Machan, may be one of the following reason,
1- Leak from tappet cover- cover eke uda balapan cracks thiyenawada kiyala,samaharawita cover eka aluthen daana wei.
2-Engine Sump leak- Check with a mechanic. Podi leak ekak num hadanna puluwan. Nathtahm sump cover 1 daanna wei..
Check with a...