Koko4

I have a '97 Civic LX with 216,000 miles on it. A month ago the harmonic balancer worked itself loose, snapped / loosened all three drive belts, and destroyed the woodruff key. Got towed to Honda - new harmonic balancer, new woodruff key, new bolt - everything has been fine since. I estimate that I've put 1,500 miles on the car since this issue.

Today I was driving and I heard a grinding-like noise - I was going about 40mph. It sounded like it was coming from the vicinity of the harmonic balancer, so my first thought was CRAP. It's backed off / bad again. Weird thing was when I hit the brakes, the grinding got noticeably louder. Tested my "theory" a few times, applied the brakes on and off a few times and confirmed that while I was hitting the brakes, the noise increased.

Then it stopped. No more grinding, no more noise at all. And just to clarify, it's NOT the noise associated with bad brakes / worn rotors. It definitely sounded more pulley-like.

The reason I am asking here is because of the weird association with the brakes being applied and the noise increasing. I drove the car another 30+ miles since this has happened with no recurrence of the noise, at all. And obviously when I tried to Google "grinding noise that increases when brakes are applied" I got rotors, rotors, rotors.

JarvisW

Hmm. maybe you got a rock in the pads and it worked loose?

If you are really concerned, maybe have the Dealer check it over since they are the last ones to touch it?

Check all your belts for wear too. Also, might have been Alt/AC/PS pump bearing/s starting to go out.

TomCat39

I remember that. You were traveling for work so didn't have a whole lot of choice and thats why you had the dealer fix her up.

The thought I had was something caught in between the pads and rotor and either disintegrated away or dislodged.

See if you see any scoring on your front rotors, likely driver side by the way you described hearing the sound.

And for piece of mind I would also check the pulley to see the bolt is still tight etc.

The other thought is if say the alternator bearing/bushings are just starting to go, they may intermittently make a grinding sound until it's bad enough to be constant. This would also apply to Power Steering pump and I think the AC compressor can be the same but not sure there.

Koko4

Thank you guys for the suggestions. I heard the noise again today (drove about 60 miles, and only heard it for < 1 min out of those 60 miles). I was going about 75-80mph and had my girlfriend in the car. She mentioned that it sounded like it was coming from the "center" of the car (head unit area). Put my head down that way, and she's right.

So this is more than likely clutch / transmission related, rather than accessory belt or pulley-related. I changed my clutch 20,000 miles ago with an Exedy clutch (my old clutch had a spring break - the clutch itself still had plenty of life left on it).

I greased the TOB, splines, etc as instructed, and had the flywheel resurfaced when I did it. Everything is torqued down and I used blue Loctite on the flywheel bolts.

With that being said, when I was hearing the noise I did a test by pressing in the clutch and putting the car in neutral. This stopped the noise, and when I went back into gear the noise was not present. I should have done one or the other (press in clutch OR put in neutral) to effectively pinpoint which action stopped the noise.

Is this likely a TOB issue, or something more sinister such as an input shaft bearing or something of the like? The bearing that is pressed into the flywheel was also replaced with the Exedy kit. I have a feeling the source of this will be hard to pinpoint, because it only happens intermittently like this. When I had the transmission out, I remember spinning the input shaft by hand and do not remember any noticeable slop or play in it (I just had a buddy who's transmission input shaft bearing went bad, and we were able to wiggle his around a good bit - he was experiencing loud grinding only upon deceleration in gear, though, so this is likely not that).

JarvisW

Usually the TOB isn't engaged until you hit the pedal. So, It may be in the trans.

Pull/check clutch install apart, and if you spot a bad installation, then actually GREAT!, fix whatever it was. If it all looks normal... Get a trans :/

Also, this ***-U-MEs you have proper play and pedal height for the clutch. Its not keeping it engaged that is..

TomCat39

You know, I had a screaming grinding sound after replacing my clutch with the exedy kit. I would shut the motor off and start it up and it would be gone.

It did this intermittantly for a couple of months and not very often. It stopped and has never done it again and I've been driving on this clutch abusing the snot out of it for a couple of years now.

Yours may not be the same thing. But then again it might.

I personally think the throw out bearing on the exedy kit is questionable but wears into place okay.

The throw out bearing is spring loaded and the slave piston keeps it riding lightly on the pressure plate fingers. It can make noise until it gets fully loaded by pressing the clutch pedal is my theory.

If your grinding progressively gets worse and longer, then worry.

For now I would think just drive it or you will drive yourself to drink trying to "fix" a phantom noise.

This is basically what I've learned with my Honda over the years. Paranoia will cause you to spend needless money and worry about **** that ain't broke or at least not broke yet.

These cars are tough and can work until they are fully broke.

Koko4

This is probably the best advice I've heard. You're right that the car is "old" - 217k, and will make odd noises every now and then. Occasionally it may strand me. I need to just make sure the oil / coolant stays topped off (also having an unrelated problem where I'm losing enough coolant to cause an overheat every 2-3 months...) and I also need to realize that this sound could very well go away.

I'm lucky because I'm not having any pop-outs, grinding, etc. I generally am not an aggressive / crazy driver and don't abuse my cars. The weird thing, though, is that this never happened until the other day, and I've put around 20k miles on the clutch since I changed it. No slipping, either. All good things!!

Koko4

So I've got an update to this post. I am fairly confident that it is the front driver's side brakes / caliper sticking. The noise happened today, and changed resonance as I slowed down. I was in third gear when it happened - engaged the clutch and the sound was still there. Put it in neutral with the clutch disengaged, sound is still there. Put it in 2nd gear - sound still there. So I attempted to slow down and isolate the noise, and sure enough it changed tone and quit when I stopped. Didn't reoccur on the drive home.

Could this be a sticking caliper, or is it more than likely the wheel bearing going bad? I will lift the car tomorrow and do the 12-6 test (12-6 is wheel bearing, and 10-2 is tie rods, right?). I will also try greasing up the slide points on the calipers.

Is there any possibility that this could be caused by the master cylinder? I checked the fluid and it is full. There are no clunks, loss of braking power, or jitters (warped rotor feeling) to speak of.

JarvisW

Prob not the master, as it goes through the proportioning valve. It would do both sides then.

But you can get a rebuild kit for the caliper and the other ones too, might as well do them all or risk them locking up at 75mph :/ They aren't much, even at Honda.

Then clean the pistons and cylinders thoroughly. might be rusted inside too. If its too bad, you have to replace the whole thing. Do one side at a time in case you need to reference it. (if your bleed nipples are toast get them too)

Then bleed farthest to closest to the MC.

Good luck!

Koko4

Tested the wheel bearing by shaking the wheel - no issue there (thank God). I then got to looking at the pads. Inner pad on driver's side was worn down ALMOST to the metal. There's the source of my scraping! I think the caliper was sticking, so I replaced it. Didn't want to fool with trying to free a stuck pin / clean it up / play the waiting game, so I dropped the $50 on the replacement caliper. All should be well now. Thanks for the input and help, as always. And I'm happy to say - Issue resolved!!

JarvisW

If one sticks, the rest will too tho.

Plan on replacing or rebuilding the rest SOON. Like I said, not good to have one decide to lock up at 70+mph

Glad its working for now tho!

TomCat39

Glad you isolated and resolved your issue. Glad it was an easy fix of brakes and not a tranny drop, that's a lot more work.

Cheers.