mild valve tap noise

When I start the car, when its been sitting a while (engine ambient temp), and don't let it warm up for more than a 4-5 min.'s + I hear mild rhythmic tapping from the engine valve train area almost like the sound of a diesel until the engine becomes warm.

The car has 52K miles and has always been in for scheduled service.

Should I have any concern here? Is there any adjustments necessary??

The sound is mild and consistent and then goes away. Performance seems fine, there's no oil burning and I always use hi-test gasoline.

Response appreciated.