[Tyrolblue67]

Hi,
Perhaps some of you cooling system experts can help by educating me?
I have a new 2019 ZL1 with 138 miles on it.
I checked the coolant tanks on my new vehicle.
The top tank seemed full although there was a slight amount of air along the top of the tank. I opened the fill cap and the coolant was at the bottom of the filler neck. There is a line on the side of the upper tank that says "Full Cold" (see photo below). The cold coolant level is on this line in my car. Curious to know why I see some photos of cars with no air pocket in the upper tank?
The lower tank was completely dry. I went to the auto parts store and purchased a gallon of 50/50 mix GM approved Dexol coolant and filled the lower tank 1/3 full as per the owners manual.
When the car warms up the upper tank coolant level rises slightly about 1/8 inch (see photo below) (still some air in the upper tank). The lower tank rises about 3/4 of an inch.
Is this normal?
Obviously my car is still under warranty. I just want to know if this is an issue.
If it is an issue, I would like to become better educated in the cooling system on our cars before discussing it with the dealership service department.
I'm planning on taking my car in for the complimentary oil change at 1,000 miles.
If needed, I can take the car in sooner if this is indeed an issue with my cooling system.
The car runs normal temperatures with no overheating whatsoever during the few miles that I've driven the car so far. I have yet to drive the car aggressively because I am still in the cars "break-in" phase. The car was brought to operating temps during idling on the driveway. I haven't driven the car since filling the lower tank to the proper level.
Thanks in advance for any information on the subject,

Regards,
Tyrolblue67

COOLING SYSTEM COLD




COOLING SYSTEM HOT (About 1/8 inch higher than when cold)

[Mosaic6SS]

It’s normal to loose some fluid through evaporation/seepage but not usually enough to empty the lower tank. The upper part is under pressure when hot so depending on how hot or warm if you remove the cap and release the pressure the level will rise. That is the point of the cold fill lines on each tank. This helps leave enough room for thermal expansion and to keep you from burning yourself, you are advised in your manual to only add coolant when cold. As far as the pictures you may be seeing pictures of hot engines (fluid expanded) or overfilled. When I first got my car it was half low on the bottom tank with 11k miles. But since I filled it to the proper level it’s been good. So I would wait until the car is cool or ambient temp and fill both tanks to the cold line.

[Ryephile]

The Camaro uses a combination degas/expansion tank plus a recovery/reservoir tank. The upper one that's always nearly full is the expansion tank, the lower one is the reservoir tank. The small tube on the aft of the assembly going to the reservoir is where coolant should be added, not by removing the pressure cap on the expansion tank.

Here's an explanation of what both do: http://blog.cantonracingproducts.com...on_vs_recovery

[Mosaic6SS]

Originally Posted by Ryephile

The Camaro uses a combination degas/expansion tank plus a recovery/reservoir tank. The upper one that's always nearly full is the expansion tank, the lower one is the reservoir tank. The small tube on the aft of the assembly going to the reservoir is where coolant should be added, not by removing the pressure cap on the expansion tank.

Here's an explanation of what both do: http://blog.cantonracingproducts.com...on_vs_recovery

⬆️This is wrong. ⬆️

Fill both surge tank and overflow tank when cold if it needs refilling.

[Ryephile]

That is assuming the expansion tank is low, as it states in the manual you quoted.

OP clearly showed his degas tank is full, but his reservoir was empty. Therefore, leave the pressure cap alone and top off the reservoir.

[Mosaic6SS]

Originally Posted by Ryephile

The Camaro uses a combination degas/expansion tank plus a recovery/reservoir tank. The upper one that's always nearly full is the expansion tank, the lower one is the reservoir tank. The small tube on the aft of the assembly going to the reservoir is where coolant should be added, assuming the expansion tank is full, andnot by removing the pressure cap on the expansion tank.

Here's an explanation of what both do: http://blog.cantonracingproducts.com...on_vs_recovery

No worries buddy I fixed it for ya!

[Ryephile]

Thanks, buddy.

Your interpretation of the Owners Manual assumes something is wrong with the pressure-side of the cooling system. You should update your post to say so. My interpretation was assuming nominal operation.

[Mosaic6SS]

Originally Posted by Ryephile

Thanks, buddy.

Your interpretation of the Owners Manual assumes something is wrong with the pressure-side of the cooling system. You should update your post to say so. My interpretation was assuming nominal operation.

Wha what? No my statement is not an interpretation it’s pretty much spot on. No need to update my post. I think u just failed to understand how the system really works.

[Ryephile]

Originally Posted by Mosaic6SS

It’s normal to loose some fluid through evaporation/seepage but not usually enough to empty the lower tank....

Here's your assumption where you're claiming coolant loss is "normal".

[Mosaic6SS]

Originally Posted by Ryephile

Here's your assumption where you're claiming coolant loss is "normal".

You are wrong again. Some coolant loss due to evaporation and seepage is normal. I have repaired many coolant systems for various issues and know this to be fact and this is also apart of many manufacturers TSB’s for normal conditions. Don’t be a troll pretending to know something it’s ok to be wrong but to right fight being wrong is pretty sad.