Quote Originally Posted by boybi View Post
how about for diesel engines? wala naman spark plug ito get dirty.
Some diesel engines have glow plugs especially earlier ones, they can also collect carbon deposits kaya when one buys a used car sometimes it's also good to ask kung dahan-dahan lang parati pagtakbo ng kotse dahil kung ganun halos puro carbon deposits siya so one needs to drive it hard once in a while.