Whining sound when accelerating

Hello -

I have a 2008 Toyota Matrix with 56k miles on it. Recently it starting to make a whining sound when accelerating. It’s very subtle, but kinda sounds like a plane taking off. It seems to go away once the car is moving/maintaining speed.

I just got an oil change and the air filter replaced. Also, it seems to idle rougher than it used too, or I could just be paranoid.

Any help would be great.

Thanks

Kate

Does the whining sound chenge with the gear changes? Does it seem to be following the engine speed or the speed of the vehicle? Does it seem to be coming from the tranny, the engine, or the chassis?

And lastly, if you pop the hood and accelerate the engine manually (or have a friend push the gas pedal) can you hear the whining under the hood?

A few thoughts,

Have you opened the hood and to check the oil level and verify the air cleaner was installed correctly? This especially applies for chain shop and quick lube places.

How old is the battery, the alternator on my 2000 Blazer starts whining when it’s overworked trying to recharge a weak battery. The battery voltage should range from 11.9V (fully discharged) to 12.6V (100% charged). I’ve noticed a partially discharged battery (~12.1V 25% charged) causes driveability problems with the Blazer. Most parts stores (Autozone, Advance, etc) will check the battery for free.

How worn is the serpentine belt? A worn out belt can cause all sorts of noises.

Ed B.