96 Dodge Caravan knocking & rattling in front of van

My van has recently started this rattling/knocking sound in the front. It hesitates when I try to accellerate. I checked the oil and it was bone dry. I put more into it, however, I just put oil into it just a few weeks ago. My check engine light had came on for a short period (4 days), then went away. The engine oil light didn't come on, so I didn't think it was the oil. Glad I checked it. But what is causing the rattling/knocking sound? Why is it hard to accellerate? Since I have the noise, does this mean that the problem is seriously bad?

Worst case scenario, you ran the engine low on oil, damaged various parts of the valve train, lost compression from the cylinders, and there's your lousy acceleration. How will you know? Have a compression test done. Do you notice any oil puddles on the ground under the van? Are you seeing smoke out the tailpipe? Can you see black dots in the coolant?

Go to an Autozone or the like and have them read your fault codes with a scanner. It's free. If there's still a code it may lead you to a solution.

By "hesitate" do you mean the engine caughs when you pull away from a stop or do you mean it just doesn't feel like it wants to accelerate at any speed? If it's the later, the first paragraph may apply.