Temp gauge fluctuates intermittently

[afewsubarus]

2006 Outback 3.0. Temp gauge fluctuates intermittently sometimes almost goes to red but then almost as soon as it tops out it drops down. When the car is turned off bubbling can be heard from under the dash. The radiator and thermostat have recently been replaced. I believe I have properly bled the air out of the system. Should I be concerned?

[3Pin]

Whenever your temp gauge is showing not normal ranges, I would be concerned.  Sure sounds like you have air in the system still.  Look up how to bleed air out of your system.  Others may pipe in based on your specific model.

 

[lmdew]

Use a Subaru thermostat?  If you used an aftermarket change it.

Why did you change the radiator and thermostat.

Air bubbles and black oil slime in the overflow tank?  HG.

Edited March 7, 2019 by lmdew

[afewsubarus]

Radiator was replaced before I purchased the car. Changed the thermostat to try and remedy the situation. No air bubbles or contaminants in overflow tank.

[heartless]

hearing gurgling in the dash usually means air in the heater core. it needs to be bled more.

 

[carfreak85]

Remove the radiator cap, jack up the front end as high in the air as you can and run the engine with the heater on hot as you massage the heater core and radiator hoses.  Look for bubbles.  Wait for the thermostat to open then let the cooling fans cycle a few times.  Close system, lower car, drive around and observe temp gauge.