Bubbling from coolant reservoir

[andrewcweaver]

Hi all,

I was driving home the other day and noticed smoke from under the hood, so I pulled off to the side and popped the hood. The coolant reservoir cap had come off and coolant was all over everything. Limped it home and let it cool off, added some more coolant, and checked oil cap to make sure that the oil wasn't milky. All checked out.

Next day, I wanted to check and coolant level in reservoir was very low again, and the bubbling and smoking was back, and cap was loose again - almost like there is so much pressure that it's coming unscrewed itself. Is this cause for alarm?

Thanks

 

[Maddmatts]

The cap should be making a tight seal and have noticeable resistance as you screw it on or off. If it comes off effortlessly, then the seals/o-rings are probably missing or degraded. It shouldn't be backing out on it's own.

I'd say find a replacement cap and see if it fits tighter. GM P/N: 13502353

 

[Natesriv]

new cap time.

 

[2014 Blue RS]

There's at least 1 thread about disappearing coolant. Sounds like you may have found the culprit.

 

[carsNskis]

I've had a coffee maker sound from what sounds like under the glove box for the last 10k miles, but it wouldn't repeat at my dealership... it burped the other day... noise gone along with about 1"of coolant in the res... no coolant I the oil (checked for safe measure)

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