my atos odometer has reached 160,000++, it's 2003 yr car and now lying in workshop coz i've problem of starting my car when my engine cools down in the morning. this happened twice in this wk.

besides that earlier on, my car was overheated and the mechanic has removed my thermostat.
that time while fixing the overheat problem, the mechanic got poured in water while the engine still not totally cool down..white smokes coming out..n duno my gasket got spoilt or not because of this. Ever since then, my car engine always need to top up water everyday, ~250ml or lesser. but when the water is poured into it, the water storage tank water level will increase and i need to pump out the extra water too. it has been few wks like this but only recently i sent to hyundai workshop to fix due to the hard starting problem.
the hyundai ppl told me may need to overhaul my car and gotta spend around 3k perhaps to fix it. my car value i guess is around 10~11k now. i'm not very sure.
but jus wondering whether it's worthwhile to fix it or sell it directly??
can any of the forummers advise me. but wondering any 2nd hand dealers will accept such car or not. if trade in to buy new car, also duno whether they will accept faulty car.
appreciate for your guys kind feedback
