Infiniti Repair Questions? Ask a Mechanic for Answers ASAP
Ok so when all this happens the check engine light never comes on ?Let me ask you has the engine been checked for vacuum leaks or the thermostat changed and the cooling system bled?
Not if the thermostat is stuck open it would not .I think one of two things you have a bad coolant temperature sensor and the coolant has air pockets in it causing the idle surge or the thermostat is stuck open which will also cause this issue .This is where they need to focus.I would change the thermostat and completely get all the air out of the system and this should fix the issue .this is the next step.Hoped this helped.Please rate excellent service so I can get credit for my help thanks .Bonuses greatly appreciated.
OK this is all due to a stuck thermostat or air in the system I still doubt it's the headgasket. I would have a shop drain al the coolant replace the thermostat and bleed all the air out of the system. This should take care of the issue the key is to bleed the system correct to remove all the air.