One problem related to engine knocking noise has been reported for the 2009 Honda Odyssey. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2009 Honda Odyssey based on all problems reported for the 2009 Odyssey.
I just purchased this vehicle on April 19, 2016. I had the oil changed mid June. My wife had a trip to florida near the end of June, so I checked the oil and it was fine. As of today I heard a knocking sound and checked the oil. It was two quarts low. I filled the oil and the knocking sound remains.