Hello guys, I'm buying a Lancer 1.6GLX 2005, deal is almost final but i've noticed one issue. when car is started and in idle state engine knocks after short intervals and RPM jumps up and down and then become normal, and when AC is turned on it happens more often, ie knocking of engine and RPM jumps, can experts shed some light what mite be causing this, Owner says that it needs minor tuneup, is this the case?
