Engine Coolant Level Dropping

[tom3]

I've had leaks that only leaked when warming up, cold or hot it didn't leak. One was the plastic tank on the side of the radiator. Another was the coolant control valve on my third gen. Didn't see a big drop in the coolant tank but could sure smell it at times.

 

[Doubeleive]

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?

you can find it, you just need a flashlight and get under the vehicle and look up.
if there are no drops on the ground or on cardboard then focus on the radiator because air blow by will dry it out if the leak is slow enough

 

[mrathell]

I had a mysterious coolant leak on my 2015 Tahoe. I originally noticed my coolant level in the overflow tank was low, so I would top it off, only to find it was low again a few days later. I never saw coolant on the ground.

After a couple of months I finally started seeing coolant on the floor on the passenger side. After climbing under the Tahoe to take a visual inspection, I noticed coolant on the lower radiator hose. I checked the radiator to see if coolant was possibly leaking from there and traveling along the hose but that didn't appear to be the case. So I decided to replace to the lower coolant hose. The next day, coolant was on the floor in the same location. After further investigation I found the source of the leak. The leak was coming from the overflow tank. I originally thought there was a leak in the overflow tank, but actually it was leaking at the point where the radiator hose connects to the overflow tank. The hose clamp wasn't doing its job. So I purchased the worm gear style camp and installed it. The leak has never returned. I actually put two worm gear clamps on the hose for safe measures.

I believe it was difficult to find the leak in the beginning was because it was a small leak in the beginning and the fluid was only escaping while driving. So the fluid just blew away with the wind, not leaving any trace of a leak other than less fluid in the overflow tank.

 

[B-train]

Slow coolant leaks can be a *****. All good info so far on how to track it down. I would also add to look for areas that seem to have a white-ish crust by them. As coolant escapes and evaporates, it will leave other constituents behind that dry out.

 

[Thrust]

I had a mysterious coolant leak on my 2015 Tahoe. I originally noticed my coolant level in the overflow tank was low, so I would top it off, only to find it was low again a few days later. I never saw coolant on the ground.

After a couple of months I finally started seeing coolant on the floor on the passenger side. After climbing under the Tahoe to take a visual inspection, I noticed coolant on the lower radiator hose. I checked the radiator to see if coolant was possibly leaking from there and traveling along the hose but that didn't appear to be the case. So I decided to replace to the lower coolant hose. The next day, coolant was on the floor in the same location. After further investigation I found the source of the leak. The leak was coming from the overflow tank. I originally thought there was a leak in the overflow tank, but actually it was leaking at the point where the radiator hose connects to the overflow tank. The hose clamp wasn't doing its job. So I purchased the worm gear style camp and installed it. The leak has never returned. I actually put two worm gear clamps on the hose for safe measures.

I believe it was difficult to find the leak in the beginning was because it was a small leak in the beginning and the fluid was only escaping while driving. So the fluid just blew away with the wind, not leaving any trace of a leak other than less fluid in the overflow tank.

That's good info. I need to take a look at mine as I have a similar issue of a slow leak somewhere.

 

[kadrovik]

look at the upper corner of the radiator from the side of the air filter, it usually breaks there, near the tank

 

[topaq]

? blown head gasket?

 

[NardDog]

I had a leak last year and used the UV dye and flashlight. Found it on the two hoses that lead into the pump