Totally Weird Coolant thing going on

[Setright]

There is air in my coolant. Well, some sort of gas 'cause in the morning there is the sound of a babbling brook inside the cabin. Presumably from the heater matrix.

 

NOW, I would of course suggest HG's to anyone who asked me on this. However, the car is four years old and has only 45k miles on it. And NO, it's not an EJ25, it's the EJ201 as mentioned in my signature.

 

I opened the rad cap one morning to try to catch the air "red handed" and idle it out of the system, but there was coolant to the brim of the radiator. Midday today, on a medium warm engine, I opened it again, and there was the tiniest drop - probably just not finished sucking from the overflow. Idled it for a few minutes 'til it hit the brim again.

 

Just got home and thought I'd look at things before switching off. Popped the hood and a look in the overflow tank revealed a slow stream of bubbles. (My old Legacy used to do this for AGES after a coolant change...)

 

Engine still running, squeezing the upper radiator hose, it does feel softer than I recall from my Legacy, but I can't be sure that the pressure is too low.

 

Yes, I will get the dealer to give a new cap - only bought the car three months ago - but I just needed to share this with everyone.

 

It seems others are experiencing the same things at the moment - very odd.

[blitz]

Setright, you're describing something that I've been experiencing on my 2.5 II for a couple years now. The best way to describe it is the "slow boil". After a drive, I can always force vapor out of the cooling system by squeezing the top hose. If I don't squeeze it out, I sometimes get the gurgle noise when I blip the revs to 2000.

 

My theory is that incomplete air removal from the cooling system after changing the coolant begets a slight perpetual vapor bubble formation during subsequent normal operation.

 

My concern is that this leads to the runaway situation of: minor hot spotting -> dimensional distortion -> minor gasket leak -> combustion gas entry -> overheating -> warpage. I'm going to get that funnel-tool thing and see if that doesn't make a difference.

[Setright]

Just came from the dealership...

 

"Never heard of a bad rap cap...yackety yak....try bleeding the system...blah..blah..blah...."

 

 

WHY ARE ALL DEALERS LIKE THIS????

[Legacy777]

Really wonder if a new cap would help.....it's probably something I should look into.

 

Also I think if your coolant level in the overflow is below the low mark the system has the possibility to suck in air which promotes the gurgling.

[Setright]

Well, I think I will remove the overflow bottle and check the bottom of it for gunk. Some slimely build-up is to be expected, and who knows how it might affect the stability of the system.