okay I drive a 2004 G35 coupe auto with 250k miles on the dash but I recently installed an engine with less miles on it about 100k. I did a coolant flush about 3 weeks ago and bled the air out the system correctly because it wouldn’t overheat. But after turning off the car or when the car is on sometimes it would begin to leak from the first picture. The second picture is how that pipe/hose looks like from above. And when I say it leaks, I mean it leaves huge puddles of coolant on the floor; causing it to overheat again. I have a video of it leaking but it doesn’t let me post it so if I can get some insight on how to fix it I would really appreciate it, thanks..

 

The best way to find leaks is to use a pressure tester and an inspection mirror.

You should also check out some of the head gasket leak detector. You might have a blown HG on your engine. Lisle makes an excellent leak detector kit.

Rent the pressure tester from a local auto parts store, they may also rent the leak detector but you'll probably end up buying it and the fluid (it's like $50 to buy the kit) then you can sell it on Craigslist and recoup the cost if you don't want to keep it.

 

Speaking of leaking coolant, I have to replace my radiator again. Anybody tried Walmart's Supertech extended life (yellow cap)? I usually buy the one with the black cap (green coolant), but they ran out. Never used the yellow version. Guessing it should be fine to use on the g35.

Perhaps I should go with the blue/pink coolant now? I don't see the need, since I usually find those on newer Nissans.

 

Blue is for 2009+ You need the green Nissan coolant.

EDIT: The coolant contains exactly chemistry to not erode various parts inside the coolant system. The exact makeup of the plastic, the exact grade of aluminum, the exact metallurgy of everything the coolant touches. Engineers determine the coolant chemistry to work with the EXACT metals and plastics used inside their engines.

Engines evolve, different materials, different alloys, different types of plastics. The coolant evolves to match these changes. I would only use the recommended type of coolant.

Unless it's a track car, then you just use water

 

For that pipe, there is an O-ring seal inside for the meeting between the aluminum casting and the steel pipe that leads to the upper radiator hose.
I would consider checking your bleed port too, as those are notorious for actually breaking apart and leaking a ton of coolant. Z1 has an aluminum replacement, I have 2 of them and I highly recommend them.
It would not hurt to go around and check all the other heater hoses and misc coolant piping for leaks and cracks while you are there and have to bleed it again...
https://www.z1motorsports.com/water-...ng-p-8356.html
https://www.z1motorsports.com/coolin...e-p-11190.html

 

For coolant, I am running Pentofrost A2 green coolant. I ran the A3 blue variant in my Accord for several years without a problem.

 

Ahh dang it. I poured some of the new coolant in a cup and looks green-yellow to me. It's not as green as the stuff I use to get. Must be this new extended life formula. Although the ingredients on the back of the bottle are identical.