hot blip: air pocket or thermostat?

[Jasminka]

The old VS is just used a shopping cart nowadays. After warming up in the morning, the temperature gauge goes 3 marks above normal, then quickly settles back to normal.
On return trip it does not, but the motor hasn't cooled down fully. I was told this is caused by air in the system. I have bled it twice: first by removing the radiator cap with nose uphill and topping up as the coolant went down, then next day used the bleed screw, but this blip still happens.
So other possibility would be thermostat? It had overhaul last year - the thermostat, radiator cap, sender and heater valve were all replaced. Radiator and pump were replaced 2 years ago.

 

[Clubby_Don]

My old vs v6 use to do the same..
I found it was the T piece for the coolant/aircon connector had a crack..
It would leak water slow while cold but when its warm it would start to spray out fast and you couldnt even see it as it was going straight down onto the road..
This would cause air in the system and when u stop the temp rises cause the air around the sencor is steamy and you get a false reading on the temp gauge..
Maybe check that first..
Could also be s air pocket in your system as putting the car on a downhill wont always fix the problem..
When i replace my coolant i undo the top hose where the thermostat is and pour about 1.5L of coolant in there first and another liter in the radiator.. them i start the car for 30 seconds top ot up full and run the car for another minutes while topping up the coolant when needed and i never run into any problems this way..