Hi guys, when my astra g is ticking over (1.6 8v) there is a very light knocking noise only a couple or so times probably about every ten seconds. I think its a noisy tappet. How can I stop this?
Also on tick over the engine sometimes revs up and down on its own. Now i havebeen told to clean out the idle air control valve. Where is this? When the engine is revved up and left at say 3000 rpm it still revs itself up and down?? And the exhaust starts to "bubble". Any ideas please?