I took my car (03 S2k) to the dealer today because its been making a very loud rattling noise in the engine bay. It sounds like 2 pistons (or metal objects) are banging into each other constantly and its been doing it ever since I bought the car 2 years ago whenever I come within 2-3 thousand miles from a oil change. I brought to the nearby honda service center near my house about a year ago, which provides the WORST service ever and scams (They disconnected my battery halfway last time and told me I needed to buy a new one). They just looked at it and said it could be normal because s2000's usually rattle, and then blamed it on my fram oil filter. SO..Today, when I brought it to another dealership, they told me it sounded really bad. They are taking my engine apart first thing tomorrow because they say it sounds like a piston is loose and is banging against the valves or something. Anyways, the question I wanted to ask is...They say my extended warranty on the car may or may not cover the cost. The Honda extended warranty should cover this right? I just have a feeling that the dealer is going to try and make stupid excuses to void the warranty.

I know this is a long post, but I need your responses please.