I got a 2005 TL, and lately I’ve been overheating. I thought at first just faulty sensors (P0125, and P0118) and no coolant but it turned out that my coolant was leaking due to me pouring a whole gallon of universal antifreeze into the radiator. After I did this and driving around for a bit with a good temperature, the car then later started getting hotter and hotter along with making truck noises. After some looking around I saw coolant was leaking from behind the engine. Was wondering if you guys could tell me what this is if possible.

I do also plan on replacing the thermostat also since I know when was the last time it was replaced.

 

Turns out it was my heater control valve, car runs a lot better now.

 

make sure you burp the cooling system and get all the air out.