So last week my 06 automatic g35 coupe over heated when I was driving it home. I let it cool down and drove less than a mile at the slowest speed I could to my house. The over fill tank had a crack in it and had leaked out all of its fluid so I replaced it with an aluminum after market overfill tank and tried seeing what the problem was. Since thermostats are $20 and an easy install, I emptied the system and flushed it with distilled water then replaced the thermostat. I capped everything off and filled it with coolant and began the "burping" process. I had the radiator cap and the air bleeder open. I ran the car with the air on and kept squeezing the hoses to get all the air out. I ran the car for over 45 minutes at idle squeezing hoses and checking if coolant was going through the lower radiator hose. The lower hose never got to the same temp as the upper and after about 45 minutes at idle it finally began to start overheating (Shooting coolant all over my engine bay from the bleeder valve and the open radiator). I let it sit over night and same thing today, can not get the coolant to flow through the lower hose and into the system. Please help me lmao

 

Thermostat, did you test if before doing the install and was it a Nissan item or one you purchased from your local auto parts store? Just because they're new doesn't mean they'll work correctly! Distilled water is a great idea, but you should have a mixture of antifreeze 50/50! You could pull the thermostat and test in on your stove (pan/water) and begin the process all over again or make a visit to your local Radiator shop and have them do a pressure/flow test to solve your issues!
Gary

 

There's a very high probability that you still have air in the system, our cars are notorious for being difficult to bleed. The real issue to me is what caused the car to overheat in the first place. It could be a bad thermostat, a small leak somewhere, a faulty radiator cap, a failing radiator, failing fan or fans, an electrical issue of some sort, etc. Gary gave good advice, test the thermostat and get a pressure test done. If those test OK then test the fans and check all of the associated relays/fuses connected to the cooling system and go from there. It helps a lot when you're bleeding the system to jack up the front end of the car and to use a Lisle funnel (or another spill-proof type) to keep as much air out of the system as possible.