2002 GMC Sonoma won't heat up past 150 degrees

gmc
sonoma

#1

I had a radiator split last summer. changed it out and now it won’t heat up past 150 degrees. i cleaned heater coil, changed 3 thermostats. 2 radiators and heat temp console. plus temp sensor.


#2

Thermostat installed backwards, maybe? Air bubble that just can’t get out?

How are you measuring the 150 degrees? With the car’s gauge or sender? Or something else? I wouldn’t believe the car’s gauge or sender unless I’ve verified it with another method.