Firstly i apologise for the caps on the title.
I have a Astra Mk4 2.0 Sri, 2000 W ref, done near on 88k. I have a problem which i dont have a clue what it can be and really want some help on this issue.
When car hasnt been started for a day or even say 3-4 hours and engine is cold when it starts there is a noise coming from the area around air filter, cam, timing belt cover.
Decription of noise:
best way to decribe it is if you tap key quickly on your keyboard. imagine that but it increases the speed of the tapping according the the rev's of the engine.
the noise starts when engine is cold but once engine has warmed up after even afew miles the noise has gone.
Ive had the rocker cover off to see if anything is loose all seems fine, checked fluid levels.
Cambelt and Aux belt and water pump changed december just gone.
Even had the Aux belt off and started engine the noise is still there which rules a few things out.
Ive done compression test on the engine i belive they were 1.190 2. 180 3.180 4.180 all seems ok.
I really am struggling with this problem please if any one can help i would greatly appreciate it even if your not sure but feel its worth checking, many thanks