilled engine with 20W50. Still rattles.