Like cores are to be returned within 30 days from purchase date (or sooner on specific cores). Manufacturer’s require cores be returned as removed from engine (intact, no disassembled cores accepted), including data tag (ID label) and identifying core part number. Missing or damaged parts on cores, may result in reduced or no core credit at the manufacturer’s discretion. All core credit is conditional and may be withdrawn if the core fails inspection by vendor, OEM or manufacturer. Cores may be returned to sender if found not in compliance with manufacturer specs or may result in a 25% core reduction fee. Our Customer Service Department will gladly assist you with any questions you may have regarding manufacturer acceptable cores.