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View Full Version : OT What causes this tire noise??



winchman
03-05-2008, 05:06 AM
I do a lot of walking, and I often hear cars making a sound like rrrrrRRRRRmph rrrrRRRRmph rrrrRRRRmph as they go down the road. It starts out low, steadily gets louder, and abruptly restarts with a slightly different tone at the loudest point.

I've heard it from many different sorts front-wheel and rear-wheel drive cars and light trucks. I'm sure it's tire noise, but I can't figure out what's amiss to cause it. My best guess is that the alignment is way off, and the tires are scrubbing with more and more sideways pressure until they slip and the cycle starts over.

Roger

Your Old Dog
03-05-2008, 05:26 AM
Sounds like repetive pattern in the highway to me. I assume you're familiar with the doplar effect and that's not what you're talking about.

winchman
03-05-2008, 08:43 AM
I doubt it's the road, since it happens almost everywhere I walk with a variety of vehicles. Most don't make the sound, but there's enough that do to make me curious about what's causing it.

Doppler makes it change pitch as it goes by, but the pattern remains the same.
Roger

Dragons_fire
03-05-2008, 09:56 AM
different tread patterns hitting the road cause the noise. most road tires now are designed to cancel out the noise. bigger offroad tires and cheap tires will make more noise than better designed tires.

winchman
03-05-2008, 10:41 AM
It's definitely not the road noise associated with offroad, mud, or other "aggressive" tires. I see vehicles with those all the time. The noise they make is usually steady.

The tires and vehicles in question here look like everyday street tries that you'd expect to see on your regular Taurus, Oldsmobile, Chrysler, Caprice, or Crown Vic, or just about any other kind of normal everyday car on the street. The sound isn't nearly as loud as that of the average Jeep or truck with offroad tires, but it's definitely more than the normal traffic noise on city and residential streets.

Roger

stuntrunt
03-05-2008, 11:34 AM
Doppler...

Runt

Wirecutter
03-05-2008, 11:46 AM
This thread reminds me of CarTalk, where people call in and try to replicate the noise their car makes. Click and Clack grade the performance, then try to figure out the problem.

I had some cheap tires that learned to make noise. When they were new, they had great grip, and the rate of wear was good. But the way they wore out was different. With normal tires, you can look at the tread to determine when to replace them. These tires (Techna brand, late '80s vintage) started getting noisey. They would also wear out of balance.

(I thought they were out of balance from the way they felt while driving. I checked for lost weights on the wheels - they were all still there. Got them re-balanced. Problem went away. Problem returned after a couple thousand miles. No missing weights again.)

When they seemed to need balancing a third time, I got rid of them and replaced them "name brand" tires. It was then that I realized that the car was much quieter on the road. The noise had snuck up on me over time, and I had thought it was just the car getting old. Someone suggested that the tires got loud as the internal structure of the tire began to degrade. If that was the case, I'm just glad I didn't drive them all the way to failure.

And that was my education on cheap tires, i.e., you get what you pay for.

-Mark

ptjw7uk
03-05-2008, 11:56 AM
A lot of the noise you hear is the noise from the tread pattern which also depends on the type of road surface.
In the UK they 20 - 30 years ago they began to try out all concrete road surfaces but the road noise they generated caused so many drivers to stop and examine their cars that the authorities had to erect noitices to warn drivers of the increased road noise.
We also have sections of road that have a new type of surface that has reduced road noise where the main road passes very close to houses.

Peter

dfw5914
03-05-2008, 12:01 PM
You guessed right Rodger, the cyclic tire noise is due to poor alignment. Toe in or toe out, the tire side wall flexes until the limits of traction are reached, the tire then slips sideways and the cycle repeats. This will cause a scalloped wear pattern on one side of the tread contact area of the misaligned wheel.

Your Old Dog
03-05-2008, 01:20 PM
You anywhere near Area 51?

RPease
03-05-2008, 01:34 PM
My hearing must be getting bad........I can't figure out what....


......... rrrrrRRRRRmph rrrrRRRRmph rrrrRRRRmph

.........sounds like...........:D

darryl
03-05-2008, 01:49 PM
I believe you guessed right. A friend of mine had a similar problem, and it turned out to be a combination of worn tires and misalignment. There was some motion going on with the suspension bushings as well, so that had it being a combination that was hard to nail down. It wasn't a simple repetitive noise, it was compounded by the suspension components moving sideways in the bushings. This wasn't nailed down until the car was sold and the subsequent owner had it checked out by a different mechanic. Kind of a sad case as my friend wouldn't have sold the car if she had known what was really going on with it. Not a major repair- tires, suspension bushing package, and alignment.

ahidley
03-05-2008, 02:34 PM
Its caused by NOT rotating the tires. they become cupped. They will make all kinds of noise. ITs especially troublesome on the rear tires of front wheel drive cars.

Carld
03-05-2008, 02:51 PM
It could be from tread seperation or twisted tread. If the tire gets a bubble on the tread from seperation or the tread gets what looks like an S curve in it that can cause noise as the tire rolls at speed.

kendall
03-05-2008, 04:18 PM
A small car with a heavy driver will also cause odd tire noises.

Best alignments are done with the car loaded exactly as it is when driving, see a lot of people who totally clean out their car remove tools etc, get it aligned, then load it up with all their stuff again and end up with a car that's totaly out of alignment.

Another thing that will produce odd noises is having tires with different pressures, the noise doesn't actually change, but you get beat cancellations and amplification which tend to produce a cyclic sound.

Semi related: There's a drive through near my house that has a large maybe 4ft diameter drain in the drive through lane, not sure how deep it is looks to be about 6ft to the water.
If Istop just exactly right over that drain, and let it idle I get an extremely loud cyclic 'whoom whoom whoom' sound that has people walking out of the shops accross division ave (main drag) looking around to see what's causing it. The sound cycles at about 1/3rd idle RPM, (800rpm) is pretty much directionless, and can be felt in your chest and teeth and the mustang itself isn't loud.

Ken