Q: Engine started burning oil, what can I do?

Your truck is using excessive oil in my opinion. GMC has oil consumption ongoing issues for your year truck and most engines they equipped them with. I would recommend getting an oil consumption test to document the exact amount of oil you are using per 1000 or 2000 miles. This test would be done by your dealer and would start with fresh oil change and all oil entries tamper proofed for accuracy of test. Once test has started, you will have to bring in to have oil added and document amount of oil added and mileage driven. If dealer says it is excessive oil consumption, then a full diagnostics would have to be done to locate cause. This issue may be happening from the pistons oil control rings allowing too much oil to get past them when the piston is on its down stroke. The rings in newer style engines do not have as much tension pushing on cylinder walls as the older year engines did. This is a design to reduce friction and increase gas mileage on all newer engines. The problem is the lower tension rings can allow excessive oil to get by them and cause the oil consumption. To fix your engine, you would have to replace all the piston rings and if new style valve covers apply to your VIN number, then replace them also.