{"nhtsa_id":619382,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2001-05-24","date":"2001-03-01","document_id":"010604021","mfr_campaign":null,"replaces":null,"component":"ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:GAS RECIRCULATION VALVE (EGR VALVE)","mfr_system":null,"summary":"SOME W SERIES MEDIUM DUTY TILT CAB MODELS MAY EXPERIENCE PCV SYSTEM FREEZE-UP WHEN OPERATED IN EXTREMELY COLD WEATHER CONDITIONS, CAUSING THE ENGINE REAR MAIN SEAL TO LEAK. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/619382","components":[{"id":"engine","name":"Engine","parent":null},{"id":"exhaust-emissions","name":"Exhaust and emissions","parent":null},{"id":"egr-valve","name":"EGR valve","parent":"exhaust-emissions"}],"codes":[],"topics":[],"vehicles":[{"make":"CHEVROLET","model":"MEDIUM DUTY","year_from":1999,"year_to":2001,"match":null,"vehicle_ids":[]},{"make":"GMC","model":"MEDIUM DUTY","year_from":1999,"year_to":2001,"match":null,"vehicle_ids":[]}],"as_of":"2026-10-19","note":"A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.","attribution":[]}