when was your cam chain last changed as iirc thats not too far from the service interval. as for oil i always have put 10/40 in, dont buy cheap oil. also change the oil filter and sump plug.What oil would you recommend i put in my car? it is a 2002 SRI 150 z22se ENGINE WITH 74,000 MILES On the clock,
2002 was the year that Vauxhall recommended 10w/40 semi or 5w/30 fully synth.10/40 Semi Synthetic.