You are not the only one. It seems to also happen on the 1g 2.5l. I have been adding long life oil (designed for high mileage engines) and it has seemed to help the issue. This oil helps to swell the gaskets to seal off anything that has loosened up over the years.

I believe it to be due to engine age, things loosening up and gaskets, rings, etc wearing down.
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2000 Stratus ES / V6 / Leather / Tint / 173,500mi
2003 Town & Country Limited / V6 3.8 / Heated Leather / Auto A/C / DVD / 102,000mi