Ok i know this problem has been going on for a while now but here it goes. We bought a used 03 mini s. It has almost 50,000 miles on it and it was running good for a month or so. than all the sudden my wife was driving it home one night and it cut out on her on the road she had to push it out of the road than it started just fine and she went home. than it did it again we were leaving a place and it cut out again in the middle of traffic. we pushed it again and than it wouldnt start again. so we got it towed to the dealer and it worked just fine after that. it would studder when we be driving it on the road the light inside the car would turn on than i would pump the gas and it finally came back. its been a on going problem since we got the car and now were stuck with it. we took it to bmw and they couldnt find nothing it wouldnt do nothing for them they said they changed the ingnition and updated the computer program and the car worked fine for us after that but i didnt think they did anthing. so we were driving on a 3 hour trip and in the middle of the highway it cuts out again the light turns on and its like the car goes dead all the lights turn on and the car is not responding to the gas than all the sudden it comes back online like nothing happen. now the car doesnt even start. its been sitting at my house for a couple of weeks now just dead we change the battery cause it went dead it started than cut out 30 sec later than would start again.

Does anybody know of anything that will help me. Let me know. Thanks

 

Is the SES(service engine soon) light on? Was the dealer able to get any codes? Are there any codes now?

I've heard of some of the early cars having a bad engine harness.

 

sounds like a hassle but check the ground bus on the passenger side up by the headlight . it'll be the plug with all the brown wires going to it . it's said this gets corroded . look for a greenish colored growth . clean as necessary . then check your obvious ecu connections etc . all the relays and boxes for possible water infiltration . make sure you disconnect the battery negative before the above . especially the ecu . don't want any spikes .

 

cage26, have your battery load tested at an auto parts store first. You have to start somewhere and if you start with a know good component you can eliminate that part.
While your back there check all connections in the battery box including that orange thing that must have a capacitor in it so wait a while before messing with it after the battery is disconnected.

 

I agree with norm03s...you may have a dead cell which is shorting out when heated. Might end up being a fairly cheap and easy fix...I'll cross my fingers for you.

 

I agree with Herbie Hind, you seem to have an intermittant open circuit. When you say that when this happens, it won't start... do you mean.

1 It won't crank

2 It cranks but the engine never starts

When this happens, what do the dash lights do?

What do the headlights do (key on, headlights on)

Start looking for loose connections, harnesses, abraided wires, bad grounds, just like Herbie said.

The next time it won't start, have someone depress the clutch, and turn the key to the start position. Now being very careful not to get run over, or get your hands in a bad place, start jiggling every wire and connector you can find, including the wires at the battery

(MC or MCS) Stick or Auto?

If you are lucky, you will jiggle something and it will start, then start a closer investgation. Pull connectors apart and put them back together. Shake and pull, sooner or later you may find the problem.

If you do have a bad connection, then you might be able to make it quit while it is running by doing the same thing... just be very careful not to get burned, run over or some other nasty thing. I'm talking about doing this in your driveway, not going down the road. hehe

good luck

YD