i have 2010 odyssey with pinging noise on acceleration goes away once car is moving really loud up hills, dealer says its the poor quality of gas try higher octane i did to no effect any suggestions as to cause
Some have had success doing this with seafoam and a direct line into the intake (google it, it's discussed on just about every car forum) but this solution is not for everyone. You should have some mechanical skill and knowledge before performing.
I had the same issue on my 2010 Odyssey. Pinging was occurring between approx 1700 and 2200 rpm. I noticed the rattling sound since the beginning, but it wasn't until about 20,000km that I took it in to have it checked. It took 2 trips to the dealership to get it fixed... The first time, they looked at it for about a day, not sure they did much, and said to use higher octane gas -- which might have helped a little bit, but did not resolve the problem. The second time, they kept it for about 3-4 days, adjusted the valves, and the pinging is a distant memory now. I didn't see the work order or any paperwork, so I don't know exactly what was done.
Hopefully your Odyssey is still under warranty. Take it in to the dealer again, filled with the higher octane gas to show them that the problem is still there, and ask them to fix it properly. Pinging on the Odyssey is not common, but it obviously can happen.