ive got a astra turbo coupe z2olet ecotec . the problem is the idling it idles nicely then drops then picks back up at normal tick-over again. this happens mabye once every 20secs the engine shows no code faults . any advice??
sounds like the idle control valve mate, if you have any warranty get them to replace it, if not just take it off and give it a clean and then a very light oil (not WD40).
to neilc thanks for reply.probably take it to vauxhall get them to change it.but ill try to clean it first but i must be a thicko . where is the idle control valve on the z20let
would the bailey dump valve mabye be at fault worn seals etc.