Dirt and debris can clog the fins of the radiator which would obstruct air flow. Likewise, a air bubble- or, while rare, debris in the coolant- can impede circulation of said coolant through the system.

Have you checked the fans- yes, both of them, to make sure they are cycling ON/OFF and at full speed? If your car is "overheating" both fans should be roaring.

In the old days we would squeeze the radiator hoses (obviously wearing gloves) and rev the engine briefly. If the pressure on the hose changes with engine RPM's then likely the water pump is good. Not sure that method would work on these cars. However, as replacing the water pump is a very intensive job on these engines and will not be a cheap repair bill, I would get a second opinion before going that route.

 

OIl is clean? making sure its not a headgasket issue. You should get a headgasket tester

 

Did anyone resolve the overheating on the gauge
Last week in vegas when it was 108
car was idling almost an hour picking up my son & radiator gauge started going up & once I turned off the ac the temp went back down

Put new radiator fluid about 2 years ago & changed the thermostat yesterday
today the temp went up in the car after idling for 30 minutes
I notice the idle is higher waiting & once I turn the ac off for a few minutes it will go back down

mechanic checked & the radiator fans come on at 215 degrees

I do have a small crack in the radiator reservoir - & it leaks a little from there

 

The likely issue when a engine runs hot while idling is either due to insufficient air flow over the radiator or insufficient coolant circulation. Being that you replaced the thermostat you are likely good there with exception to potential air in the system.

1) Have you ensured that both fans are running at full speed when the engine runs hot? When hot the fans should be roaring loud. You can run the IPDM/er self-test to verify.

As the engine gets hot, the temperature gauge will start to rise and the engine idle will increase slightly. This is normal as the engine is trying to circulate more coolant/faster.

2) You mention a cracked coolant reservoir. Keep in mind that while coolant can leak out, air can be sucked back into the system. You could have a air bubble somewhere in the system that prevents the coolant from circulating.

 

thx for the info
just bought a new coolant reservoir & hope that helps keep it pressurized

Radiator fans come on around 215 degrees

I will check the link u left
🤙

 

 

just replaced today new reservoir- hopefully that is it

it only overheats when idling with ac on more than 20-30 minutes & fans come on a lil delayed

 

Replacing the reservoir won't resolve the issue of air present in the cooling system (which can lead to overheating). You need to properly burp the system or evacuate and vacuum fill. I've always used the latter but it involves a compressor and more equipment. Former is a $20-30 kit from lisle.

vacuum fill -
burp funnel (I think this one fits nissans)
Edit: The pic above does not look like a pressurized reservoir.

 

Mahalos 🤙- I will check each step

the ipdm test the fans came on but not as strong as I saw in video for the ipdm test

 

I have a 2013 g37 with the same problem except when I went to check my coolant level to see if there was a leak I noticed my coolant reservoir was completely full and theres no coolant under the radiator cap, I haven't added coolant so could there be a clog somewhere preventing the coolant from getting to the radiator?