I recently replaced the timing belt, balancer belt, water pump, and drive belts on my 2002 2.3L VTEC. Now during idle, I hear a whirring sound. It's not horrible but concerning. The drive belts are tight. I was confident I installed the timing and balancer belts correctly and plenty tight. Any ideas what's causing the new noise at idle and is it worth worrying about? TIA.

 

"Usually" that sound after a t-belt replacement is a sign the t-belts are too tight.

You can run the car with the acces belts off (alt, ac, ect) since the wp is driven by the t-belt....so to test remove them, run the car and see if the sound is coming from under the cover.

 

Timing belt isn't supposed to be TIGHT like an alternator belt.

Remove the upper timing cover.
Take the long span of the timing belt (towards the front of the engine). You should be able to twist it just about 90 degrees with your fingers.

Having said that, it's not unusual for a new belt to make a little bit of whirring noise until it polishes itself up by running. And it'll stretch a little bit in the first couple weeks.