We have a 2004 Honda Odyssey that is due to go in for 90,ooo mile service and was told it would be over $1100 because the water pump needs to be changes at this interval. Can you tell me why this is necessary?

Replacing the water pump is insurance against it going out. A new timing belt will be put on to an old water pump. The water pump is needed the $1100 bill is not needed. Check other dealers and see what the price is.

Yout engine has a rubber timing bely that keeps the pistons and valves synchronized. If it breaks your engine will be scrapmetal and need to be replaced. A pump and timing belt should cost around 850. It is less labor to replace the water pump at the same time or you could wait untill the pump fails and spend 5 or 600 on the pump alone. Your mechanic should be including spark plugs and wires, fan belt and filters at your quoted price. Ask your neighbors who is a good mechanic.

Timing should be replaced only at recommended mileage interval. Please do no look at the years. If your cars mileage is low then you do not need to change the timing belt. It is completely scam and Honda is trying to avoid the lawsuits and trying to give business to their dealers. I was told that the timing belt change is way overdue since my van is 10 year even though it has only 82,000 miles. I got the timing belt, water pump and tensioner replaced and paid $895 to the dealer. I asked them to keep the old parts for me and when i looked at the old parts they looked like they still have 80% life left. I got mad at me that I fell in this scam and spent unnecessary money and got original parts out. Please go by mileage and do not change the timing belt until it is 130k miles.

Rubber ages, so 10 years is probably not too soon. Honda says 105,000 mi, and it is new engine if it breaks, so I wouldn't go to 130,000. One thing I have changed on every car I have ever had is the water pump. Easy to change at the same time, not so easy, later. (It is driven by the timing belt.)