Hey ya'll, so I've been having overheating problems with my 06 G35 for the past year. I changed out the thermostat (oem), radiator, rad fans (they look like they are working fine, turn on at 200 f) , all the hoses with new Z1 ones, and I used OEMTOOLS 24444 Coolant System Refiller Kit to refill the coolant without any air. I left it holding a 27.5 psi vacuum on the system for around 10 min and it didn't drop at all. The coolant doesn't look like it has any oil in it, and vice versa so I don't think it's a headgasket issue especially since I've been daily-ing it around town the past year without a tstat when the weather was cooler. I'm starting to think it might be the water pump but wanted some feedback before taking it to a mechanic for that because I'm too scared to mess up the timing. I was also thinking about throwing on a second water pump on one of the radiator hoses as a ghetto fix but idk how well that would work. Any feedback is welcome. Thanks ya'll.

Q: if you added all this stuff listed after it was overheating, then I would check to see whether you have a head gasket leak.

They make kits to test this and pressure as well....I would test for this.