Not every time, but on every 10th cold start, I get a loud thud which comes from my drivers side door. It seems to happen around 10mph. I thought it was something inside my door rolling around, but it seems to happen at very controlled acceleration. The weirdest part, it switched sides a few weeks ago, and its not on the passenger side. It doesn't seem to coincide w/ my doors locking automatically.. Thats a clicking sound, whereas this is a deep base-like thud. I can almost hear it over music on my HK.

OK... there's more.

When I bought the car, I had it inspected by a reputable imports garage, as well as had a 50k service (tune up.. etc). I felt safe after a good report, and bough the used 2004 MCS at 50k miles. When detailing the car, I found a rat's nest in the boot's tool panel on the left side. I cleaned out a nest of densely packed of hair and chewed insulation to find mildly chewed wires Cleaned it out, taped up any exposed wires and kept an eye out for new signs of life.

Yet even more...

While installing a CAI earlier in the week, I found another nest just behind / below the ECU. Not much chewed on except for the main ECU wire which I taped up. All wires seemed intact, just the rubber coating. No electrical issues to speak of so far... Im hoping these two nests were pretty old.

So, could this be an animal? Should I be worried? What can I do? My car is garaged, and I haven't noticed any new activity, so I think whatever was is there is dead or gone. No smells. Are these two phenomenas related?

 

Mini's do seem to attract mice/rats/squerels...especially cars that are parked for the winter. Our local guy has found them living in the air filter and cabin air filter. If there is no dammage, consider yourself very luckey!! One destroyed wiring harness can set you back hundreads in parts and labor.
As for the thunk...it sounds more mechanical...a scratching sound that will not stop for a period, I'd be worried, but a thunk, sounds like something moving, or shifting, perhaps a suspension part that is binding or something!!

 

Try shutting off the radio to see if it still occurs. My HK system will make a low freq thud after driving off from a fresh start. Always has. I think there is something in the electrical system. The ghost of Lucas most probably.

 

This thud has happened w/out the radio being on, so I can rule out the HK... Though it does sound like a base drum coming out the rear speaker.

I've put my ear to the outside panels and listened for a while.. luckily, no scratching!

 

Its the door locks- 12 mph the doors auto lock along with the gas door. No problems motor on!

 

Well, its usually before or after the door locks. Different sound, click vs thud. Maybe its connected somehow though...

 

LSD ? CV AXLE ?

 

Now you have me thinking..........I've heard the same sound but didn't think anything of it because I keep an umbrella in the passenger door for the wife. I always thought it was the umbrella moving around in the door that made the thud. My symptoms are just as you described........HMMMMMMMM

 

I dont have LSD... Not sure about the CV axle.

Sounds just like a base drum on the HK... very deep thud. I think I'll take out all moving objects for a few weeks. The wierd thing is that it happens when I have a very slow acceleration, so I think I can rule out junk in my trunk

 

Have you tried exorcising your Mini?

I have a dead moth in one of my tail light lens to keep the bad spirits away.

The Chinese use firecrackers during Lunar New Years to do the same.

 

I have the same loud thud since new in my '03 S. Never figured it out, but never had any issues to relate to it. The only explanation I've heard that sounds somewhat rational is that the ABS performs some kind of test. However, it seems like I don't hear it nearly as often anymore (or I'm used to it).

 

Bingo! I have the same thunk with my 04 MCS, and have heard the same ABS explanation.
As far as the rat issue goes, you might try to scare up some "Marten Repellant Spray".
http://www.kwasny.com/index.php?id=202&L=1

Jim

 

Rust on the rotors could be a possibilty. When the brake pads break free they can make a noise.

 

I hear the same thud on the rear passenger side of my car since I've gotten it. Not sure what it is, and it happens only when I drive the car for the first time of the day and it's very uncommon.

 

I heard the same thud it ended up that my rear shocks and springs were replaced end weren't tourqed up to the proper spec..

 

I had a Thus in my 04 Also, removed both door panels, to find a speaker relay laying in the bottom of the door, it would actually sometimes prevent the window from going all the way down. Used some Gorrilla glue and put the relay back on the inside of the door and have not heard a sound since, that was about 9 months ago, no problems with the Window functions either.
On a side note, when I took the car to the dealer for the window not going all the way down they told me it needed a window regulator, 600 plus labor.
So with about 30 minutes of my time and some Gorrilla glue, thud and Window fixed. Cost was about 10 bucks for the glue.

 

My 03' MCS makes the same sound, I am told it has to do with the ABS system reset though I am at a loss as to what moving parts are actually making that noise .....

Nice work and appreciate the heads up on that loose relay. A friend of mine had his dr side window module replaced as it would not fully close. It was an expensive visit to the shop.

To be fair, with regards to your symptoms the dealer's initial diagnosis was correct, as they never actually had your car in and removed the door panel correct ?

 

They actually did have the car in the shop, weather they took the panel off or not I do not know. I know the dealers are in bussiness to make money, but 600 bucks for something that they were really not to sure of is not a good way to do business. IMHO

 

I've had the same exact thing in my car since new. (Took delivery in 11/03) It almost sounds like a pop and if I had to pinpoint it from inside the car it sounds like it is coming from just about the middle of the door opening, between the sill and the seat on the drivers side.

 

sounds like this thud of mine could be just about anything... speakers, shocks, abs, gremlins...

 

Chupacabra