I'll copy everything and post it on some Volvo forums see what people say there. Not sure any of them have worked on the Diesel versions, but it's worth a shot...
I can already answer your third question. K&N filters are cleaned with their "recharger kit" which includes soap for washing it first and oil to cover it afterwards. It's a very simple process:
- wash with cool water under light pressure stream, water should be flowing from clean to dirty side (easy to tell). Let it sit and dry overnight (no hand drying, no sunlight exposure etc.), the oil comes in a spray can, spray the entire thing to restore the original red color of the filter material (it will be white/grey when washed). Don't overdo it, don't try to make it blood red. Too much oil can potentially destroy your Mass Air Sensor. Reinstall in the car.
This is recommended to be done every 10,000 miles but it depends on how dirty the roads and air are where you live. Last time I washed mine I realized I didn't really need to do it - it probably would have been good for at least another 5,000 miles.
(You can't rewash it infinitely - it is good for 25-30 washed, but at a 10,000 mile interval you can argue that it really is forever).
I'll come back to you on the problems when I hear from other Volvo specialists.
Last edited by _HighVoltage_; June 3rd, 2012 at 12:51 AM.
"It's the difference between watching great sex and having good sex." - Labcoatguy on the difference between an automatic and a manual gearbox.