Toyota Repair: Camry engine pinging, toyota camry xle, customer service person

Question
Dear Ted,

Just purchased a 2004 Toyota Camry XLE and it still has less than 1,000 miles on it.  My question is this:  Is light engine pinging/knocking when going up hills or accelerating on level ground normal for a new car?  We have started to use high octane fuel (91), but it has not made a bit of difference.  Interesting thing to note is that when we test drove it, the engine light came on at the end of our drive-tech looked at engine and found water in one of the cylinders, supposedly due to the fact that engine had been washed before selling car.  Engine light has not come back on since then though.  Am I worried for nothing?  Thank you.

Answer
Pinging is not normal under any conditions, take it to the dealer, it is under warranty,I'm curious why the engine would have to be washed on a brand new car, something doesn't sound right, take it back to them and tell them to fix it.
If you don't get cooperation from the service department contact the customer service person at the dealer.