My G35 5AT vq35de is currently over heating even after replacing the radiator and thermostat. Initial issue was a radiator leak. I did multiple coolant flushes, I bled the cooling system 100% I am getting no more bubbles with a spill free funnel with the front end lifted, but I am still overheating as I pull out of the driveway. I am currently running no thermostat that helped me drive around normally for around 7 minutes until the heat starts to spike. Heater blows hot air but he radiator is ice cold to the touch even after hard driving & the hose gets hot where it connects to the thermostat but that same hose is ice cold lower where it connects to the radiator! I ordered a new radiator cap to see if that does anything I have no leaks with a pressure test & the fluid stayed blue with a combustion test. I am at a loss & do not know what else it can be I have been working on it for months now and cannot get it to stop overheating. If any of you may know what it could be help would be greatly appreciated!!

 

So the engine gets hot but the radiator stays cold?? I would think you dont have any flow then….which means your water pump isnt working.

 

Yea the radiator gets no heat besides one instance when we slightly vented the air out through the radiator cap when hot being very careful of course, the radiator actually got hot but we have been unable to get it hot again what so ever even after driving around for several minutes it stays cold. I was thinking it might be the water pump but it isn't leaking or making any strange noises, the upper radiator hose does swell up when revved & I can see water circulating when I rev the engine. Maybe it isn't circulating at idle? I do notice the temperature will usually go down when the engine is revved to some extent unless its already overheating.

 

I know you say that it’s blowing hot air, but have you been bleeding it at the coolant hose bleeder port? Sometimes you have to do it several times to get all the air out out of there.

 

Yea man I bled it from there too it just spays out fluid when its hot & coolant pours out when cold. I had an exhaust leak coming from my stock y-pipe that I fixed today with a Z1 Motorsports Y-pipe got some nice gains from that according to my butt dyno even with a passenger. It would be nice if I could ride around for longer than 10 minute sessions without overheating lol

 

Aftermarket radiator caps got stuck in the hose when test fitting! Pulled it out and car is now running fine!

 

LOL Thats a new one. Glad it worked out for ya.