Knocking Noise On Start Up

[love my ride]

This might be obvious to some but I recently picked up a 2001 ES300, sold car all the way around. On start up in the center of the front valve cover there is a knocking sound that you only hear for a few seconds and then goes away. If the car sits for an hour it does not make this sound. Over all the car has great power, rides well. the previous owner says it does burn oil and it has a valve issue. 164,000 miles. Any thoughts??

[landar]

It is probably starving for oil in that particular area at startup and/or has a sloppy valve clearance to aggravate the situation. Could be partially plugged oil passages. Pull the valve cover on the front and have a look.