daverman

I'm now hearing a very faint clunking noise coming from the rear of the car when I'm backing up or moving at very low speeds (<5 mph). It sounds like a marble in a soda can, but kinda muffled.

I think it's coming from the exhaust pipes or mufflers rattling against their supports, but I tried jiggling both pipes and can't reproduce the sound.

I hope it's not the wheel bearings...

Any ideas?

Road Rage

Jack up the car, brake off, spin the wheel. Hear the sound?
Likely wheel bearing. Don't? Not.

Have someone drive under same condition while you listen - determine which side, metal on metal sound, etc.

Not much back there to go wrong. Shock unlikely. Check to see if brake shield is hitting anything.

LarryLynx

How about the "emergency" brake pads?

gohawks63

Check to make sure that one of the exhaust hangers didn't break. It happened in my old Vigor. I'm not sure how many are under there, but there is usually two for each pipe. If one breaks, it allows the pipe to move around more and it could bump against the underbody on occasion. I think I paid $10 for it an took my 5 minutes to replace.

I doubt it's the bearings. Bad bearings don't make a clunking sound. It's more like a loud cyclical hum (i.e. hum-hum) that gets louder with speed and when weight is transferred onto the bad wheel (like going into a curve). I speak from experience here too since my Vigor required the left front wheel bearing replaced at 85K miles.

my2sense

I'm experiencing this same problem also. If you figure out what it is, let me know!

bricot

Did you leave your salesman in the trunk???

Don't have that noise.

daverman

Nah, that would leave a whining noise, not a clunking one

Thanks for all your ideas, fellas. I think I'll have the dealer jack the car up during my next oil change. I bet it's the exhaust hanger. I've had the rubber mount come off of one hanger once.

daverman

OK, I went to Superior Acura. They jacked the car up and asked me to look with the service guy under the car. The whole exhaust assembly was secured and well isolated from the car body... but what's this?

Apparently what has been making the clunking noise was the plastic retainer clip which holds the wire coming from the oxygen sensor in the catalytic converter. It was sitting loosely against the heat shield. Whenever I would hit a bump, the retainer would move in its slot and make a clunking noise against the heat shield.

There's nothing we could do about it. It seems to be a design flaw in the retainer. The gap was too large for the thickness of the heat shield.

I think I'll get the service guys to order a new retainer clip and see if that one has the same problem. In the mean time, if you're curious about what I'm talking about, reach up under your car just behind the front passenger-side wheel, about 1.5' towards the center. You'll feel a lone wire extending down towards the catalytic converter. Tug and jiggle this wire and see if you can get a clunking sound to come out.

my2sense

any updates on the effectiveness of your new retainer clip?

T Ho

A PLASTIC Retainer clip making a metallic sound? Hmmm, I'm not convinced. Then again, dealers aren't often known for their troubleshooting saavy.

Are you sure it's not the brake pads? On my TL-S and my 95 Accord EX, the first time I apply the brakes when backing out of my driveway, I get a distinct clunk-clunk. If I continuing backing and apply the brakes again, no more clunking. Then, I put the car in drive, and hit the brakes lightly after just starting to roll forward again, clunk-clunk. After that, no more. You get it once the first time in reverse, then once the first time going forward. If I had to guess, the steel pad backs are designed with a bit of clearance in the caliper when cold, to allow for expansion as they are heated up during use.

My friend's '01 EX-V6 does it, too. Same exact sound, under the same exact conditions.

I would complain, except that after 7 years and 107K miles, I'm still on the original brakes on the EX. What's to complain about?

Todd

daverman

Surprisingly enough it does. The plastic retainer knocks on the heat shield, and since the heat shield is a large piece of sheet metal, it reverberates and makes the "clunk" noise louder.

I don't know... maybe it is. In any case I still hear the clunks even after a long day's drive.

Road Rage

Acura has had problems over the years with bushings int he trailing arms - they have had several fixes, including plastic shims. I would get some good silicone lube (3M) and shoot all the bushings you can find back there. Also make sure the brake splash shield has not been bent - it is very thin metal and can get out of whack.