Is My Coolant low?

[JayceeP]

Was checking the oil on my 2024 Yukon XL and had a look at the coolant reservoir in the first 2 pics (Engine Coolant Surge Tank). Is this too low? It’s a long weekend here so I’ll reach out to the dealer in the am. Hitting the highway later this week so trying to get answers asap.

It was this level a couple weeks ago but I forgot to follow up on it.

The 3rd pic, Charge Air Coolant Surge Tank, does look good however. Not sure how one ties into the other. Assume the Charge tank being full is more important?

 

[Stbentoak]

I had seen this on mine maybe a couple of years ago. I filled it up above the cold mark with the appropriate coolant and it's pretty much been good ever since. There could have been a one-time reason why it got low. I wouldn't read a whole lot into it unless it's taking it down to the bottom on the regular.

 

[StephenPT]

A little bit but not alarming. You can top it off with distilled water - or buy 50/50 DexCool premix.

You want the engine coolant reservoir right at the middle seam - kind of hard to see when it's at that level, but as long as you don't see the coolant level below the seam, you're fine.

The CAC coolant level should come up a bit so it's touching the point on those two arrows.

FYI - the two coolant systems are completely independent. Engine coolant loop handles the engine and oil cooler. CAC coolant loop handles the CAC and transmission heat exchanger.

 

[JayceeP]

A little bit but not alarming. You can top it off with distilled water - or buy 50/50 DexCool premix.

You want the engine coolant reservoir right at the middle seam - kind of hard to see when it's at that level, but as long as you don't see the coolant level below the seam, you're fine.

The CAC coolant level should come up a bit so it's touching the point on those two arrows.

FYI - the two coolant systems are completely independent. Engine coolant loop handles the engine and oil cooler. CAC coolant loop handles the CAC and transmission heat exchanger.

This stuff look right? It says 50/50 pre-mixed. But also has anti-freeze?

 

[Scarey]

Great info, I assumed one was an expansion/overflow. I had no idea they’re two separate loops. I to am curious about brand/type of coolant?

Separate question, I was very surprised to see the 3.0 runs on 0-20 oil. I assume it’s different than the gasser 0-20? 0-20 diesel specific?

 

[Stbentoak]

DexosD.. many flavors available. Just as cheap as 6.2 oil.....

 

[StephenPT]

This stuff look right? It says 50/50 pre-mixed. But also has anti-freeze?

Yep - that stuff is compatible with the factory filled coolant. 50/50 means 50% distilled water and 50% ethylene glycol (aka anti-freeze).

 

[JayceeP]

Thanks guys - appreciate the help!

 

[flynfish]

Our 2024 XL (22k miles) had a coolant hose leak while my wife was on a 5hr road trip. Dealer "fixed it" and then she was on another trip and a ton of coolant came pouring out when she stopped to use the bathroom. Dealer has it again now and has replaced 2 hoses that were leaking.

If I were you, I would have them check for leaks. I'm baffled that a new vehicle could have this many issues with hoses.

 

[JayceeP]

Our 2024 XL (22k miles) had a coolant hose leak while my wife was on a 5hr road trip. Dealer "fixed it" and then she was on another trip and a ton of coolant came pouring out when she stopped to use the bathroom. Dealer has it again now and has replaced 2 hoses that were leaking.

If I were you, I would have them check for leaks. I'm baffled that a new vehicle could have this many issues with hoses.

Crazy. I have been checking the reservoir periodically and it hasn’t seemed to move at all since I posted this back in May. I just checked now and it looks the exact same.

 

[JayceeP]

Drove over 300km to PEI yesterday. Not super hot outside but trans temps seem to be fine. Mid to high 180’s F.

 

[PPK_]

I don’t think the duramex has the cooling to do very much altitude.. mine gets a lot hotter than my fords did…

 

[JayceeP]

I don’t think the duramex has the cooling to do very much altitude.. mine gets a lot hotter than my fords did…

I don’t think I’ve seen trans temps above 190. But I’m not at altitude. Sea level to 500-700ft above max. Also, summer temps are not like the south or western states. 70-80s is normal here. Into the 90’s we get heat warnings lol.

 

[StephenPT]

I don’t think I’ve seen trans temps above 190. But I’m not at altitude. Sea level to 500-700ft above max. Also, summer temps are not like the south or western states. 70-80s is normal here. Into the 90’s we get heat warnings lol.

We tow a 5K travel trailer. I've never seen over 200F. Upper 180's to low 190's while towing. Upper 170's when not towing. If I saw 225F on mine I'd start trying to figure out what's wrong (faulty thermostat, pinched line, etc.)

 

[JayceeP]

Just an update on this. Had the Yukon in for a maintenance at a different dealer than the one I bought from - oil change and tire rotation. Routine inspection etc. I asked about the coolant. They did a test and detected zero leaks. As I only had 11,000 miles on it, they thought it might have been like that at the time I took ownership and it wasn’t topped up, just like my DEF wasn’t lol. Anyway. They added some coolant and all should be fine. Sharing only for awareness in case anyone digs up this thread here’s some pics from today. Should be good to go.

 

[Fless]

Do yourself a favor and pick up some 50/50 DexCool premix, and top it off yourself when you see that it's low. Monitor it for usage.

 

[JayceeP]

Do yourself a favor and pick up some 50/50 DexCool premix, and top it off yourself when you see that it's low. Monitor it for usage.

Yeah I will going forward. It didn’t change at all from when I first posted. Now that it’s bang on the line as it should be I’ll be able to tell as well.

 

[Stbentoak]

On My 21, mine went down to the lower one 3rd in like the first year of its life. I topped it up with the appropriate stuff and never had to mess with it again for the next three years. It may have needed to burp or something but unless you have a leak coming out the bottom or it needs continual filling, I wouldn't read a whole lot into it yet.

 

[StephenPT]

On My 21, mine went down to the lower one 3rd in like the first year of its life. I topped it up with the appropriate stuff and never had to mess with it again for the next three years. It may have needed to burp or something but unless you have a leak coming out the bottom or it needs continual filling, I wouldn't read a whole lot into it yet.

Didn't you also have one of the heat exchangers replaced because it was weeping coolant? It's been awhile but I thought you had it in for service and the tech saw a small coolant leak...

 

[Stbentoak]

Didn't you also have one of the heat exchangers replaced because it was weeping coolant? It's been awhile but I thought you had it in for service and the tech saw a small coolant leak...

You are correct. On the 2021 when they had it up in the air to replace the fuel filler neck, they noticed that the oil / coolant cooler that's bolted directly to the side of the transmission Showed some weep marks on it. I believe it was leaking at a brazed joint. They replaced that. But my coolant went to the bottom sooner than that was replaced at one time, and I thought I had a serious leak. But after refilling it, it basically never went down again. May or may not be related.