My Lexus Sc 400 V8 had recently been running a little sick it was lacking power on take off and was lagging and possibly miss fireing or not running on all eight cylinders. It at first felt like it just needed a tune and timing service and maybe new fluids but after the car got going it seemed to get up to speed. When in the low gears and take off it felt extremely sluggish and sometimes when I would plant the accelerater it would appear to miss fire or slip I just wasnt getting any torque. I had recently replaced the altinator and every thing seemed to be running as it was but then I was driving along and accidently slipped from drive into low gear doing approx 70km/hr the car shot straight to high revs but then when I put it back into drive I noticed that it was not getting any power and was rattleling and running very sick. I couldnt get any drive power at all but the car remained on and the engine was still running, with no problem to the ignition or overheating.I notice some rattleling and ticking sound and it felt like the sequence and timing was all out. I let the car sit a day or so but it still wasnt running any better. A mechanic said I might have slipped a timing tooth when I dropped it back to high revs from such a speed taking into account the car probably needed a serious tune and time before. Not many of the mechanics have had had much experience with the soarers (because theyre imports in australia) or the situation I have mentioned and I would be greatly appreciative if you could give me any diagnosis or ways to avoid being over charged with unesscessary work and problem appraisal! Im not on a great income and am trying to minimalise cost and avoid being ripped of through miss diagnosis please help!