Knock on start

Have a Neon with a 2.0. Upon start up you hear a distinct knock. Limited to one cylinder. Sounds almost like a wristpin. It does speed up with increased engine speed. However if it was a wristpin or rod knock it would continue even when warm. This one goes away in about a couple of minutes. Is this something normal? Where should I look to find the problem? Is there something in the valve train that would cause this? Engine has about 75,000 on it and runs well otherwise.

Do you have oil pressure immediately on start up?
A partially plugged oil filter or strainer starting to plug up will cause low oil pressure.