I have smoke coming out of my exhaust when I accelerate or rev the engine. It also happens on start up but if the car is left idling it goes alway. Any help is appreciated.

 

What color is the smoke, and what does it smell like? For example is it whiteish blue with a burned plastic smell, white with a sort of sweet smell, black like a diesel?

If it's the bluish acrid smelling smoke, you're burning oil and that could be from your turbo, a valve seal, worn piston rings, etc. The first thing I would check in this case is the turbo. If this is the problem, then the startup smoke might be caused by oil left in the exhaust from the last time you drove it getting burned off when you start it up.

If it's white sweet smelling smoke, then it's probably coolant. The most common reason for this is a bad head gasket. If this was the issue, I would usually expect there to be a bit of white smoke all of the time vs. only on acceleration.

I don't know what would be causing meaningful black smoke in a Mini. Especially absent any other symptoms.

How is the car performing?

 

Was performing well until something new went wrong. I just made a new post about it. My mechanic ended up saying it was more then likely my valve stem seals were bad and that getting the oil change loosened stuff up and made it start smoking more.
“He didn’t use the term stuff but I don’t remember what he said.”
He did say for me to wait until I would eventually replace my timing chain and to do them at the same time.