as the title stated, i been having rough engine start up (overnight) whole car vibrate harsh knocking noise when i start my car to head to work.

did a bit of googling and was told its either bad oil change or lifter rod/pump going bad?

my oil change schedule are always on time (5000miles/ 6months) at the stealer in which they use syn-blend oil (not full syn) and were told its what lexus recommend.

its not giving me any issue yet, but might be an early sign, since my car is a hybrid the engine doesn't run the entire time, but when sometime the engine kicks in it knock again.