* Valve stem seals: These seals wear out over time, allowing oil to leak past the valves and into the combustion chamber, where it's burned. This is a common cause of oil consumption in this engine.
* Piston rings: Worn piston rings can also allow oil to seep past into the combustion chamber.
* PCV system: Problems with the positive crankcase ventilation (PCV) system can lead to excessive oil buildup and consumption.
* Overall wear and tear: Like any engine, higher mileage naturally leads to increased wear and tear, increasing the chances of oil leaks and consumption.
Therefore, the answer is not a simple yes or no. Some 1998 Silverado 5.7L engines may burn very little oil, while others might burn a significant amount. The amount of oil consumption depends heavily on the vehicle's maintenance history, driving habits, and overall condition. A small amount of oil consumption (a quart every 1000-2000 miles) might be considered acceptable for a higher-mileage engine, but excessive consumption (a quart every few hundred miles) indicates a problem that needs attention.
