I recently had radiator work done on my 2003 G35 Sedan.

Just some information and price points. I just made this post so some 16-yo HS punk can learn from my drama.

Only reason I knew something was up with my cooling system was that I heard the water noise in the heater core almost every time I accelerated. I checked the overflow tank, and it was low. When you refill, make sure you refill the radiator also. ONLY REFILL WHEN ENGINE IS COOL.

A week later, same water noise, overflow tank low again. Never saw any coolant dropping on the ground, but I did see little bit of coolant on the bottom engine cover.

Unless the leak is obvious, mine wasn't, test the coolant system using the cooling system pressure tester. Go rent one at ADVANCE AUTO PARTS, NOT AUTOZONE. The one at AUTOZONE is crap and will not fit/work for our cars. The one at Advance Auto Parts is very nice. I attached a picture below. Use the adapter #9, which fits our radiator cap. You'll see what I mean when you rent it. Pump up the pressure to about 13-15 PSI and you should start to see leaks. (88Kpa on the cap = 12.71 PSI)

My leak was right below the upper coolant hose, where the metal was.. very slow leak, thank god the car never overheated.. When the system was pressurized, I could see the water drip to the bottom engine cover.

I would've fixed the car myself, but my apartment only has a parking garage, so lifting the car was out of question. The dealer wanted $1500 for the job, my car is worth $3,500.

A shop quoted $200 labor if I brought my own parts. The radiator is about $75-$120 at rockauto.com or $480 for the OEM part. I didn't have the time, so I just drove to advance auto parts and used a $50 and a $20 coupon and picked up the radiator for about $135 out the door. It was Carquest/ToughONE brand. Not sure about the quality, but they were the only store that had it in stock.

I went to Kmart and bought 3 jugs of Peak Global Lifetime 50/50 mix coolant @ $10 each... Pep Boys had it for $6 each but not close to me.. Seems like a decent coolant according to bobistheoilguy.. personally I would goto the Nissan dealer and get the OEM coolant for $25 a jug and a gallon of distilled water and mix it myself. I didn't have the time.

Anyhow, the mechanic installed the radiator for $200, so the total cost for the radiator swap was just a tad bit under $400... He said no issues with fitment of the radiator.

Make sure to top off the coolant every morning for the next 3-5 days..

My car is 12 years old w/ 167,500 miles..

Good luck