I have a new MINI Cooper, about three weeks old. Recently I've noticed that when I start the car up, the engine is cold, and the car is stationary, I get a thumping noise coming from the back of the car. If I sit there a bit it goes away. Other than that the car is fine. No other problems. Does this sound familiar to anyone? Does anyone know what causes it? Any help would be greatly appreciated.

 

My 04 MC does the same thing. I drive about half a mile, then get stuck at al light or something and I get a popping sound coming from the rear of the car. I haven't been able to get the dealership to hear it since I get there nice and warm. I guess I'll have to let them keep it overnight.

 

Thats exactly what happened to me today, as far as the dealership is concerned. I heard the noise as soon as I started the car up this morning. I drove the 12 miles or so to the dealership. They heard nothing. I asked them to to park it for a while and then listen, and they still didn't hear anything. I came back home, parked the car, started it up again a few hours later, after the engine had a chance to cool down, and the noise was there again! So, I will call them tomorrow and arrange to drop the car off so they can keep it overnight and check it in the morning.Then, I'm quite sure they will hear it. I hope so, so that if it's something that needs to be fixed they can take care of it now, and if it's something benign I can know that it is and ignore it! Anyhow thanks for the reply, esallingham.At least now I know I'm not the only one with an invisible critter thrashing about in the boot!

 

Are you sure it isn't the burble of the exhaust? If it's the exhaust, it's supposed to sound that way.

 

My 2004 Cooper S also makes that sound you described. I have not had any problems with the car but that is defininitely a strange sound. I know for sure it is not an exhuast burble. It sounds like something is shaking under the car, but as it warms up it goes away.

 

Same thing happened in my 03/05 and I think my 06 however, I havent noticed or have just got use to it?? It happens in the morning after making my 1st turn. Kinda like something rolling around in the hatch and hitting the side..........the mystery continues.

 

A rhythmic tapping or bumping is sometimes caused by the emissions control system, specifically the canister purge or leak detection pump. The canister purge solenoid is up front, but can sometimes relay sound theough the fuel vapor line under the car. The leak detection pump is under the florr beneath the rear seat on '05 and later cars, and inside the reat fender above the tire on earlier cars. Both of these systems usually run for a short time immediately upon starting the car for the first time then arent heard from for the rest of the day in most cases.

 

My '04 has had the same condition, though i've noticed the thumping/putting is very random, cold days, hot days... It mostly occurs a little while after i start the car when i'm stopped waiting for the green light... @ first i thought the fuel lines where clogged or something to that effect, i would sit there and see how long it lasts for, the car doesn't stall, then i would rev the engine a little and let it settle, then it goes away... i haven't had any problems with it plus being so random i just forget about it...
What Greatbear has pointed out makes the most sense on this situation...
Bluebird, please get back to us with some 411 from the dealer.

MotorOn .

 

My '05 MC does that, and has done it since it was new. No big deal I hope. It always stops after driving about 3 minutes or so

I gave up (or never attepmted) trying to figure it out :impatient

Good thought Greatbear

 

Thanks to everyone for replying. I don't think it's an exhaust burble. If you make a fist, then hit a wall or table lightly, with the side of your hand, that will give you a pretty good idea of the sound. It happens after I start the car, when the engine is cold. Yes, it's not rhythmic at all. A random thumping noise for a bit, then it stops, and I think it has done it while stopped at a light or stop sign shortly after I get under way, but the car is always stationary when it happens. Although I know very little about cars what Greatbear said seems to very possibly be the explanation of the "problem." Since the car is performing beautifully, and I have plans for her during the weekend, I'll take her in to MINI of Towson on Monday, let them give it a listen on Tuesday, and see what they come up with. I have a very strong feeling though that Greatbear is right. In fact I'll probably print it out or write it down and take that info with me. I'll let you all know what I find out. By the way "KiKi" is a 2006 MC-HB/W. Very plain, but love her just the same. Thanks again everyone.

 

My '04 S does it too. I've heard that it has to do with the ABS, and is normal.

 

My '06 MC does it too.

 

Our '06 MCS does this. I just noticed it this morning and was going to post a question!

We back into our garage due to a bad approach angle from the street. I started the car with no music on (rare for me) while I scrounged through CDs. The sound did not start right away--probably after about 30 seconds of running. It made a sort of popping/thumping sound regularly, I'd say about every 7-8 seconds. It sounds like exhaust to me, and it is probably amplified due to backing in to the garage.

Sure enough, it went away as soon as I pulled out of the garage.

No idea . . . .

 

Random knocking and banging when starting the car is usually the exhaust system and the heat shielding under the car expanding. It seems to lessen somewhat over time. When I first got my '03, it was pretty bad. after a few months either I got used to it, or it lessened quite a bit. I would say it's a combination of both of these.

After installing the Milltek, I noticed it making a new 'clinking' sound when heating up, and that mostly subsided after a month or so of thermal cycling. The heat shielding under the car still crunches and pops, but not like it used to be.

One thing seems to be certain, the exhaust system on these cars runs very hot, especially from the catalysts forward.

 

Did you whack a guy and stuff him in the boot?

 

Woulda had to be a rather tiny guy to fold him up and fit in there without putting the seats down.

*Note to self - no abductions in the MINI unless I am driving through Lilliput or get a call from the Lollipop Guild looking for members on the lam.

 

More posibilities! I still tend to think that it might be the emissions control system. It's in no way a metallic sound. More like a thumping, thudding, bumping sound, and I suppose it could be described as regular, if not rhythmic. When I said it wasn't rhythmic I meant that you couldn't use it as a drum track for a recording. Like findude says,it starts about 30 seconds after starting the car then thumps (more or less) regularly(yes every 7 or 8 seconds sounds about right) for a bit then stops. Whatever it is it doesn't seem to be much to worry about but I'll probably still take it by Towson MINI just to be totally sure. I didn't wack a guy and stuff him in the boot either. Thats how I ruined my last car! Just kidding! Thanks again for all the replies.

 

Lollipop Guildmember stowaways! Bwahahahahahahaaaaa!

 

Naw, it's just his trunk monkey.....

http://www.trunkmonkey.com/content/category/4/68/51/

Check out vid #3 & #4

 

I've noticed a similar noise on my '05MCS. I'm almost sure its the exhaust burbble. I only hear it before the engine comes up to temp. and when the car is idling. Its a soft thumping sound that sounds a little like fuel sloshing back and forth in the gas tank right after you've come to a stop. But I've heard it when stationary for a while. so its not a fuel tank noise.

The burbble is pronounced when you are decelerating, but I think it just sort of pops softly when cold and at an idle. The best way to check is to get out of the car and go back there to listen.

 

It's definitely what a poster described earlier about the heat in the exhaust expanding the metal a bit. It's almost similar to the "clicking" you hear when you initially turn off any car, but it just happens to reverberate throughout the exhaust when initially warming up on the Mini. Nothing to worry about.

 

It sounds more like a something lightly thumping the plastic in the back seat, not a metallic sound at all. In fact when I heard it today it almost sounded like it could've been emanating from the rear passenger side speaker.

 

Well, alright then! Perhaps I'll not bother taking it in then. Seems like it's a fairly common thing and a number of people have a very good idea of what causes it. Since there are no real problems with her at all I'll not worry any more about it. Now I have to set aside an afternoon to put my grill badge holder on when I get one! Just kidding, I 'm not quite that lame.

 

On third thought, I'm going to take it in Monday. If I don't that little bit of doubt will drive me crazy. I mean I've already got this problem of making up my mind! Who needs another! Thanks again everyone. I'll let you know what they say.

 

Yes, please let us know!