Does it mean the vehicle needs engine overhaul for replacing worn out valve seals on 2002 Mazda Etude 1.6,since there many different opinion regarding the blue smoke,high consumption of oil

SOURCE: ROUGH IDLE AND HIGH FUEL CONSUMPTION - HESITATION

Try checking your Spark plugs (they MUST be the right type, clean, and properly adjusted: and try adjusting your timing. Either or both of these could cause this type of problem Hope it helps. If so, don't forget to rate the answer, will you?

SOURCE: High oil Consumption, BMW M5

Look for Castrol TWS 10W60 Motor Oil. This car should not burn so much oil, you need to use a different kind. It is recommended by BMW as well. I also heard the VANOS isnt an issue anymore, can be fixed with a different MAFF. Good luck!

SOURCE: high oil consumption on 2001 Toyota Highlander- 3.0 V-6 engine

If you are using that much oil you either have a BIG leak or your BURNING oil through bad rings

SOURCE: newly overhauled toyota corolla 2e engine emits black smoke

I have toyota corona 3s engine it smokes black and fuel consuption is high we have changed the engine oil and cylinderhead gassecate but still black smoke is comming what should i do

SOURCE: Engine knocks and high oil consumption ,Toyota Hilux 3L Engine.

you have to change every thing. eveng the crank shaft must be done or pulished