My 07 XC70 is my first car with turbo charged, my questions:
How to check if the turbo ran properly?
How to mainternant to keep it in good working condition?
Does it need any lubricate? How to lube it?
Thanks

 

The turbo is a closed system that oil and coolant runs through, you cannot check it in any simple way short of removing it. If you treat it well it should not fail. I just got my car out of the shop for a failed turbo. Here is what I've learned from this.
Turbo rules:

1. ALWAYS Change oil at suggested intervals. Check your oil frequently and learn your levels and recognize when it becomes dirty or contaminated. (Especially for older/higher mileage turbo.)
2. Allow car to warm up at least a minute so that heated oil is running through the turbo. Allow it to idle for a minute before shutting it off. I use this time to check my mirrors, set GPS, radio, gather my personal items.
3. Avoid extended high exhaust / high RPM driving. It is fun to push the turbo when you need it, but pushing it too hard too often can lead to a failure.

I bought my 02 XC70 used, so I assume the previous owner was not following some of these rules. Others may know more than me, but this is what I've learned from my experience.

 

+1. Its also a good idea to visually check periodically for things like oil spotting on the driveway or weeping around the back of the engine. Not uncommon for the turbo's oil return line seal to fail - which is messy but not a big repair. Other parts of these cars will benefit from regular oil changes like the variable valve timing systems which are driven by oil pressure. For that reason I'd also recommend a move to synthetic oil if your car isn't already running on it.

 

The turbo has a high pressure oil line from the rear passenger side of the block (facing the engine) to the top of the turbo housing. From there, the oil pressurizes the bearings and the remaining low pressure oil drains back into the back of the engine block where the seal that the other poster mentions. I agree to keep an eye on any oil leaks as they are easy to fix on this model.

The most important part is, as mentioned above, oil changes. I've had cars that have had perfectly good turbos but the oil pan was full of junk. I've cleaned the oil pans and hit the resume button and kept going.