I have a 93 Toyota Corolla DX, Auto transmission, 202,000 miles.
There appears to be a humming noise coming from the front end. It
sounds like a low frequency helicopter blade spinning about - like a
'whomp whomp whomp" sound. If you listen closely, it occurs at all
speeds. It seems to be directly related to the sound of normal
braking, and you can feel it ever so slightly in the steering wheel.
The frequency of the sound increases with road speed, and becomes most
pronounced at 40 - 45 mph...
What I've done to trouble shoot:
1) A slide pin on the driver's side brake caliper was frozen. Caused
brake pad rubbing - replaced pin and relubed the pins. Thought for
sure that was it - however it wasn't.
2) Replaced driver side wheel bearing - as that wheel didn't spin very
well. Didn't change the noise (but wheel turns well.) Passenger side
bearing appears to be fine.
3) Rotated tires. No change.
I'm running out of ideas. The CV joins all look ok - no breakage and
no clicking during turns.
I've only recently obtained this car so I don't know its history - I
don't know if the sound is normal road noise, is typical of the tire
(Michelin) manufacturer, or perhaps a binding caliper...
Any suggestions are greatly appreciated!
On Sun, 24 Sep 2006 22:23:23 -0400, Cathy F. wrote:
I like WWDTM, but haven't listened to it for a while.
Same with Car Talk.
I met Tommy and Ray some time ago when I used to live out near Boston.
They are hilarious.
And their office has a window with gold leaf lettering that says, "Dewey,
Cheetham and Howe".
(Whoa - didn't proofread or spell-check that one!)
I try to catch it every week. Love the sense of humor.
That's cool! It'd be pretty disappointing to find them *not* to be humorous
I know of someone who lives in Boston, whose plumbers are the Trethewey
Bros. (re: Rich Trethewey of "This Old House").
Somehow this doesn't surprise me. ;-) The ironic bit being that I can't
imagine those guys actually cheating anyone... Somewhere I think I read
that only one of them is actually at the garage? (Maybe the other one -
whoever's the elder - is retired, except for doing Car Talk?)
I wonder, if I ever called in, if they could correctly ID me as a Cathy with
a "C"? <g> I'm pretty sure they could diagnose the car problem, as long as
my explanation was clear & complete enough - with the correct accompanying
noise if applicable! OTOH, owning Toyotas - which are 8 years or younger,
hopefully I'd never feel a real need to call in.
I listened to that show when my boss was a guest on the show. A few minutes
listening to these guys did not impress me with their automotive technical
knowledge. They are OK with the stuff that one would learn in high school
automotive shop class, but my boss and I were not impressed with their
knowledge beyond that.
On Sun, 24 Sep 2006 20:11:48 -0400, Cathy F. wrote:
Gee, Cath, when was the last time they gave an ACTUAL answer?!
I used to listen to them when they first started in Boston, and it was a
GREAT show for backyard mechanics. It was live, real time, and you could
call and talk to them and get advice, and not have to leave a message and
hoped they thought your call had enough 'entertainment' value to give you
a call back!
My father-in-law just gave my wife the exact same car with 100,000
fewer miles on it and the exact same problem. In his case the sound
started after some minor front-end damage (minor enough that if we
painted the replacement hood to match the rest of the car, you would
not be able to tell it had happened). I've eliminated the brakes and
the wheel bearings and am, at this point, scratching my head much the
same way you are :) I also checked to see if the wheel well liner was
maybe cracked and dangling onto the wheel - no dice there.
However it did NOT make this noise previously, so it is definitely NOT
normal road noise. Not sure what brand of tires are on it but they are
the old-fashioned zigzag tread pattern, not these newfangled treads
that look like bird footprints.
On Sun, 24 Sep 2006 19:55:20 -0400, SlyckTom wrote:
What I have experienced with this:
1. Shock has gone totally out of oil or gas
2. Tire has a broken belt. This really manifests itself at slower speeds
with a modulation of the steering wheel, that goes away as you speed up.
THIS IS EXTREMELY HAZARDOUS!!! Get this checked!
3. One of your brake calipers has sticking slides, and is heating up the
rotor. This starts out normal, and gets worse the longer you drive.
This is also hazardous.
You can check for sticking brakes by feeling the wheels after driving. If
one wheel is hot and the others relatively cool, that's the problem.
The cause of noises is very difficult to diagnose without hearing the noise.
"Rotational" noises can come from several causes: Sticking caliper slide (I
don't think you freed the slide properly); wheel bearings; tire problem like
a broken belt; brake backing plate touching the rotor; CV joints;
differential bearings; and engine noises.
The caliper bolt (pin) passes through a sleeve in the caliper body. If you
look at the sleeve, there are rubber boots on the inboard and outboard sides
of the caliper between the sleeve and the cast caliper body. You should be
able to push the sleeves in and out of the caliper body, stretching the
boots. The bolt should slide in and out of the sleeves, and the sleeves
should slide in and out of the caliper body. If the sleeves are frozen,
carefully peel back the boots, remove the sleeves (1 sleeve for each
bolt/pin), clean up the OD of the sleeves, and lube with either caliper
grease, wheel bearing grease, or anti-seize.
While you're at it, make sure there are 2 flat metal shims between the back
of the pads and the caliper piston, make sure the anti-rattle clips and/or
springs are place, and make sure the square keys at the ends of the pads are
not loose in the keyway in the caliper bracket. Aftermarket pads sometimes
fit loosely can cause noise, which is why I always recommend OEM pads.
The slide was freed properly. It had frozen in the bore, and I
extracted it with considerable effort. One it was out, I threw it in
the trash and purchased a replacement slide and bolt. I also replaced
the dust boots, cleaned out the slide holes,and greased them with
wheel bearing grease. They now slide properly as you describe and no
longer drag on the disc.
All the tires are fairly new, and I've inspected them for belt
breakage - none is apparent. I also feel the problem would have been
isolated rom rotating the tires.
Granted I have replaced the pads with no-OEM pads (hence no
anti-rattle clips, etc) the rotational noise existed before I replaced
them...so unfortunately that is not the problem.
That leaves us with:
wheel bearings, CV joints; differential bearings; and engine noises.
I can eliminate the engine since it does it whether the engine is
running or not. This also probably eliminates the differential since
that is just a wildly unlikely senario in these vehicles.
So what I'm left with is either:
A binding caliper (worth looking into, but unlikely) CV joints (very
possible, but there's no clicking during turns and the boots are in
good shape), and finally, the passenger side wheel bearing.
I've done some research into the wheel bearing possibility, and that
seems to be the most likely of senarios. But even this I am hesitant
about since the wheel turns fine when its jacked up, and there's no
free play. But from what I've read, this doesnt guarentee a bearing
is in good condition.
Anyway, my next move is to replace the bearing and we'll see from
On Sun, 24 Sep 2006 22:01:43 -0500, "Ray O"
Thank you again Ray. And as a follow-up, I found an empty parking lot
today, and turned the steering wheel all the way left, and spun 360
degrees a few times - very little noise other than the pavement.
I then turned the steering wheel all the way right and spun 360
degrees a few times again - and heard and felt a noise very similar to
the rotational noise as described.
It's now becoming clear(er) that the driver's side bearings are to
blame, since spinning left (the ones I replaced) yielded no
So this weekend I'll replace them, and give an update...unless
impetuousness gets the better of me ;)
On Mon, 25 Sep 2006 13:43:13 -0500, "Ray O"
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.