This issue has been happening for the last several years.... probably at least 3-5 years. It seems to only be an issue during cold weather months.

Car: 2006 Mini Cooper (Non S), Automatic (CVT). I live in the Chicago suburbs.

Issue: Engine is started from cold. Temperature gauge is buried at cold measurement. Engine starts fine on the first attempt, and idles fine when in neutral. Placing the car in drive, there is a noticeable "clunk" of the transmission engaging. This does not occur when going into reverse. When the transmission is shifted to drive, the engine stumbles and RPM's drop and recover erratically. In some cases, the service engine light will briefly come on, most often it does not. After a few seconds, I will start driving, still with engine at cold temperature. The low speed control is very poor, and the car surges and runs very rough. If I need to stop before the engine begins to come up to temperature, the idle will drop substantially low and the car will stumble and struggle to keep running. I sometimes have to shift to neutral and give it gas to keep from stalling. Once the engine has been running for a few minutes, and the temperature reaches ~1/3 to 1/2 of normal operating temp, these issues seem to magically go away. The car has always had crappy speed regulation and surging at idle of low RPM, but I think this was more of crap programming for the CVT/computer.

Stuff I've done without improvement: New air filter/intake (DDM works "CAI"), New fuel filter, new ignition coil, new plug wires, new plugs. Battery is new-ish (maybe a few years old). All of these have been done at different points, and usually for unrelated reasons, but the issue has never been resolved.

Stuff I have not done, but may be a culprit: Fuel pump? Injectors? Transmission fluid change? computer reprogram? Winter gas? Alternator?

Looking for some input / explanations as to what can be done. I'm not looking to dump tons of money into this car, as it is simply not worth the money right now. It is my commuter car between my house and the train station. It leaks, has rust, burns oil, and is generally just a depressing money pit. Let me know your thoughts.

 

I would get the codes read next.

 

 

dito, till then I'd let the engine warm up a bit before driving and see if that helps.