[Coolbeanzrider]

There's a humming/whining noise when stepping on gas pedal and immediately stops when letting off the gas. The sound is loudest around the front passenger area. Someone recorded a video with the same exact sound that I'm hearing. They never posted about whether they found what was wrong or not.

 

[scratchfury]

Does it make that noise when the A/C is off?

 

[Coolbeanzrider]

It makes the noise both when the ac is off or on. Even when the heater is on. The sound only happens when stepping on the gas pedal.

 

[t-rd]

You need to take the serpentine belt off and check the idler and tensioner pulleys, most likely one of those.

 

[Coolbeanzrider]

I took the serpentine belt off and all the pulleys are moving smoothly and no noise. Except the water pump. Its making a scrapping/dragging sound when I turn it.

 

[KW2004Accord]

V6 or I4 - replace the water pump, now or if you have a timing belt replacement (for the V6) coming up. It may not be the problem but if the W.P. goes out you could overheat the engine & blow a head gasket.

 

[Coolbeanzrider]

It's a I4 engine. Definitely going to let the car sit until I can get a new pump. Car was driving smoothly until the cold weather started. Thanks for the help guys.

 

[nate704]

Many 4 cylinder auto cars have the same issue.My father in law has 2003 I4 auto that makes the exactly same noise above 65 mph (both accelerating and cruising) on highways.
Transmission whine. I have searched all over the place, but no feasible fix except tranny rebuild or replace the parts within the transmission = $$$$$

 

[accord04ex]

It's a I4 engine. Definitely going to let the car sit until I can get a new pump. Car was driving smoothly until the cold weather started. Thanks for the help guys.

Interesting, please update when you can!

 

[nickandre]

It looks like the sound varies without RPM changes -- idle pulleys and water pump will be rotating at the same speed regardless of accelerator. I think the fact that it only happens when you apply power suggests transmission noise, unfortunately. That's the place where you're applying stress when the throttle is opened up.

 

[Coolbeanzrider]

Hey guys I'm back. Things got pretty interesting this past week, initially the water pump pulley was not spinning smoothy and there was a grinding sound when turning the pulley.

I replaced the water pump then drove the car the around for a bit and everything seemed fine. No humming noise when driving or stepping on the gas pedal. But at lower speeds, 30-45 mph the humming sound came back. I checked the pulleys all over again and the alternator pulley started making a low grinding noise even though it turns smoothly. You can't really tell its grinding until you spin continuously and that's when you hear it.

Took the alternator in to advance auto parts and the bearings were wearing out. Waiting on a replacement alternator to come in. Will update soon.

 

[nickandre]

Hey guys I'm back. Things got pretty interesting this past week, initially the water pump pulley was not spinning smoothy and there was a grinding sound when turning the pulley.

I replaced the water pump then drove the car the around for a bit and everything seemed fine. No humming noise when driving or stepping on the gas pedal. But at lower speeds, 30-45 mph the humming sound came back. I checked the pulleys all over again and the alternator pulley started making a low grinding noise even though it turns smoothly. You can't really tell its grinding until you spin continuously and that's when you hear it.

Took the alternator in to advance auto parts and the bearings were wearing out. Waiting on a replacement alternator to come in. Will update soon.

Thanks for the update! Some of these can be tricky to track down.

I wonder why the alternator pitch would change with accelerator pedal position? Doesn't sound like there would be more or less torque on the belt when that happens. I guess one way to rule out the transmission would be to idle up the engine in neutral to see if the problem recurs.

 

[qman]

Thanks for the update. It may have been my post that you read. I never did figure it out. I have the exact same high pitched whine that kicks in around 65 mph and only occurs when I'm accelerating. It goes off when I let off on the gas. I assumed it was some sort of air leak whistle. Never thought it might be a pulley somewhere. I have a rebuilt alternator so if the pulley on mine has any grinding feeling to it I'm gonna swap it. Keep us updated on this one.

 

[Coolbeanzrider]

The alternator has been swapped out and so far the noise seems to have really gone down. There's still a humming noise when I step on the gas pedal but there's way less noise now and quickly disappears. Hopefully whatever was wrong was fixed. I'm going on a long trip tomorrow and update about any noise I hear.

In case people are wondering the noise can't be reproduced when the car is in idle. I even had a friend rev the car in idle while I stood listening to the engine. Sitting in the car and revving the engine I can't hear the humming either.

 

[Coolbeanzrider]

Update: 284 miles later the humming sound gone down significantly and its extremely pleasant to drive once again. There's a small humming sound but that's always been there and so far its way better than before.

 

[Suzuki4x4Automatic]

Very similar whining noise with your vehicle that I'm having currently. Mine appears when applying gas as well. Did it go away by itself or was it the alternator replacement? Thank you in advance!