Coolant level is low

[Jeremy Hathaway]

I noticed yesterday my coolant level was about an inch low in the bottle. I added to the full cold mark and for two days it hasn’t changed. But I also noticed these white specks in my tailpipe. Any ideas?

[CadillacLuke24]

That doesn't look good. DexCool dries white. May be time to do a block test. 

[Sierra Dan]

What year is your truck?

If you have a '14 thru early '16 truck they fell victim to cycling thermostat causing stress cracks in the radiator

where the plastic sides meet the aluminum body. Outcome is a slow loss of coolant.

So check that also.

[midwestdenaliguy]

Do you have a rough start when it's cold or sitting a while? If so, the heads on some of the engines form pinhole sized leaks and coolant leaks into the intake/piston. It gets burned off through the exhaust. When the leak gets bad enough it causes a rough start and white smoke out of your tailpipe when you first turn it on after sitting. Can throw code P050D. Also throws misfire codes. Hopefully that's not the case for you...