2007 Hyundai Starex Engine

If you've noticed a louder engine lately, has the performance changed at all? Have you started using oil?

The loud sound was heard lately but the performance has not changed. Engine oil consumption has no problem since oil level remains the same since last change. Although, oil change is due within 1,500 KM.

Id just keep an ear on it and let me know what happens. It doesn't sound to be much of an issue. Check your belt and the pulleys for frays or pulleys out of line or rusty centers. It could mean a pulley bearing going bad

First of all, thank you for your continuous reply on my concern.

I have checked belt and the pulleys and in found them good shape. The belt was replaced 6 months ago. Is it possible that the unusual sound is cased by the big clearance on rocker arms or defective hydraulic valve lifters?

It is possible. But if you're not having any drivability concerns, I wouldn't worry too much about it. You could always try an engine oil flush service first before doing anything else to see if it quiets the lifters

I will try to an engine oil flush, anyway it is due for oil change. Thank you once again and give feed back to you.

Cool thanks! Glad I could help. Let me know if I can do more