Hi.....i have a Hyundai santro Xing XG bought in year 2005. I have been having issues for over a year that the car would give a jerk while driving. In the beginging ,more than a year back, i just used to feel a very little jerk while idling but no problem in driving. Bought this to the notice of the Service Center but was given some lame explanation and told that it won't effect in any way. But for the past year or so i started having this knocking while driving as well, so this time went to another Service Center as the one owned by dealer near to me got shifted. Now this one is also an Authorized Service Center of another Hyundai dealer. So they did some work and fixed the issue where the jerk was very slight when idling. So after some time it came back again and went to get the car serviced and got the issue fixed again. So after several time of issue re-arising it it finally has been diagnosis that the Engine need overhaul (have got it checked from 2 different service cneters) as there is oil coming in spark plug in one of the cylinders. Now my car would be 3 yrs old and has just run 38k KMS and i have got it regularly serviced. Now my concern is why it happened as its just under 40K KMS and also how would it perform and what would be its life after the overhaul. Any comments?