I have a 97 850 128K miles LPT that smokes(blue) when I first start and also after ideling for about 4-5 minutes. I also am noticing some smoke from the oil dip stick at idle.
There are many opinions about the possible causes of blue smoke so I would like some ways to diagnose it to the root cause. I also cleaned the PTC valve this week end by taking it out and cleaning the smallest opening and made sure u could blow air throgh it without any resistance. I spoke with my trusted mechanic(not Volvo or Euro car guy) and he thinks it could be the turbo or head(valves, seal ,piston ETC.) He states that at this mileage leak down tests are often incorrect. I always thought the LPT's were almost failure proof on the 850's ? Maybe some idea on cost and a place to source a rebuilt head and/ or a turbo would be apreciated. Do you also know how many hours a mechanic would take for the PCV change ? I am fairly handy with tools but I don't want to spend my whole weekend on it. If anyone knows of a affordable Volvo tech in Portland, Oregon I would apreciate it.

much thanks for all the responses