Air in the 3.6 Cooling System

[Mr Miami]

Not a specific Gladiator question (I just changed the thermostat in my '16 3.6 Wrangler) but the same should apply to both of my 3.6 Jeeps. Anyway, I keep reading everywhere that you have to be careful about air bubbles in the cooling system and it is best to jack the front of the Jeep up when adding more coolant and squeezing all the hoses a lot and whatever else to get rid of the air.

My question is, if there is indeed some air in the system, won't it just work itself out over time? The new thermostat (Mopar) is supposed to be 203 F per the specs and the Wrangler does now operate between 195-210 F per the readout on the dash. (For what it's worth, my '24 JTR operates a few degrees cooler at about 195-200 F normally).

If it it is operating per the specs, why would I care if there was an air bubble or two somewhere in the system? When I changed the thermostat I lost about 2 liters of coolant but replaced it with new Mopar stuff. So it is full (I think). I have checked it several times in the past week and it appears fine and the recovery thing is full.

Am I over-thinking this or being too anal?

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[Mr Miami]

I guess my thermostat is ok.

 

[joanny]

You're probably overthinking it a bit. Small amounts of air will usually work their way out over a few heat cycles. The concern is when a larger air pocket gets trapped and prevents proper coolant flow or causes inaccurate temperature readings.
If it's holding temp normally, the reservoir level is stable, and you're not seeing temperature spikes, it sounds like the system is doing exactly what it should. I'd just keep an eye on the coolant level for the next week or two and call it good.

 

[Mr Miami]

You're probably overthinking it a bit. Small amounts of air will usually work their way out over a few heat cycles. The concern is when a larger air pocket gets trapped and prevents proper coolant flow or causes inaccurate temperature readings.
If it's holding temp normally, the reservoir level is stable, and you're not seeing temperature spikes, it sounds like the system is doing exactly what it should. I'd just keep an eye on the coolant level for the next week or two and call it good.

Thank you. I would never have given it a second thought until I have read all the things about air in the system. I appreciate your comment.

 

[Bandit’s Lair]

Whenever I’ve done a radiator the vehicle always gets a good shaking during the full portion. Don’t know for sure that it does anything but it makes me feel better. Just grab the bumper and shake the vehicle back and forth both ways and some up and down every so often. It’s therapeutic.

 

[GuzziMoto]

In an ideal world the radiator cap would be the highpoint of the system and everything else would cascade up to it. But the reality is there are typically other high points in the system where air can collect. That is why many systems have one or more air bleed screws to allow you to bleed the air in those places out. That is also why a radiator funnel can be a good investment.
I have not yet had to mess with the cooling system on the JT, I hear it does not have an air bleed screw. But I would think getting all the air out can still be tricky. Putting the front end up in the air, and using a radiator funnel, would be what I would do. A set of ramps are usually enough to get the front end up in the air, but if you have a berm or hill that would work. And the radiator funnel is easy to use and helps keep you from making a mess.

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