Hi, wonder if someone could please help as i don't know what to do.

i have a vectra 1.8 vvt engine.

on Monday i noticed that when warm their is a tapping sound.

i lifted the bonnet and their is a tapping as you look at the engine from the left hand side close to the belt covers.

I flushed the engine with clean oil and gave it a run.
The next day it was still the same so did it again but still no change.

the noise happens on start up for a split second ( i thought this was normal ) and then does not happen until ive driven 3 or 4 mile.

its still driving the same and the engine is smooth, can not hear the noise when driving only at idle or when in first gear.

had the AA out tonight as i had a warning light on the dash come on but went when i turned the ignition off and on, it was the car with a spanner.

AA man said the engine does have a tapping but did not know what it was, said the engine sounds fine and revs and all checked out fine.

has anyone had this problem, any advise would help.

Thank you.