BMW Repair: smoke coming from tale pipe, leak down test, oil consumption

Question
I've checked the fluid levels and everything seems to be alright.The oil level was low, but the seller said that she just did an oil change.
Could it be an oil leak?If so, what would that have to do with smoke coming from the pipes?

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Followup To

Question -
I just purchased a 1997 328i BMW,and there is smoke coming from the tale pipe. I've noticed that smoke comes from the pipe  when the a/c is on. I just wanted to know is that a a/c problem or could that be a serious motor problem?

Savoya

Answer -
Check your fluid levels oil,coolant and does it use excessive fuel?If any are badly low there is a problem do investigate.

Answer
If the oil was just channged it should not be needing any oil.If it was an oil leak you would see spots on the ground.All you say you see is smoke,you should have an oil consumption test done.While having that done a compression test and cylinder leak down test.These will tell you where the oil and smoke is coming from.