Engine Coolant Level Dropping

Hey everyone,

I have a 2018 Tahoe, and about a year ago my coolant level was almost gone. I took it to the dealer, and they said it was unusual for it to go down as much as it had with such low miles (25k) on the car, however, they said no leaks were found. They filled me back up, and I went on my way.

Today, a year later, the coolant is seemingly low again. I’ve attached a picture of where it is after only about 10k miles.

I’m no mechanic, but for those who know more than I do, is it normal for coolant levels to drop this much? This is my first Chevy, and I’ve just never had to deal with coolant levels dropping in other cars, even after 10 years of ownership.

I appreciate any insight that can be provided.

I have a 15 suburban and was running into the same issues. I found the issue to be the factory radiator, replaced it with a ebay special radiator (all aluminum). Found that one to be leaking through the welds after 5k miles. Bought a mishimoto radiator, their racing thermostat and replaced the coolant reserve tank. Drove it yesterday to work, truck temp did not get over 200 at all. Doing 90mph for 30 miles one way.

That's a closed system. Should hardly drop at all unless there is a leak somewhere. Get after that dealer while there's a warranty. (powertrain cover this?)

sspearsau said:

Hey everyone,

I have a 2018 Tahoe, and about a year ago my coolant level was almost gone. I took it to the dealer, and they said it was unusual for it to go down as much as it had with such low miles (25k) on the car, however, they said no leaks were found. They filled me back up, and I went on my way.

Today, a year later, the coolant is seemingly low again. I’ve attached a picture of where it is after only about 10k miles.

I’m no mechanic, but for those who know more than I do, is it normal for coolant levels to drop this much? This is my first Chevy, and I’ve just never had to deal with coolant levels dropping in other cars, even after 10 years of ownership.

I appreciate any insight that can be provided.

Click to expand...

check the big hoses connecting to the engine..

Update:

I took my car back to the dealer who originally looked into this issue because the coolant has continued to leak. They struggle to find any leaks. Claim to have done a pressure test, which held pressure. Then I received this: “This is normal. Owner to add coolant in between oil change intervals.”

I pushed back on this saying it’s not normal. As a compromise, they added dye to the system and want to look at it in 1,000 miles.

Anyone else experience this?

Not normal. If you are under warranty make them fix it.

it's a slow leak which means you might have to just find it yourself, sometimes slow leaks like to hide in not easily found places usually some where around the radiator including behind the electric fans where you can't see or under the water pump. really could be anywhere.
i had one once that only leaked after it was parked and sitting and it would spit a pin ***** sized spritz out of the middle of a radiator hose and stop, wouldn't leak a drop while running i only found it by accident.
you could try putting some dry cardboard under the front end area after you get home from the daily running around and then check it in the morning for a wet spot and look up from there. a old tv box or something will work you want to cover the whole front under the bumper/radiator and engine compartment.

Any updates on this?

I was unable to find anything myself, but I do not claim to be a coolant leak detecting expert. Clearly the dealership isn’t either.

They wanted me to drive 1,000 miles before I return so they can see if the coolant has dropped and if it has, where the dye is detected. More to come…

Seen a stain at the water pump weep hole? Am assuming no mixture with the oil and no milky deposits on dipstick and under oil fill cap? How does the transmission fluid look? Hopefully dye pinpoints it.