1. Timing belt. 10 years or 100K miles? car should be on its 3rd..
2. PCV system. Oil leaks can be worn seals or a clogged PCV
3. Turbo. Any oil consumption? Its possible to remove the intake air tubing to look at the blades and feel for play but if the car drives normal and doesn't seem to blow smoke, I wouldn't bother.
4. Transmission - color / smell of fluid? Black and burnt smell is bad. Brownish black is ok but a change may help.
5. Engine? oil condition, any gunk visible via the filler cap (staining is normal). You could do a compression test looking for consistency. Dry/wet tests will tell you if you have worn rings. You should see about 150 PSI from a warm engine. 125 from a worn engine :-)
6. AWD. Does the car drive right? Does it feel odd when applying power in corners? You'd need a rainy day or snow storm to really check out if the differential is engaging. I believe this model has the haldex which is like FWD until the differential xfers power to the rear so you'd need to try to slip the wheels to test.

 

So this car has about 70k miles on it, relatively on the dot. Just changed the oil, about to change the spark plugs. Wondering if I have to change coil packs with it??? Does it have coil packs?? That aside, should I be purposefully changing out the PCV breather box if it has no issues currently? Any preventative maintenance items I should be looking at replacing? (Also if anyone knows, would my car be affected by the oil consumption issues? It doesn't seem so on the TSB Volvo put out, engine code is B5254T5) Thanks for your guy's time!

 

Why spend the money if you don't have to. The last time that I bought coils, Volvo ones were about $75 each.