Delphi style alternators on some of the engines have a history of alternator bearing failure. Bearing failure will cause a whining noise coming from the engine compartment.Google+
Car Problem Reports
Honda Accord Alternator Bearing May Fail
Honda Accord Problem
Electrical & Lights Affected: 3.0L V6
Average Mileage: 105,333 mi (55,000 mi - 140,000 mi)
Visitor, 2003 Honda Accord, 117,000 mi
Told the alternator and bearing were going out by the service guys at Honda and said it would be a total cost of $661.30 to get the parts and fix it. I brought it in a month before because of a random, whiney, whirring sound. At first it did not make the noise, but they said they were able to recreate the noise and said it was the heat shield, which would have costed $250 to remove and replace. But I did not think that was right so I didn't go for it. A couple days ago the sound got worse and is now a loud, deep, grindy noise that happens everytime I turn the car on, of which they say now it is the bearing and alternator failing.
Be carefull when presure washing your engine.
Visitor, 2003 Honda Accord, 61,000 mi
Alternator whine. Wd40 squirted into the pulley to housing gap silences the noise temporarily
Visitor, 2000 Honda Accord, 135,000 mi
loud whirring noise from engine compartment
One day the alternator started whining, and stopped charging at the same time. It needed replacement and the manufacturer agreed to pay for parts even though it was out of warranty. I paid labor, which at the Honda Dealer, was over 200.00.