Ever since I started learning to work on my car — about a year ago — all of my friends and family want me to work on theirs. No surprise there, and I'm happy to do it. Trouble is, my diagnostic skills aren't really up to snuff yet, so often, I have trouble tracking down the actual problem. Such is the case here with my friend's '96 Accord, unfortunately.

It's sort of a wobbly vibration sound. It almost sounds like a warped rotor, but I don't really feel anything in the steering wheel, and it doesn't happen when we step on the brakes.

The sound only happens sporadically. It either only happens when it rains, or it's far easier to trigger in the rain, at least. The most reliable way to trigger it is to drive really fast, and then let off of the gas and let the car coast. When it was happening tonight, it would stop (or greatly reduce) if I gave it the slightest bit of throttle; not really enough to cause significant weight transfer, just enough that the car wasn't actively slowing down, if that makes sense. Sometimes you can hear a hint of it during normal driving, but it gets pretty severe when you speed up then let off the gas, but often, it doesn't happen at all, no matter what you do. Oh, sometimes there's also a very quiet growling sort of noise when you accelerate or decelerate — even in dry weather — which may or may not be related to all of this.

Initially, she and I were certain it was coming from the front-left corner of the car, but earlier today, a friend was riding with her and he thought it was coming from the rear-left corner, and after riding with me, she thought it may be coming from the rear-left as well, but she wasn't sure.

I tried reseating both wheels on the left side tonight, thinking/hoping one was just loose and wobbling, but that didn't seem to help any. A buddy and I thought maybe something in the suspension was loose, but it all looked okay to me (but again, I'm sort of a noob). I put both of the left corners up on jack stands and used my floor jack to compress the suspension, but I didn't hear any unusual sounds, and everything appeared to move as it should.

Now, she bought the car a couple of months ago, and shortly after she got it, her crank pulley came loose. I pulled it off and the little notch that locks it to the crank shaft seemed like it'd been banged out wider than it should be, but I wasn't really sure what a pristine one even looked like, so I just bolted it back in with a borrowed 200 lb-ft electric impact gun and a rented pulley tool and hoped for the best. A week or two later, it came loose again, so I ordered a pulley tool from Amazon and a new pulley bolt from the dealer, and put it on using a 4-way. (I didn't have a torque wrench at the time.) That seems to be holding, but that notch definitely seems to be wider than it should now, so we put a new pulley on the wish list, which has since arrived, but I haven't had time to actually install it yet. (Yes, I have a torque wrench now too.)

Update: After a lot of head-scratching, I'd sent her home, and she just texted me and said, "Well, I got it to make the noise in every gear and every speed possible." I asked if she was still triggering it by releasing the throttle, and she said, "No, I was maintaining a constant speed. Happened randomly. I got it to stop by pressing in the clutch and just letting it coast briefly. Seems to be worse around curves and RPM seems to have some sort of effect but idk what." But when I was driving it tonight, disengaging the clutch seemed to have no effect, and when I was driving it the other night, it started happening and I put in the clutch and pulled over and the sound continued until the car came to a halt. I revved the engine a bit while doing this, and I didn't notice any change in the sound.

So, any ideas as to what may be causing this? I plan to replace the crank pulley tomorrow, but I'm not optimistic about it solving this particular problem.

 

If it was the crank pulley the sound would not change from loaction to location on the car.

Now wheel bearings on the other hand can induce all sorts of funky weird sounds that can resonate the whole cabin of the car.

Jack up the left front wheel, securely, off the ground. Start the car and put it in gear, listen for wheel bearing sounds. Do this again with the right front wheel. Listen for sounds, noises, vibrations etc.

On the rear wheels raise them up and pull on the wheels in the 9 & 3 O clock and again the 12 & 6 positions. Spin the wheels and make sure they freewheel smoothly. Any rough stiff movement may be indicative of a worn bearing.

Being a chicks car, remove all loose junk from the car. And make sure the spare tire/jack/tools are stowed properly. Loose trunk junk can make a hell of a racket.

 

I would also check the differential, I had problems on my 95 with a noise and vibration caused by low/worn out fluid.