{"nhtsa_id":10005500,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2004-03-01","date":"2004-01-01","document_id":"01485","mfr_campaign":null,"replaces":null,"component":"ENGINE AND ENGINE COOLING:ENGINE","mfr_system":null,"summary":"TIMING CHAIN TENSIONER BREAKPOINTS FOR SERVICE KIT OR PRODUCTION FIX. RATTLE-TYPE NOISE COMING FROM THE ENGINE AT APPROXIMATELY 1800 TO 2200 RPMS. 4.3L LU3 L35 ENGINE. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/10005500","components":[{"id":"engine","name":"Engine","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"CHEVROLET","model":"ASTRO","year_from":2003,"year_to":2003,"match":null,"vehicle_ids":[]},{"make":"CHEVROLET","model":"BLAZER","year_from":2003,"year_to":2004,"match":"exact","vehicle_ids":["2003_chevrolet_blazer","2004_chevrolet_blazer"]},{"make":"CHEVROLET","model":"EXPRESS","year_from":2003,"year_to":2003,"match":"exact","vehicle_ids":["2003_chevrolet_express"]},{"make":"CHEVROLET","model":"S10","year_from":2003,"year_to":2004,"match":null,"vehicle_ids":[]},{"make":"CHEVROLET","model":"SILVERADO","year_from":2003,"year_to":2003,"match":"exact","vehicle_ids":["2003_chevrolet_silverado"]},{"make":"GMC","model":"SAFARI","year_from":2003,"year_to":2004,"match":"exact","vehicle_ids":["2003_gmc_safari","2004_gmc_safari"]},{"make":"GMC","model":"SAVANA","year_from":2003,"year_to":2004,"match":"exact","vehicle_ids":["2003_gmc_savana","2004_gmc_savana"]},{"make":"GMC","model":"SIERRA","year_from":2003,"year_to":2004,"match":"exact","vehicle_ids":["2003_gmc_sierra","2004_gmc_sierra"]},{"make":"GMC","model":"SONOMA","year_from":2004,"year_to":2004,"match":"exact","vehicle_ids":["2004_gmc_sonoma"]}],"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":[]}