Coolant leak..
 

I am very new here, I know very little about my car so please be nice. Received a call today from my wife regarding my 04 G35 coupe.. It was overheating and coolant was leaking.. White/grayish smoke from hood was coming out.. She did turn the car off immediately to not harm the car. No smoke from exhaust. Any clues or advice would be much appreciated..

Pressure test the radiator. The cars 10 yrs old and has a plastic radiator. Its probably cracked. I have an 04 coupe and mine went about 3 months ago.

I forgot to add that on the way home my wife said there was a squeak/rattling noise that wasn't there prior. I will do that! Thank you very much! I really appreciate it.

Sounds like you lost the water pump (belt squeaking) and it over headed a bit. Also look for a burst hose.

Could be the thermostat didn't open up, leaking radiator, water pump not circulating fast enough (rare), radiator cap, and bad hoses.

Pressure test like someone mentioned would let you know if there are any leaks. You can rent the kit for like 200 bucks at AdvanceAuto. You get your money back when you return it or pay a mechanic to diagnose it.

The water pump is actually driven by the timing chain and it's under the timing cover. The bearings go out (happened to mine) or maybe the fins wear down to nothing. But, that belt squeak could have been from coolant on the drive belts?

There are so many possibilities everything we post will be a guess! Blown hose...we have a few! Water pump or radiator, could be either! Have your car towed into Nissan, by pressure testing the system they'll find the culprit quickly or maybe they can tell by lifting the hood?
Gary

Solved !
 

Where the o ring and the tank is it cracked (radiator) I pressure tested it. Thank you all for your help! Recommendations, I'm looking at an Aluminum radiator (Nismo) what do you think?

Wish I did. I was in a time crunch and had to go with a stock replacement (plastic), but at least it has a lifetime warranty.

Couple tips tho:

1: replace the thermostat while you're at it (cheap insurance)

2: be sure you're familiar with the bleeding process when you refill the coolant. It tends to be quite a pain in our cars.

I bought one for 60 bucks on eBay almost a year ago going strong, lol. If you want to spend the money on a Nismo by all means.

The thermostat is attached the metal housing, but try sticking it in a pot of boiling water and if it operates correctly then you don't need a replacement. Buy a Lisle Spill Free Funnel it will help with bleeding the air out significantly. Changing the rad wasn't too bad you need to move the A/C lines slightly, unscrew it from the condenser, and the bolts are hidden under the hood cowl I think it's called. I'd also inspect your hoses make sure they're sound, since they are 10 years old. I bought a nice set of silicone hoses from Z1 motorsports.

Sounds good I will do that! I didn't know where the thermostat was at hut I just found it thank you! Thank you very much! Much appreciated! I will get the hoses.

Dude, the thermostat may still work properly, but its 10 yrs old. They cost $20 for a new one. just buy a new one, or you're just riding on borrowed time. It'll give you peace of mind, cuz if yer therm goes 2 weeks later yer gonna be kick in yerself right in the a$$.

Also, there are "fail-safe" thermostats (which I would recommend). They're a few more bucks, but if they ever fail they fail in the open position.

In getting the thermostat tmrw ! :) ill get that one. (Fail safe)

i'm having similar problem. Is your problem resolved after replacing thermostat??

If your car is overheating and you want to bring the temperature down fast turn the heater on. But you should definitely turn the car off as soon as that happens. And if you have animals be careful because dogs and cats are attracted to the sweet smell of the coolant. They have a anti serum for cats but not for dogs :(