I have a 03 Cooper with 30,000 miles on it. I have a rumbling noise coming from the rear end. It sounds like a muffled noise, almost a vibration, as if a ball were inside a can, vibrating (muffled). It is noticeable at slow speeds even over smooth roads. It has been checked by Mini dealer. They acknowledge the noise, but could not find or fix it. Any ideas?

 

Are your tires in balance? Alignment checked? Might want to see if that makes any difference....just an idea

 

Everything is fine. Just this annoying rumble noise. Anyone have any other ideas?

 

Checked out the bearings on the car? Could cause this to happen sometimes.....anybody else got any ideas????
Those are the only things I could think of off the top of my head...

 

If there are no vibrations associated with the noise, it may be a loose muffler baffle.

 

rear section of the heat sheild, or the battery shield

 

Need more information since it's difficult to diagnose using the written word:

Does the noise vary in intensity, frequency, or loudness? If so, does it vary in time with engine speed, engine load, road speed/load, or while turning left or right at low or high speeds or low or high G loads (hard or gentle turns)?

Is this a high pitched noise, or a low rumble? You said "...as if a ball were inside a can, vibrating (muffled)...". How large a can (not trying to be smart alecky here). Does the ball sound like it's bouncing inside the can (shaking spray paint), or rolling around inside the can (ball bearings in a doffee can, being swirled? If so, does this bounce change frequency/pitch or intensity with engine speed, load, road speed, or any variables noted above?

If the sound doesn't vary relative to any variable but remains relatively constant: electric fuel pump, rear washer pump, electrical relay buzz.

If the sound varies relative pitch/frequency to road speed, changing in intensity depending on whether you're turning right or left, and how hard you're turning: bad wheel bearing, cupped or worn tires, possible dragging brake. You can rotate tires or change to another set to check tires (borrowed, or put your summer tires on if you've got snows). Generally if the noise gets more intense in a curve, you're due for wheel bearings.


If the sound varies relative to road speed but NOT relative to side loading: dragging brake, cupped or worn tires. You can rotate tires or change to another set, also gently apply - not hard - and release the parking brake while moving to check brakes.

If the sound varies relative to engine speed or load and NOT as relative to road speed: Loose baffle in exhaust, bad exhaust, bad cat, loose heat shield, or some other random loose "thing" that gets excited at a certain frequency. Find thing, tighten.

Hope this helps!

 

Does the noise vary in intensity, volume, pitch? If so, does the variance occur with vehicle speed or engine speed? If engine speed, maybe an exhaust leak after the resonator or around the muffler cans? If varies with vehicle speed, then a wheel problem. Try rotating fronts to rears and see if any change?

 

Thanks for the info, but you guys are thinking way too much. like I said the car is in mint condition. None of these issues exist. The sound is a rattle, but muffled. Sounds like a ball in a can bouncing only the sound is muffled. Something sprung or under tension perhaps. BMW/ mini checked it out and could not find the noise. It is in the rear the brakes are great the exhaust is great. It can be heard under the slightest bump. Has nothing to do with speed. The rear latch replaced. I don't think it is the spare housing. What else. Any ideas?

 

To be very specific the sound is like a rubber ball in a large coffee can. When you hit a bump and it doesn't have to be a big bump, it kind of vibrates, with the sound I described. That ball bouncing spring loaded sound. This is in the rear end of the car.

 

Sounds like someone stuck a rubber ball in your pipe?

 

Take the privacy shelf out of the back and see if it still occurs.

 

You're not gonna fall for the banana in the tailpipe trick?

Is there a tennis ball in the boot?

Some things just can't be explained. My 2000 Tahoe....for whatever reason....every now and again just to check my sanity.....the rear of the interior would make a "weeeeeeeeeeeeeeeeeeeeeeeeeeeeeee" noise for about 12 seconds.....then stop. Wouldn't hear again until you did. 2 Dealers and many friends heard it.....but each of them....:c onfused:

Have you had someone ride in the back to try to "feel" the noise? Can it be felt by you?

 

AH! BINGO! You know what it is I bet!!!! It's that fancy little rubber ball at the end of the rope that holds the shelf up! One or both are swinging and hitting the side of the boot! Virtual $5! Who's on?

 

I was thinking the same thing!

Now that we have the description...

 

 

It has to be that......I tested it myself. It sounds EXACTLY like a tennis ball in a BIG coffee can. Cuz I play with coffee cans and tennis *****.....too. Yeah.

 

Also see if there's anything rattlin' around in the spare tire well or battery well (MC or MCS). If it's an MC, I don't know how the spare is secured (mines an MCS with no spare) but I've had other cars where the spare, being an inflated, bouncy squeaky "thing", can certainly make some strange noises if not secured from bouncing/moving. Strapping it down and adding a rag or two always cured it.

Please DO let us know what it was! Well, unless you've inadvertently left something truly humiliating in your boot... in which case we want pictures!

 

 

you might want to check the heat shielding around the muffler, and the body panels directly above the muffler.

 

I asked the husband to help me swing my ***** around tonight! Never knew I had *****... but he showed me where they were. Has the OP figured out this mystery yet? Maybe one of his ***** fell off and is rolling around somewhere?

 

You always want to make sure your "*****" are properly secured with the OEM equipment. Failure to do so could result in an inadvertent collision of the left and right "ball" and will prove catastrophic! Mods to these parts should be avoided at all costs.

 

Thanks for the tip! My ***** seem to be far enough apart and swing freely enough so as not to be catastrophic. No "Big Bang" here! OMG! It's 27F out... I think the cold is getting to me. Do you think the OP already knew the answer and was just quizzing everyone?

BTW- I was a hockey cheerleader when I was in high school! Our team sucked but I still liked hockey.

 

If it's cold, does the noise stop because the ***** are held more tightly in place due to shrinkage? Oh, never mind...

Well? We're waiting! What was the noise????

 

You are aware of the "Gorgeous Girls in Minis" thread right?!?! Sucky team or not.....a hot cheerleader in a Mini would be the perfect addition to the post. ....waiting.......waiting......waiting......