I recently changed my block heater and the thermostat. I put the anti freeze back in and noticed it was leaking from the thermostat. I took it apart and put gasket seal on it and put it together.

No anti freeze leaks I topped it up. Let it run and topped it up again. Went for a cruise and my temp gauge was being wonky, example it was going over the halfway mark, but would drop low again. This would repeat. Next morning I checked my antifreeze. My levels are fine none has leaked.

It's winter time here right now so the weather is -20ish. I am concerned for summer with warmer weather.

Any advice or input from the community here?

I drive a 1992 B2200, standard, fuel injected, extended cab 2.2 litre engine.

 

There maybe an air bubble in the system.

 

What's the best way I would Go about solving an air bubble issue?

 

Are you checking the coolant level at the radiator cap or the coolant jug? You can't trust a coolant jug. If it is truly full and the temp gauge is still acting up these are the possible causes.

1- Temp sender or connection
2- Thermostat upside down or just a bad thermostat
3- If it only overheats driving highway the radiator is partially clogged
4- If it only overheats at low speed driving or at idle the fan clutch is suspect or the condenser fins are clogged and not allowing air to cool the radiator fins.
5- Blown head gasket
6- Coolant bypass hose/pipe clogged

 

Yeah, the B2200 does not have an coolant air bleed crew like my two 4-cylinder Frontiers do.

Jack up the front of the B2200. Take off the radiator cap. Start the engine, turn the heater on full too. Let it run like 20 minutes, continually topping off the radiator with 50/50 coolant as needed to keep full. After a while, the radiator/cooling system will not accept any more. Install the radiator cap. That's it.

Oh yeah: remove the jack before driving. These engines are somewhat difficult to get all the air out after doing repair such as yours or routine coolant change.

 

Thanks for the input guys