2001 3.2 Rodeo tap on start

[Rmasters3]

My 100K engine taps on start-up--most noticable in the morning after sitting overnight. Sounds like a hydraulic lifter noise and it goes away after a few minutes driving and warmed up once. Don't notice it later in the day even if it's been sitting for several hours. Not severe, but it doesn't sound right.

I use synthetic 10-30 oil and a Fram Extra Guard filter on it with about 1,500 miles since last oil change. Had the timing belt and water pump changed about 6 months ago, I noticed this tapping this noise fairly recently. Any thoughts? Sticking valve? Wrong brand of oil filter?

Otherwise the engine runs smoothly and without a noticable changes.

[Cat Fuzz]

This engine doesn't have hydraulic lifters. The problem could be worn cam follower shims. The noise is probably going away after oil starts washing over the cam and followers.