I have oil in the spark plugs wells on my 2006 Volvo XC90 -2.5-Turbo and I've cleaned all the oil, even on top, under the cover, it had oil.
Has anyone else happen to have this same problem??

 

not that uncommon - a few possible causes 1) oil spilled while filling 2) the seal on the oil filler cap is old 3) your PCV is clogged and is pushing some oil out of the filler cap seal 4) there's a tube that runs up to the top of the cam cover that may be leaking. This tube typically gets replaced when doing a PCV job.

So next step is to check your PCV system - try the latex glove test (see vids on Youtube)