I have a 2000 model s60 ts and while on tick over the idling is very erratic. It will barely level then spike and drop in revs.This also causes my lights to dim as the revs drop but return to full brightness as the revs rise. the car performs great while driving , only getting these problems while on tick over.
woould i be right to think this would be caused by the idle control valve , any suggestions and the best way to clean it would be most helpful. many thanks
steve