I just joined the board. Had Volvos before and just repurchased an 86 760 wagon. My question regards a strange happening with the turbo on this car. When I bought it the previous owner had the smoke out the back and front seal leaking problem. I replaced the flame trap and pvc system and smoke and leak gone. Also I noticed that the play in the inlet compressor of turbo was not too bad, (better than I had hoped for). So I drove the car for a couple of weeks and noticed this- The turbo was way nosier than my 84 760 water cooled one. By nosier I mean turbo whine. And on a cold morning I pulled out and hit the gas and I know the impeller must have been hitting the housing, loud noise from turbo. So I babied the car and found that when it was warm it was ok aside from having a louder whine. Then after 500 miles I changed the oil from the Penzoil that was in there to Mobil 1. Now what was funny was immediately I noticed that the turbo would not spool up as quick. Prior to oil change I had to feather the gas to go anywhere because I feared damaging the turbo till it truly warmed up. Now I can get on the gas a lot more and the turbo doesn't seem to be as touchy. The turbo also is alot quieter more like my 84 water cooled one. It is almost like the Mobil one is more like Molasses and is slowing the turbo down. I am not complaining because this is good for me as I didn't want the expense of replacement. Does anyone have any experience with this? I would really like to find that the turbo is ok and I can use it. If I get on it the boost gauge will go to about the 1:00 to 2:00 o'clock position and the car has good enough power. I just wonder why did was the turbo so noisy and spin so freely with the penzoil.