Chrysler Repair: knocking in engine, chrysler town and country, best guess

Question
The other day I was driving our 2003 Chrysler Town and Country, go home and turned off the engine.  I went back out and heard this knocking noise.  When the car is in park and idoling i do not hear it. But between 0 and 30 mile per hour you hear it. There is nothing else wrong.  The transmission is fine no issues shifting, the engine does not over heat nor is there anything in the oil.  There is about 106,000 miles on the engine.  what could be the issue.

Answer
Diagnosing a noise really requires that the person be present to be able to pinpoint it's location and cause. But with that said, I'll try and give you my best guess. If it also makes a clanking or screechy type of noise while you are starting the van then you may have a broken flexplate/flywheel. That's the best I can do. Hope it helps.