what is the risks when mileage is higher than 140 000?

Hi moua. There are a numbers things that can come into play on a high-mileage engine not the least of which is a decline in fuel efficiency. The main thing you need to be concerned about however is the timing belt which may be overdue or close to overdue if it's only been changed once in the life of the car. I don't think too many manufacturers stretch their recommended timing belt change too much beyond 70K. Hopefully you know when the last change was otherwise you could be driving an expensive time bomb. You might be looking at fuel injector issues as well. It's should be too expensive to have the car given the once over by a dealer and if the car is in good shape you could save yourself a lot of trouble. Good luck!