Engine coolant level in surge tank ?

[Rizop]

Hi there ! I’ve had my 22 Yukon xl denali duramax for about 7 months and love it !

I opened the engine bay today to look around and noticed that the coolant level looked a little low in the engine coolant surge tank (about an inch below the big halfway seam) . The attached pictures were taken about 4 hours after the engine was shut off .

The charge air coolant surge tank seemed to be pretty full .

Apologies as I don’t have much experience with this , does the coolant level in the first tank seem low to any of you guys given the fact that the engine has been shut off for a few hours ?

Thanks !

 

[Pro299]

Looks just like mine. I notice the full line under the hoses is at the seam, but can't tell if that's for cold or hot. I guess labelling it with a C or an H would have made it too easy for us.

 

[Fless]

That's a cold fill line.

 

[Rizop]

great info ! Given the fact that I checked the coolant level this morning and it was at the same level as in the pic before I started the car (I would assume cold ) , do you think that the fluid is at an acceptable level (below the halfway point seam)?

 

[Fless]

I think that level would be okay, but I'd top it off and keep an eye on it. Sometimes it takes a bit to purge any air in the system.

 

[StephenPT]

Here’s mine. 3.8K miles total. Looks like your engine surge tank is a tad low. Level when cold should be right at the seam of the top and bottom pieces that make the surge tank

 

[Rizop]

Here’s mine. 3.8K miles total. Looks like your engine surge tank is a tad low. Level when cold should be right at the seam of the top and bottom pieces that make the surge tank

Thanks for the pics and this super helpful ! Your charge air tank seems a little less full than mine . I don’t know much about these systems , but do the two tanks transfer coolant between them , thus the fluctuation in levels ?

I just got back home a few minutes ago and noticed that the coolant in the engine coolant tank had risen a little bit (perhaps half an inch ) , but still a half inch short of the seam .

 

[StephenPT]

Thanks for the pics and this super helpful ! Your charge air tank seems a little less full than mine . I don’t know much about these systems , but do the two tanks transfer coolant between them , thus the fluctuation in levels ?

I just got back home a few minutes ago and noticed that the coolant in the engine coolant tank had risen a little bit (perhaps half an inch ) , but still a half inch short of the seam .

Completely independent systems.

Your surge tank is a bit higher because you checked it shortly after you got home. Best to check it the next day.

 

[Stbentoak]

My main tank was a half inch from the bottom about three months ago. I filled it to within an inch of the top and just let it purge out overflow. My dealer found a leak on the transmission cooler exchange unit and so far it seems to be holding in there at about an inch above the seam.
But low coolant levels have been a theme on Sierra forums too with the 3.0….

 

[Rizop]

My main tank was a half inch from the bottom about three months ago. I filled it to within an inch of the top and just let it purge out overflow. My dealer found a leak on the transmission cooler exchange unit and so far it seems to be holding in there at about an inch above the seam.
But low coolant levels have been a theme on Sierra forums too with the 3.0….

Thanks for all the info . Looks like I’ll be scheduling an appointment to get it looked it at . I need to get the third row recall done anyways . Last thing we need is for the engine to overheat on a road trip lol