Metallic Knocking Noise at Rear??

[niqui]

hi,
yesteday night my car starting making a pretty loud metallic knocking noise at low speeds, not at idle, from about 2kmh to 20 or so...it kinda sounds like you are hitting an empty coke can...loud metallic knocking and "tinkling." it seems to be coming from the rear, i think drivers side.
i went for a hard drive yesterday all day, but i had no issues?

[endofanera7]

Originally Posted by niqui

hi,
yesteday night my car starting making a pretty loud metallic knocking noise at low speeds, not at idle, from about 2kmh to 20 or so...it kinda sounds like you are hitting an empty coke can...loud metallic knocking and "tinkling." it seems to be coming from the rear, i think drivers side.
i went for a hard drive yesterday all day, but i had no issues?

I think all the 6MT ///M cars make that noise. Especially when kicking in the clutch while make a turn or going over a small bump. The noise is associated with the rear differential as explained in various threads.

A quick search will bring you to all those discussion threads in a beat!

[niqui]

Originally Posted by endofanera7

I think all the 6MT ///M cars make that noise. Especially when kicking in the clutch while make a turn or going over a small bump. The noise is associated with the rear differential as explained in various threads.

A quick search will bring you to all those discussion threads in a beat!

i have done 8300 km on this car and have never heard it, it doesnt sound healthy at all, and it is pretty loud.
the car kinda always had a light mechanical tick sometimes, but nothing like this
it doesnt happen when turning particularly if at all.
when i start or roll out of the drive-way or a stop sign, its knocking around....

[GAM3OVR85]

Originally Posted by endofanera7

I think all the 6MT ///M cars make that noise. Especially when kicking in the clutch while make a turn or going over a small bump. The noise is associated with the rear differential as explained in various threads.

A quick search will bring you to all those discussion threads in a beat!

Endo, sup bro

[GAM3OVR85]

Originally Posted by niqui

i have done 8300 km on this car and have never heard it, it doesnt sound healthy at all, and it is pretty loud.
the car kinda always had a light mechanical tick sometimes, but nothing like this
it doesnt happen when turning particularly if at all.
when i start or roll out of the drive-way or a stop sign, its knocking around....

Sorry to hear Niqui.
So this happened after our drive? Best bet is take it to the dealer tomorrow morning if you are not busy!

GL bro

[nvez]

http://www.m3post.com/forums/showthread.php?t=144569

Check out that thread.

[niqui]

im already going to the dlr tomorrow morning around 11am for some work so i will add this, its just confused as to what it is and driving it and all that...
thks

[ISAR]

Originally Posted by niqui

hi,
yesteday night my car starting making a pretty loud metallic knocking noise at low speeds, not at idle, from about 2kmh to 20 or so...it kinda sounds like you are hitting an empty coke can...loud metallic knocking and "tinkling." it seems to be coming from the rear, i think drivers side.
i went for a hard drive yesterday all day, but i had no issues?

Did you look underneath to see if someone tied an empty coke can to your car? I mean, it is possible.

[Green///Hell]

Mine makes a weird mettalic knocking noise when the car is turned off once I park
It sounds like its coming from the front tho, now I'm worried

[niqui]

Originally Posted by ISAR

Did you look underneath to see if someone tied an empty coke can to your car? I mean, it is possible.

first thing i did...
i will send it tomorrow...weird.

[endofanera7]

Originally Posted by MTL Bimmer

Endo, sup bro

Hey wassup!

[12:03]

says the guy that money shifted the other day

ohnoes

its slow enough that you can hear the bent valves now?

[Greg P]

Originally Posted by niqui

hi,
yesteday night my car starting making a pretty loud metallic knocking noise at low speeds, not at idle, from about 2kmh to 20 or so...it kinda sounds like you are hitting an empty coke can...loud metallic knocking and "tinkling." it seems to be coming from the rear, i think drivers side.
i went for a hard drive yesterday all day, but i had no issues?

This is really spooky but my car started doing exactly the same thing the other day. Have only noticed it twice at low speeds around 5-10 mph. The empty coke can is exactly what it sounds like - I'd be interested to find out if you find anything . I've looked under the car and can see nothing.

[niqui]

Originally Posted by Greg P

This is really spooky but my car started doing exactly the same thing the other day. Have only noticed it twice at low speeds around 5-10 mph. The empty coke can is exactly what it sounds like - I'd be interested to find out if you find anything . I've looked under the car and can see nothing.

if you gas hard it disappears, but low in 1st gear or reverse or even second it is fully there. it is not the differential, nor the bushings. i told service about it, he said i know its thr bushings, i said no, take it for a drive with me. he took it and said he has no idea, they have to check and its the first time theyve every heard that. perhaps fuel tank, something is lose, or the exhaust canister, those were one guys ideas. a matter of tightening i hope

[Greg P]

Originally Posted by niqui

if you gas hard it disappears, but low in 1st gear or reverse or even second it is fully there. it is not the differential, nor the bushings. i told service about it, he said i know its thr bushings, i said no, take it for a drive with me. he took it and said he has no idea, they have to check and its the first time theyve every heard that. perhaps fuel tank, something is lose, or the exhaust canister, those were one guys ideas. a matter of tightening i hope

Let me know when you get a resoliution (I'll let you know if I find something too). Sounds like exactly the same thing I'm getting, notice it most when driving around car parks in second. Once I'm on the main road it's gone ... until the next time.

[Race_Doc11]

I had the noise once ...there was a thread for it
http://www.m3post.com/forums/showthr...ird+noise+back

[niqui]

Originally Posted by racedoc11

I had the noise once ...there was a thread for it
http://www.m3post.com/forums/showthr...ird+noise+back

was it a rock in the end...

[Race_Doc11]

I think it was a rock got stuck between the rotor and the shield. I remember driving on a stripped paved road the night before that happened to me

[Reedomn]

Originally Posted by racedoc11

I think it was a rock got stuck between the rotor and the shield. I remember driving on a stripped paved road the night before that happened to me

It has happened to me 4 separate times. It is definitely a small rock caught between the brake caliper and the black aluminum shield behind it. It will go away. Also, this is different from the lower thumping rotational noise the differential makes from the back right wheel on slow right turns. I had that too. Dealer replaced differential fluid and all's well...

[MaximumPwr]

Mine did this for a day and a half day. Sounded very metallic like something was stuck in the spokes of a bicycle. I even got under the back of the car(sound was coming from the rear) with a flash light to see if a wire coat hanger or some kind of road debri was stuck up under there or something. Didn't see anything. Didn't even think to check the brakes. Never thought a rock would be stuck in there. But it was exactly how you guys are describing. Forward or reverse, rolling slow, clutch in or out, in gear out of gear. PING! PING PA-PING! Then the next day.....nothing. I even made an appointment at the dealer, but canceled because it went away. So you think it was really a rock in the brakes?

[Kdawgm3]

Had same problem. At slow speed (5 mph) could here a loud metalic pinging sound coming from the left rear wheel. As the wheel rpms sped up, the sound would disappear. I guess the rock would get pinned by the centrifugal force of the rotating wheel. I was unable to see any foreign object and had planned to remove the wheel. Before I got around to this, the sound disappeared.

[J08M3]

Originally Posted by racedoc11

I think it was a rock got stuck between the rotor and the shield. I remember driving on a stripped paved road the night before that happened to me

yep, this has be discussed in a number of threads. It's happened to me numerous times and then goes away for a long time. I have a pebble driveway so I'm sure that causes the stone to get there most of the time.