I've noticed that my 09 Yukon xl SLE 5.3 eats up a lot of coolant. It guzzles it up while driving at normal temperatures but dumps it back into the reservoir when it starts to cool off after being turned off. There is no overheating issue, visible leaks, nor smell. It smoked a bit yesterday from the engine bay but, that might have simply been due to the cold weather since it all immediately disappeared once I opened the hood. I wasn't able to get it to smoke up after actively looking for it. There's also no milky oil. I did recently get a cam with a dod delete into it after fixing a lifter ticking if that matters. Is this an issue or am I overthinking it?