I have recently over the past week paid attention to my antifreeze level, the cold level of antifreeze after driving and letting it sit for 10+ hours seems to consistently decrease.....

I've checked for leaks, which I have not found any visible leaks or puddles under the truck, i've checked the oil for contamination, which there is none, i've checked the smell of the exhaust and it didn't smell sweet. (though it does smoke, but it's winter, so I can't tell if it'll smoke in summer, if it does smoke in the summer, what's that a sign of it it doesn't smell sweet?)

But between filling the overflow to around full and running the engine a few cycles a day, and checking it the next day cold the level seems to drop around an 1/2 to an inch, i've read that once you fill the overflow when cold the level in it should not change when it's cold again, but then i've read conflicting reports that it will fluctuate between max and minimum.

I have driven for 6 months with this truck as we just got it second hand, and have only recently started paying attention to the antifreeze level. i've topped it off like 4 times I think but the engine has never even came close to overheating.

What are your guys thoughts on this issue?

 

Don't fill the overflow tank.

When the engine is cold / been sitting overnight pop the rad cap off and fill er up, start engine and eventually the level will drop, keep filling as the engine sucks in more coolant. If the level doesn't drop for 2-3 minutes of running, cap it and drive.

Next day repeat this process until you can pull the cap off when the engine is cold and the rad is full to the top.

Have you checked the oil lately? is it chocolate milk?

 

^that is the process of burping the system. I might add to that, drive your front passenger tire up on a ramp, leave the driver side on the ground, so that the radiator cap is the highest point for the cooling system (helps burp air out). Then proceed with the process above. You might have air in there if the system was recently opened to air (i.e. thermostat change). If you haven't opened up the system to air, fill the radiator full, then fill the overflow to full mark and call it good. Check back in a few days and see what you have. Check again for leaks closely. A few people on here have the same problem with little bits of coolant magically disappearing. Doesn't seem to be a huge deal.

 

I would pull the alternator and take a close look at the water outlet gasket...those seem to be a problem area for the cooling system in our trucks and they like to rot away and cause coolant to seep out onto the manifold...problem is, the coolant that leaks out here never usually makes it to the ground because it is evaporated off by the hot engine

 

Oil is clear, it just seems the levels drops erratically from day to day when engine is cold, radiator is full, so is overflow, but the level just drops with no apparent signs of leakage, or blown head gasket.

I didn't elevate the passenger side today but I did take the radiator cap off and let the truck heat up, to the point the thermostat opened and coolant circulated at that time I gained like two inches of antifreeze past full, let it run for about 15 minutes while watching the level, it stayed within the small circle inside of the unit, the whole thing wasnt full, just the inner circle, I squeezed the upper and lower hoses trying to see if there might of been any air, but only one or two small bubbles formed.

Let it cool for an hour went to work a block away, truck didn't have time to warm up, level dropped about an inch above full, four hours later it was even lower in the overflow, the level it was before the first circulation, but there is no antifreeze on ground, in oil, burning out the tailpipe, or any signs or smells whatsoever under the hood, maybe I have a really bad air bubble in there somewhere that's never came out after my flush in November.

I have never had any overheating issues tho.