Should you wait until you hear "tapping" to adjust your valve clearance ?
Daniel B. Martin or anyone ?
Thanks.

Yes.

Nissan does not include valve clearance adjustment with any scheduled maintenance. It should be done if and when the valves become noisy. On most cars this service will never be needed.

Adjusting valve clearance not as simple as turning an adjustment screw. Each cam lobe bears directly against a disk-shaped steel shim of precisely machined dimensions. Changing valve clearance is done by removing the shim and substituting another with a different thickness. The shims are made in a variety of thicknesses. They can be purchased from the dealer. I'm not aware of any other source for these shims.

According to the service manager at Santa Monica Nissan, Maximas come with self adjusting valves. My question: why the hell are they so noisy then?

Was this service manager referring specifically to the 4th Generation Maxima engine, the VQ30DE engine? If so, he is misinformed.