My friends and family are all tired of me obsessing about my new car, so I'll run this past you guys as you're the only ones who seem to understand the obsession.
I have a new 07 MCS with 700 miles - Last night after I shut down the engine I was sitting in the car on the phone for a while when I heard a noise - at first I thought it was someone bouncing a basketball nearby. Eventually realized it was the car - when I opened the door I could hear it better - almost sounded like a little backfire... a thwump/bang/pop that seemed to be coming from the undercarriage, not a knock from the the engine compartment. I was still stuck on the phone, so it made further investigation a little difficult. There was also sort of a whirring noise, which I assume is a cooling system?..
Does anyone have any idea what I'm talking about? The car is driving fine - no strange noises other than this, after I shut it down. Do I worry? Do I call MINI? Help?

 

Yeah I get that ,I think it's letting turbo heat out the tail pipe .One cold morning mine was making smoke rings !

 

...i hear the small motor hum as well....could be something like a small oil circulation pump perhaps? maybe for turbo cooling after shutdown?......have to remind myself to pick up a set of factory manuals

 

The whirring/motor hum after shutdown didn't really disturb me... I had that on my last car and understand its some sort of cooling system. It's this popping/burbling thing that freaked me out. I've been saying I wished my R56 had a burble - now I seem to have one after I shut it off!

 

the motor humming is actually an electronic water pump that runs coolant thru the turbo to cool down.

the thumping noise could be the metal exhaust pipes flexing/contracting due to heating/cooling. my s2000 makes loud tikin' noises after the car is shut off and it comes from the exhaust. so a turbo car would make them also since it runs hotter...

 

after my 160 mile comute to work when i shut down the mini it sounds like the exhaust is burping a lil. i figured it was just air gasses venting out after it starts to cool a lil bit. you can hear it coming from the tail pipes.

 

kind of like mini farts . ha.

 

since i have upgraded to a 3'' cat back i really dont hear it anymore.

 

That would be a very realistic and sensible explanation...

except my Cooper does it, too... so no turbo heat there...

It's actually kind of disturbing!

 

I had the same problem on my 2007 MCS. It seems to have gone away after about 500 miles (I have 2500k now). It only happened twice and both times were after a long highway drive. Could it be catalytic converter cooling? trapped heated exhaust air?

 

My car does it as well. Its the DMTL pump (Diagnostic Module Tank Leakage) running. Basically its a small electrical pump that pressurizes (only very slightly, if at all) the fuel tank while monitoring the pump current draw to check the fuel system for leaks, i.e. a loose gas cap. As to why it makes the thumping noise I have no idea myself. I've never heard another BMW Group vehicle with the same system make this noise before. I highly doubt its harmful or detrimental in any way just a unique characteristic of the R56 I guess.

 

I believe it is part of the EPA gas tank vent/recirc system automatically burping its contents after shutdown.

 

I had that thump in my '98 BMW 740i. My mechanic, who is a German car specialist, said he thought it was the exhaust expanding and contracting.

 

It sounds like someone is locked in the trunk on my 2007 MC.

 

I've got the Thump too- so which of us is calling Car Talk?

 

Thanks for this thread. I was wondering what in the heck this sound was. I heard it in the Taco Bell Driveup while i was waiting to pull forward. The car was running though. It also does this at shutdown.

 

This gets my vote. I posted on this a while back. It'll go thump....thump....thump....(repeat N times)...pfffffffffffffffffffft.

One easy way to tell would be to have someone listen for the thump inside and someone else open the gas cap. I've been meaning to do this, but it's way down on my list.

 

Its has to be the gas tank. Here in Oregon we cant fill our own tank...we sit in the car and wait for the attendant to do it. As the tank nears full it makes the same popping/creaking sound. ...

 

my 06 mcs does this a little as well dont think it has to do with the s/c... but mine happens when i first start in the morning

 

I think this is what I've heard on my MC CVT '06 and now on my Clubman MCCa - it sounds like a muffled thump, thump, thump. I've heard it while stopped at a light, after morning start up... and then when I've turned the engine off having driven for a good amount of time. Mentioned it to my SA with the '06 and they never could find anything wrong.

I'd be happy to believe it was just a normal noise - and from this thread it sounds as though it is.

 

Is this what causes the short, electrical pump-sounding noise I hear when I hit the unlock button on my car??

Sounds very similar to how the hydraulic pumps on BMW SMG and Ferrari F1 gearbox cars sound when you open the door.

 

Same here. Mine is 2007 MCS Auto with 4,300 miles.

 

I was told it was a mixture of the exhaust expanding and contracting from heat/cool down and gases forming from these differences in heat...perfectly normal...you can notice it happen at stop lights too sometimes

07 MC (non S) 8600 miles

 

I heard this sound yesterday waiting at stop light. Could not understand where it's coming from. 1,300 miles

 

BINGO!!!! WE HAVE A WINNER!!!!!!!

Exactly!!!! in all honesty...it is ALMOST 99% likely cause.

My Miata tings and burbs a bit after a long run. My Vulcan Nomad does it too.

Also it makes a slight whistle.whinnee. That is the air escaping the gas tank via the venting hole in my gas tank, around my cap. When I insert the key and open whoosh...and noise stops!!! depending on how full the tank is it does it longer or little..also depends on humidity...

Hope that helps anyone else with these noises...

Like eating a bunch of hot dogs and beer at a tailgater weekend NFL party ...your gonna do lot of that too!!!!