Coolant draining after shut down?

[avenali312]

So, I'm usually pretty quick to notice things that have changed with my car, but I'm having a hard time remembering if this is a thing when the temperatures drop for fall and winter.

After my daily commute, I've noticed the noises after shut down seem louder. Not the usual clicking and beeping like an AOL connection in the 90s, those are still there and normal, but there seems to be a newer and louder sound like a household vacuum accompanied by liquid pouring or gushing. Seems to be centralized below the HPFP somewhere. No leaks and everything looks dry on the outside, at least on what I can see from up top. No noticeable loss of coolant. No codes. Car runs fine.

I did have my oil cooler and oil stack gaskets replaced, but that was way back in August and no issues since (and also on the other side of the engine).

Video doesn't quite do it justice. It is quite loud in person to the point where my wife noticed it as well.

Thanks in advance.

 

[BudgetPhoenix]

Not sure why it would suddenly sound louder, but there are two auxiliary electric coolant pumps on the engine that circulate coolant for a while after the engine shuts off.

 

[avenali312]

Not sure why it would suddenly sound louder, but there are two auxiliary electric coolant pumps on the engine that circulate coolant for a while after the engine shuts off.

Yeah, that I am familiar with and figured it's related to that, but definitely way more noticeable all of a sudden (this week).

 

[BudgetPhoenix]

fwiw sometimes I hear that same coolant flowing noise sometimes I don't.

 

[avenali312]

fwiw sometimes I hear that same coolant flowing noise sometimes I don't.

Good to know, thanks!

 

[jay745]

You might have an air bubble making it louder. If coolant is flowing and no bubbles you don't hear it as much. Id probably burp the system. Letting the car idle with the coolant cap off for 30 mins or so usually does the trick.

 

[avenali312]

You might have an air bubble making it louder. If coolant is flowing and no bubbles you don't hear it as much. Id probably burp the system. Letting the car idle with the coolant cap off for 30 mins or so usually does the trick.

That does make sense. Thanks, I'll give it a try!

 

[OceanJack]

So I just pulled my turbo and had to bleed coolant, I actually started hearing this noise too when I turned my car off. I saw that coolant was a little low as well, topped it off and haven't heard it since. I'm guessing that all of the air must of left the system, but yeah, you're not going crazy. I don't have any codes, scanned with OBD11

 

[avenali312]

You might have an air bubble making it louder. If coolant is flowing and no bubbles you don't hear it as much. Id probably burp the system. Letting the car idle with the coolant cap off for 30 mins or so usually does the trick.

Went ahead and burped the system last night. Let the car run for 30 minutes with the cap off. My dad also said to run the heat for a while since it hasn't been used since last winter and that maybe after the work I had done in August there may have been an air bubble in the heater core or something. This new louder noise does align with me having to use actual heat starting last week as temps have dropped, so maybe? I let the car cool and topped off the coolant in the tank to the top line so it's easy to keep an eye on the level. Fingers crossed

 

[avenali312]

Just reporting back that I haven't been able to hear any coolant moving through since burping the system. Considering this fixed (for now haha).