4Y has strong/loud tappet noise

[cat007]

I think it's tappets. It happens when you first start the car - then goes away after about 5 seconds. If the engine is hot and you lower the idle either by riding the clutch etc, the noise comes back.

I'm thinking of changing to a more viscous oil - cant remember off the top of my head what I'm running at the moment.

Is it worth taking the cam cover off and adjusting the tappets?

Sorry if this seems like a silly question