Accord 98 EX V6 Engine & Reverse Noise Mysteries

I have over 85 K miles on my 98 V6 sedan. A few weeks ago it started
making two noises -- don't know if they are related.

Driving forward, the engine makes a mechanical noise that sounds to me
like scissors opening and closing; sharpening a chef's knife against a
sharpening rod; a steam radiator valve letting off steam
intermittently; or someone shushing, shhh, shhh, shhh. The noise
stops at idle and seems to pick up in rhythm as I drive faster.

Related or not? I hear a high pitched "eeeeeeeeeee" sound when I go
into reverse. Can't pinpoint the location.

Thanks.

 

Sounds like the brakes as opposed to the engine. If you rev the engine
while in Park and not moving does it happen? If it only happens with motion
I would rule the engine out.

Lots of cars do that.

 

Seth4/5/08 9:11pUKJj.344339$

Small rocks trapped between the rotor and the sheet metal splash shield on
the disk brakes will make this sound. The noise is different when backing up
than going forward. Noise stops when you stop and changes frequency as you
drive faster. One day it will just go away when the rock wears off enough to
fall out. Sometimes the built in wear indicators on Hondas make a similar
noise. Pull your tires and check the pads if you are concerned.
--
Pickleman

Please remove "yourpants" to reply
1998 Civic HX MT with 142K
2000 CRV EX MT with 98K

 

Thanks for all replies, it is most likely brake related. Friend just
told me he has heard my brakes and thought I knew about it. Unless
the sound of the brake wear indicator has changed between my first two
sets or my hearing is shot, I don't hear that characteristic screech
on (forward) braking, so I like the rock theory.

I just gunned the engine in park and didn't notice the noise at all --
the problem is motion related.

I did notice something interesting: the engine sputters at 4,500 RPM
and doesn't go beyond that, like 1-1,500 RPM short of red line. Did
an engine governor kick in or do I have yet another problem with the
car?

 

If the noise increases and decreases in direct relation to car speed, it's
almost certainly brake related.

You're in the DC area it appears. Don't know how much rain/snow you get in
winter, so the following may not apply.

A common source of the noise you describe is rust on the perimeter of the
rotor. This builds up, eventually contacting the slide shims on the pad
mount bracket. The contact is not uniform, so you get a chk-chk-chk sort of
noise. To see if this is the case, you need to pull the pads and shims off,
and look for bright scuff marks on the shims.

See here for a photo of that, almost all the way down at the bottom of that
page.
<http://www.tegger.com/hondafaq/rustybrakes/moredetail/brakes2_detail.html>

 

-----------------------

The computer in some cars won't let you go anywhere near redline unless
the car is in a gear. Your Accord may be that way. Same reason you're
never supposed to go WOT with a chainsaw unless it's in wood.

'Curly'

 

Can you name a single car that is like that?

WTF difference does it make wether or not the engine is under load?
Valve float doesn't care.

 

2000 civic with A/T will not exceed 4500rpm unless in gear.

t

 

eh? mine did. are you sure the timing belt hadn't slipped?

the only vehicle i know to have a deliberately low rev limit in
different circumstances is a ferrari when being driven with the valet key.

 

jim beam4/8/08 23:

In my experience this behavior is sometimes mimicked by an ignition
breakdown at high rpms. Most of the Hondas that I saw it appear were
Preludes for some reason. Usually traced to something simple like spark plug
gaps getting too big or bad plug/coil wires or breakdown of internal
insulation in the coil or valve adjustment. It sometimes FEELS like a fuel
delivery problem. Check all the simple stuff first.

Once had a gentleman bring in an accord that would start when cold but then
die out when warm and would not restart until cold again. He had spent $1500
dollars trying to fix it at a local garage and finally brought it to the
dealership. A quick call to Honda's TechLine indicated that there had been a
batch of distributor rotors with a injection mold defect that allowed spark
shorting to the distributor shaft. The hole that the spark traveled through
was smaller than a hair when warm and absent when cold. The fix was a part
that cost less than $5.00. He only brought it in when his previous mechanic
told him that the car needed a new ECU for $600 (this was in the 80's).
STF-Simple things first. The bad rotor looked perfect. A new rotor fixed
the problem 100%.
--
Pickleman

Please remove "yourpants" to reply
1998 Civic HX MT with 142K
2000 CRV EX MT with 98K

 

One of my passengers isolated the sound to the left rear wheel. I
checked the sheet metal splash guard? that hugs the inside of the
brake rotor and did find any objects. I checked it by pulling in or
out on it and listening and feeling for blockage or objects.

That noise that the wheel makes when reverse sounds like violin string
vibration more than the vague 'eeeeeeeeeee' I described earlier.

What's odd is the asymmetry of the sound, if indeed it is coming from
the same wheel in both directions. Why a rustling or scraping sound
when moving forward and a violin string vibration should moving
backward, if rocks or rust? And why doesn't the friction just scrape
away the whatever by now?

Maybe it is the brake pad or something with brake caliper. I'll have
to bring it into the shop when I get a chance.

(I would take the wheel apart myself to inspect but I have the
facility or torque wrench to put the tire back properly.)

 

Check the very bottom of the splash guard and see if it's rubbing against
the rotor. Over time they get rusty and begin contacting the rotor at the
bottom.

And you still need to check the pad mounting shims as I described before.