variable valve timing failure One day the car went from running 'perfect' to intermittently back firring and blowing white smoke out the rear. I took the car to 3 different mechanics before I found the correct diagnosis; replacement of the variable valve timing actuator valves: perfect fix to a failing engine.

Update from Mar 3, 2017: Engine lost power and lost 1 quart engine oil every 250 miles, full tune up failed to bring back power. Strong exhaust gas smell inside car while driving. Compression test done: 2 cylinders had 120 PSI, 4 cylinders had 42-55 psi: wet and dry compression testing done. I was using 5-30 Toyota oil, switched to 10w-40 oil, problem was still bad. Mechanic suggested to run 20w-50 engine oil in summer; now car can run 2,000 miles before it uses 1 quart oil, mpg went from 32 mpg to 24 mpg due to thick oil.

Update from Mar 3, 2017: Metal filings are now present in every oil change. Last oil change I did produced a whole heaping handful of metal filings. (that is pretty bad). Only so much metal comes off before total engine failure. I am disappointed with this car. Bought used with 89,000 miles on it, oil changed every 3,000 miles; I have all receipts going back to the day it was new. I thought Toyota cars were 'good' and would last; I am disappointed. My neighbor has an identical car to mine, he has over 340,000 miles on it and it just keeps running.