Since I'm away at college, my car sits outdoors in a parking lot overnight for the first time ever (had a warm garage back home). It also get's colder up here...

Anyways, I've noticed that I can feel and hear a thump right at the beginning when I start the car in the cold, after it's been sitting overnight (about 30-45 degrees cold).

I found a TSB, but no actual info:

00-059 FEB 02 Engine - Thump Noise at Cold Start

Does anyone have the actual info on what's causing this, or if it's normal? It doesn't really bug me, and the car starts just fine after the thump, I just want to make sure it's normal...

This is for an '02 Accord LX 4cyl BTW...