Hi guys I’m gonna try to be as depth as I can be in this so I have a 2005 g35 coupe which has always had coolant problems with it first day I got it it overheated but that fix was easy as one of the hoses broke and had a very visible leak so I fixed that fast forward to now and damm idk where to start so two months ago car overheated pulled over and temp was high for a good hour drove it home very slowly when it cooled down and decided it was air bubble so I bled it which was a pretty fun experience then another two months later car started having temp guague going up and then it would go back down by itself and I thought it was just faulty dash because no other indicators of car overheating popped up so this happed frequently then one day car overheated but temp went all the way to hot which is new because this never happened pulled over and coolant coming out of the resovoir overflow valve and I took off the resovoir cap (not radiator cap) and faint smoke was coming from there so here I am now i don’t know what to do or where to go forward from here I don’t think it’s headgasket because no white smoke from exhaust or milky substance in oil also update : I drove the car 3 days without any issues so I thought it fixed itself then today randomly I picked up my friend and temp started to go up at first it was js a little but I knew it was gonna go up a lot and it had not fixed itself and I was right temp went up really high after when I was driving it home I noticed the car doesn’t blow hot anymore only cold like heater doesn’t work I don’t know if this is related but anyways after I brought it home I replaced radiator cap on it and it’s still acting up so guys my question is how come it drove fine for those three days not acting up at all

 

At this point, I would test for a head gasket leak.
A tester is pretty inexpensive.
youtube!

Also make sure your fans are working!!


If you have cash, www.yourmechanic.com is a good mobile service. They come to your house. It's like having a paid friend.