Where you guys quote it RM 300-400? It's really cheap, cause my friend did top-overhaul on his Nissan, cost him RM 900  (workshop in Bdr Sunway)

I am just thinking of doing top overhaul for my Nissan Sunny too 
No blue smoke, but valve tappet is making loud "tat tat tat" noises around 2000-2500RPM.Only can be heard outside.

Otherwise the car's engine still can do wonders in power.

What's the car odometer reading when this happens ?

What's the car odometer reading when this happens ?

just wana say, the tappeting sound is not a good indication of ANYTHING other than the valve clearances lari (and frankly it can lari very easily without causing any issues...) if u really wana diagnose oil loss issues... take note of whats coming out of your pipe in different conditions (e.g. valve seals, spew smoke during heavy deceleration where theres a vacuum pulling the oil in through the seals, constant smoke, possiby more during higher rpm's - rings)

even better would be to do a comp test or maybe even check ur plugs (visual check tells you alooot)

how much are you loosing? only 2 other ways it can be lost (tho im quite sure its being burnt, maybe in quantities too small ot notice or only when ur moving at speed)
i)leaks, should be quite obvious
ii)ur screwed and its going into your coolant... you should find oil in ur coolant (honestly unlikely cause it should be everywhere at that point)

At 230K odo with a bit of tik tak sound, as suggested by lsm , it's likely valve clearance lari .........
in particular when no valve adjustment was ever done on this engine, ever.
One doesn't have to remove cylinder head to adjust valve clearance by competent mechanics and it involves only replacing gasket for valve cover .......... and I don't call this as 'top overhaul' which equates to more $$$.

As for coloured smoke , it is quite difficult to 'see' with untrained eyes and it may be wise to refer to an honest mechanics. Btw, what's the oil brand/viscosity grade/API ACEA specs that this engine has been using before and during oil consumption occurs ?

At 230K odo with a bit of tik tak sound, as suggested by lsm , it's likely valve clearance lari .........
in particular when no valve adjustment was ever done on this engine, ever.
One doesn't have to remove cylinder head to adjust valve clearance by competent mechanics and it involves only replacing gasket for valve cover .......... and I don't call this as 'top overhaul' which equates to more $$$.

As for coloured smoke , it is quite difficult to 'see' with untrained eyes and it may be wise to refer to an honest mechanics. Btw, what's the oil brand/viscosity grade/API ACEA specs that this engine has been using before and during oil consumption occurs ?

At 230K odo with a bit of tik tak sound, as suggested by lsm , it's likely valve clearance lari .........
in particular when no valve adjustment was ever done on this engine, ever.
One doesn't have to remove cylinder head to adjust valve clearance by competent mechanics and it involves only replacing gasket for valve cover .......... and I don't call this as 'top overhaul' which equates to more $$$.

As for coloured smoke , it is quite difficult to 'see' with untrained eyes and it may be wise to refer to an honest mechanics. Btw, what's the oil brand/viscosity grade/API ACEA specs that this engine has been using before and during oil consumption occurs ?