I have a 2000 saab 9-5 and the past few days it has been making this whining noise while i was accelerating than today it started making a rattling noise almost while it the whining was happening. Than i was underneath it trying to figure out where it was coming from but it stopped making the noise. But started puffing whitish blue smoke. Than when i tried to drive it away from where it was the smoke got REALLY bad and it started making this weird tick and shuttering, it ticked a few times than stopped than did it again and died. It will start and drive now but it has really low power and smokes really bad. I feel like it could be the head gasket but there isnt any oil in the antifreeze or antifreeze in the oil. But it does seem like there is oil in the tail pipe. Any ideas on what it is? or does it sound like a head gasket? Any help would VERY much appreciated, thank you.