Honda Odyssey makes loud whining noise at highway speeds

I have a 2005 Honda Odyssey with over 100k miles. Recently, it has started making a loud whining noise (it reminds me of the sound my old manual transmission sedan would make when I was in second gear but
needed to switch into third) when we drive at highway speeds (55 mph or more) for more than 20 minutes or so. The sound continues at lower speed and even when we go into park. It doesn’t stop until we turn off the engine, but the next time we drive the sound doesn’t start until we’ve been driving at high speeds for a while. It also intensifies when we make sharp turns. I took it to my mechanic who
thought it was simply the fan coming on because our coolant was low, but we refilled that and it hasn’t made a difference. Also the temp gauge doesn’t show that or car is overheating. Any ideas? Thanks!

Based on the fact that it is an 05 Odyssey with 100K on the odo, and your description of the symptoms, I’d guess your automatic transmission is making that noise. Transmissions have been an Odyssey problem for quite some time.

Get ready for a transmission rebuild at a cost of about $3000. Sorry.

It could be a number of things, but I would take the car to a good transmission shop (not a chain like AAMCO) first. Honda transmissions don’t take abuse to kindly, and I assume you did not buy the vehicle new. Hondas also should have the fluid drained and refilled very 30,000 mile or so, even though the manual may not say so.,

How many miles on the car and do you have a maintenance history for it?

Does it whine if you rev it while not moving?

I had an alternator make a whining sound once as it died. A friend said it sounded like a spaceship landing. I ordered a new alternator on Thursday hoping to replace it on Saturday. The old one breathed its last breath on Friday, 20 miles from home on the way to work, forcing me go straight to the nearest shop to get it changed. The new one was on my doorstep when I got home from work. I stuck it in my inventory in my garage where it still resides.

I suggest that you check the fluid level in your transmission.

Have you opened the hood and gave a listen. Could be a belt, accessory or tensioner.

Thanks everyone! I really appreciate your help.

A bad power steering pump can also make a whining sound.

Another idea, when you drive on the freeway for a while, the engine accessory rubber belts can heat up and that causes them to shrink, putting more force on the associated bearings and idler pulleys and the belt itself.