When my son was driving his 2001 Accord the other day and again today when I warmed it up to change the oil, I could hear some clatter from the engine, more when the engine is warm, at idle, than when it's cold. I hadn't noticed it before, since I don't drive it much (and he doesn't have an ear for such things). It's not really too loud, but noticeable, and seems to not be as noticeable at 2000 RPM or more.

Not sure if it's valve noise (doubt they've ever been adjusted- what is the service interval for that?) or maybe worse, like bearings.

What would likely be the culprit for this type of noise on a 2.3 liter VTEC with 130K miles? once it warms up?

 

Actually wouldn't bearing noise get louder under load? This noise is when the car is in Park, so I'm thinking maybe noisy valves.

How often should the valves be checked for adjustment on this engine?

 

when my valves when bad in the car I had, it didn't make noise (or even smoke) till I gave it gas and was driving down the road. are you sure you think it's valves and not possibly your rocker arms?

 

...well, I say when they went bad.

Rather, when they started to make noise and let oil blow through.

 

FSM calls for valve clearance check at 105,000 miles or 7 years whichever comes first.

 

I went ahead and did a complete tune-up then checked the valve clearances. All of the valves were within a thousandth or so within spec so I left them alone.