Noisy noisy car.
November 16, 2011 6:28 AM   Subscribe

What is the noise my car is making? I think it might be tire.

At about 40mph / 50kph, my car starts to make a droning noise, increasing in loudness all the way to highway speed. It sounds like it is coming from the front left of the car.
When I put in the clutch, the noise remains, so it is not engine. The wheel bearings were changed last year and so were CV joints. Front tires were also changed about 8 months ago, but noise only arrived a month back. There is no wobble or vibrations at all.
posted by Frasermoo to Travel & Transportation (12 answers total)
 
Any chance you could swap the tires left-right, and see if that changes things?
posted by notsnot at 6:38 AM on November 16, 2011


if the break fully unlatched from the rotor? Maybe its sticking?
posted by amazingstill at 6:41 AM on November 16, 2011


That is unlikely to be sticking brakes.

It could be tires - although a noise of that magnitude would suggest something visibly wrong - inspect the sidewall and all around the tyre for signs of something in the tread or irregularities (ie bulges). The fact that there is no accompanying vibration makes this less likely to me.

You don't tell us what car you have, which would be more than a little helpful. If it is front wheel (your comment about CV's suggests it is or it is 4wd) drive your transmission may well be on the front left of the car and would make this kind of noise (diff output bearings for instance), but without knowing the make and model this is speculation.

The lack of vibration suggests transmission to me. Swapping the tyres left to right is relatively easy and will eliminate that variable. Be aware that where noises come from from one seat may change as it resonates through the body. Have you travelled in both front seats and reached a consensus on the location?
posted by Brockles at 6:54 AM on November 16, 2011


It sounds from your description very much like a tire. Simple test, as notsnot indicates, is to rotate the tires. Look in your owner's manual to see if you should swap L-R, F-B or diagonally.

If the sound moves, it's time for tires. Also, the penny test may be useful -- take a US penny, put it in the groove with Lincoln's head pointed at the groove. If you can see the top of Lincoln's head, your tire is worn out.

If it doesn't, then maybe it's a bum CV joint (yes, they were changed -- but if the boot broke open and dirt got in, it might be trashed,) bearing, brake caliper sticking (that's usually a higher pitched noise) or transmission/transaxle, depending on where it's actually located in your car.

Wheel Noise is partly in Click and Clack's Class A (If you ignore it, it will cost you lots of money) problem, but mostly in Class C (If you ignore it, it may kill you.)

(On Preview) Brockels makes a good point that whine without vibration is often transmission. Step one is check fluids, step two is check for leaks. Step three is to force a shift change. With an manual, change gears when it's making the noise, does it change? With an auto, it's harder -- you need to set it to the highest gear you can without being in drive (that'll be 2 on a three speed, 3 on a four, etc.) and then when the noise is happening, shift into drive which should upshift the transmission.

On a CVT, if you have an "S" or "L" mode, put it in that, get to speed, then shift to regular drive, which should change the ratio.
posted by eriko at 7:01 AM on November 16, 2011


Response by poster: mazda 626 v6 manual transmision. fwd
posted by Frasermoo at 7:03 AM on November 16, 2011


The wheel bearings were changed last year and so were CV joints.

I know you said this (above), but it really sounds like a wheel bearing; however, my most recent wheel bearing experience included droning at 40mph and shaking violently at 70mph.

Wheel issues can be dangerous. Have a mechanic check it out yesterday.
posted by TinWhistle at 7:38 AM on November 16, 2011


another vote for wheel bearing, and the rear bearings can go bad also. Cv joints click when you go around corners and starting shaking in corners as they get worse, I have never had one 'drone'. A bad bearing goes whuuwhuuuwhuuwhuu or something similair. This includes bearings in the transmission and differential as well as well bearings. And just because you changed it last year doesn't mean you didn't get a bad one, get a bad install or damaged a seal. Definately rotate tires as that is cheap, easy and eliminates one potential source. If that makes no change you need to get it on a lift and have a mechanic start checking stuff out.
posted by bartonlong at 10:38 AM on November 16, 2011


Does the sound vary depending on acceleration/deceleration? If it is a wheel bearing, they'll make more noise when weight is transferred onto them. Let off the gas at speed, or make a hard right turn.

You may also want to look for something caught in the wheel/brake area. Once chased down a noise that was a piece of styrofoam lodged in the brake caliper bracket and was rubbing against the brake disc. Almost made a 'playing card in bicycle spokes' type noise with the way it was being struck by the vent ribs in the middle of the disc.
posted by narcoleptic at 12:55 PM on November 16, 2011


Cupped tire or aftermarket CV axle is my guess.
posted by PSB at 5:51 AM on November 17, 2011


Response by poster: looks like wheel alignment is out.
posted by Frasermoo at 7:45 AM on November 17, 2011


Best answer: Wheel alignment will not cause that noise unless it has created tyre damage as a consequence.
posted by Brockles at 8:52 AM on November 17, 2011


Response by poster: correct. there was tyre damage.
posted by Frasermoo at 6:44 AM on November 24, 2011


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