P0011 codes on 2002 infiniti I35

Question

My car overheated about 5 weeks ago, the needle got slightly above the mark just before the H. I keep driving it for about 10 minutes after I noticed the temperature rising, then out of a suddent, the temparature droppped to normal level. after that incident, the engine started with a barely noticeable know noise, as I drove it, the noise kept getting louder. until I figure it was not normal. my mechanic reac the P0011 & P0021 codes and is telling me that the intake valve timer control (both of them (need to be replaced. is this all that is needed? the car is 194K miles on it and I'm in the fence as to wether to fix it or not. each sensor is about $300, + labor, so this is a problem for me, any advice will be greatly appreciated, thanks,

Answer 1

The most common cause of the problem is dirty or low oil. Since the Intake valve timing control solenoid valve uses oil flow to control timing, dirty oil can cause the valve to stuck open or close. Before replacing the valve, change engine oil (along with the oil filter) you can also do an oil flush and and reset engine code. if the light comes back again the intake valve timing control solenoids will have to be replaced.