US Patent 7802427 System and method for monitoring boost leak

An engine system is disclosed that monitors for boost leak. The system has an engine, a compressor located upstream of the engine, at least one auxiliary flow device located downstream of the engine, and a computing system operable to determine an estimated value corresponding to a flow of fluid through the compressor. The estimated value takes into account a flow of fluid from the compressor toward the at least one auxiliary flow device distinct from a flow from the compressor toward the engine.