Grinding noise when decelerating?

Maintenance/Repairs
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1

I have a 2001 Honda Accord (automatic) with 128k miles.

I’ve been having some strange grinding noises coming from the front while driving. It started off a couple of weeks ago as a very low (only some people could even hear it) humming kind of noise. It suddenly got worse one weekend and has now evolved into a louder, clearer grinding sound. Thought it was a wheel bearing, but the shop says it isn’t. They think it might be the transmission (ugh). I’m not auto savvy at all so I’m turning to you guys for some help. Any idea what the problem may be? Here are some more details and a youtube video of the sound below:

  • When accelerating, you can hear a low rhythmic humming, if anything.
  • When coasting (not accelerating or braking), especially at speeds below 30 MPH, it makes a much clearer grinding noise that is still very rhythmic.
  • When accelerating or braking, the sound goes away or is much lower and less noticeable.
  • Appears to be speed dependent and not based on RPM.
  • The noise is present when shifting into neutral while moving but not in park or reverse.

Here’s a video of the sound: http://www.youtube.com/watch?v=y78bPvcrJrY. It’s filmed with my phone so it isn’t great but you can probably hear it using headphones at a relatively loud volume. You can hear the low thumping/humming a little before 10 seconds in. You can hear the grinding noise from :11 seconds until the end (I’m decelerating), with it most audible after :20.

Any theories? Thanks in advance!

2

Sorry, I tried…but I can’t hear much there. Is it possible to put the phone closer to the noise source (or where you think it may be coming from)? Maybe on the floor or something. You may want to have someone else hold it down there for you so you can pay attention to the driving.

3

I couldn’t access the audio at all. Unavailable.

You describe no noise in no load conditions There is a pump in the transmission that makes grinding noise when going and under load conditions. From researching your issue. I do not know if it is replaceable but I’m sure a honda tranny specialist could tell you same. (Honda’s haven’t had a great name in transmission issues)

4

I couldn’t hear much on that but something like this often points to a problem with an exhaust heat shield.
It’s actually a rattle but due to the frequency it often comes across as a grinding noise.

A heat shield rattle can be erratic in nature and may even come and go. It can even be caused by a microscopic crack so small that one may have a very diffcult time even seeing it. Generally these can be fixed without too much trouble.