3

I have a 2005 Honda CRV (RD7), with 190k km on the clock. Over the last 10000km or so, there's been a slight hum coming (I'm pretty sure) from the rear, and sloooowly getting worse.

The specifics of the noise:

  • It starts getting noticeable around 60km/h
  • It peaks in volume around 70km/h
  • It seems to get slightly attenuated from around 80km/h onwards
  • It is worse when I have load in the rear (1-2 passengers)
  • It's a really loud hum, filling the cabin, but with no specific rhythm to it
  • I can't say for sure that it gets worse or better in turns

Some background:

  • About 20k km ago, I put a new set of Pirelli P7s on the rear. At the time, I wasn't aware that my rear suspension was in need of some work, and the tires accordingly feathered.
  • I replaced the rear shocks about 7000km ago, but the damage to the tires had already been done.
  • I have checked all the other recommended sources of noise, including flushing both the transmission and rear diff - this does not seem to have materially improved the noise.
  • I've had the car for almost 3 years, and do an equal mix of city and highway driving.
  • I'm in Brisbane, so salty air could be a concern. To the best of my knowledge though, the car has never done any beach driving.
  • Also to the best of my knowledge, the car has never done any serious towing (or carried big loads), or gone proper offroading.

In summary, I can't for sure pinpoint the noise source to bearings (usual tests like spinning, tugging, cornering have inconclusive results). I also can't get any consistent idea of how long a set of bearings on the CRV should last. The tires are definitely feathered (probably about 1-2mm ridges), but I have no idea how much noise they would contribute with all else being equal.

Based on a LOT of other posts on the net, service center and mechanic opinions on this particular issue isn't always accurate, and unfortunately I don't have the money ($500/bearing installed, $150-200/tire) to throw at the problem and hope for the best.

Any advice would be greatly appreciated!

PS - I am probably skilled enough to install the bearings myself, but they're still $150 a side, and apparently on this particular model there's an issue with getting ABS sensors out of the hub without breaking them, which will add another $50-100 per side potentially.

UPDATE

Ok, I've rotated the tires front to back, and also tested with the spare in the place of the heavily feathered tires in the back. I found:

  • There is a slight reduction in overall noise, but it is not completely gone. Whether this is because there might still be a different problem, or whether it is because the feathered tires are now generating noise at the front, but resonating through the cabin, I don't know.
  • With the slightly reduced noise, I tried the swerving slowly at about 60km/h trick. The noise seems to dissipate slightly when I veer right, and stays about the same when I veer left. For reference, this is a right-hand drive vehicle.
  • The pitch changes slightly between about 60 and 80km/h, after which it drops in volume to about 100km/h, making it difficult to detect.
  • At 100km/h, it becomes 'rhythmic' - basically coming and going at probably 1Hz or so.

UPDATE 2

Just did some more reading on tire wear patterns. It seems that the guys at the shop describing the issue to me, had their terminology wrong. What I have, is heel/toe wear, NOT feathering. It is also not related to my (previously) worn suspension, since that would likely cause diagonal wear.

Would this cause road noise as well?

  • Have you tried moving the rear tires to the front and see if the noise moves with the change? – mikes Aug 25 '14 at 10:28
  • Not yet. The front tires were on the back for a short period before I rotated them, so they're sliiiightly feathered. I'm first going to try and swap out my spare for one of the rears, and see if there's a change. – roelofs Aug 25 '14 at 10:32
  • Does the hum change in pitch/tone with different speeds? If you have a "tin ear", ask someone with known musical ability to listen. Tire noise will almost always change radically in pitch/tone with road speed. – TDHofstetter Aug 25 '14 at 12:30
  • @TDHofstetter - I've added some comments above. It does change in pitch, however, I'd imagine bearing noise would do this too, since it's rotation speed changes? – roelofs Aug 25 '14 at 14:06
  • @roelofs, bearing noise is likely to change in pitch but other things (loose exhaust, suspension, body rumble, etc) probably will not. I'm trying to rule out other possibilities. – TDHofstetter Aug 25 '14 at 14:11
0

If you find slight scalloping around the outer edges of the worn tires, that's the most probable source of your noise.

  • The car is in for a service this morning. The tech seems to think on initial inspection that there are definitely two sources of noise, one of which is a bearing. I will take it to the tire place, and the Honda dealership as well, and report back on findings. – roelofs Aug 25 '14 at 23:07
0

i had the same issue ended up changing the wheel bearing and was able to remove the ABS sensor but after re-installed the sensor gave out and the ABS light came on. ended up spending extra $120 for a new sensor. good luck ..update the other wheel bearing started making the noise 2 years later. time to repeat the process

0

So, this is a slightly delayed answer, but the problem turned out to be the bearing. Immediately after having it replaced, the noise was SUBSTANTIALLY reduced, and I could actually hear the other rear bearing also starting to fail (albeit very faintly).

With the low noise, I'm able to hear some slight tire noise as well as described above, but pitch and volume is nowhere near that of the failing bearing.

Rule of thumb here appears to be, if the noise is overpowering (drowns conversation, high pitch at speed), it's probably a bearing.

As another poster pointed out, the ABS sensors do present a problem - I ended up having Honda do the whole thing for about A$470 (and they even cleaned my car ;-) ). Compared to some other issues I've had, this is actually a reasonable price to pay.

Thanks again for all the advice!

Kind regards,

0

The best thing to do is put the car on a hoist and run it using a stethoscope to find the noise. If there is no noise then it could be the tires. There is also a centre bearing on the driveshaft to listen to. BTW to change wheel bearings the ABS sensor can stay in the hub. All you have to do is unplug it and be careful not to break it when pressing the bearing out and in, and besides the 10 mm bolt will likely break when removing it.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.