Altima issue

[Cjestes2009]

Thanks for the add iv been a mechanic for over 35 years and I'm stumped on a vehicle at the moment
2015 Altima flushed radiator and heater core replaced the 2 thermostats and temp sensor and burped the cooling system. It will run cool even with fans unplugged when it does get warm drive down road and motor get cold again and I test temperatures with my temperature gun

 

[AutoMechanic]

Did you use OE thermostats? Is the radiator bad or something?

 

[Cjestes2009]

Yes oe and radiator flushed out good no leaks even did coolant pressure test

 

[Kurtatron]

Make sure the lower radiator hose does not have an air bubble. Give it hard squeeze while burping the system. A big Air bubble can impede the coolant flow even when all else is working properly.

 

[Cjestes2009]

Iv drained system 5 times and reburped the system each time and same outcome each time iv even checked all hoses with temperature gun to see if air was trapped in them

 

[fsdork]

Is it possible a thermostat is faulty and is staying in the open position? This would allow coolant to circulate and bring down the engine temp.

 

[Cjestes2009]

Replaced the thermostats 2 times in a week and pulled them back out and tested them in pot of water

 

[mk378]

It overcools / fails to warm up?

Really the only thing that can cause that, if it is actually happening, is the thermostat is not blocking the coolant when it is cold.

Confirm actual engine temperature with live OBDII reading. Also could check if the heater is making hot air.

 

[WylieCoyote]

"when it does get warm drive down road and motor get cold again"

Since you've swapped out thermostats, I'm starting to wonder about the temperature sender. How cold is 'cold'? Is the needle actually moving back to "C" while you're driving down the road?

 

[Boomer]

Wrong thermostat??

 

[zrxkawboy]

So the temp gauge reads too cool, and you’ve confirmed that with an IR thermometer. Where did you take those readings, and what were they?