{"nhtsa_id":620289,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2001-07-24","date":"2001-03-01","document_id":"13987","mfr_campaign":null,"replaces":null,"component":"POWER TRAIN:AUTOMATIC TRANSMISSION; ENGINE AND ENGINE COOLING:ENGINE:GASOLINE","mfr_system":null,"summary":"SOME VEHICLES EQUIPPED WITH 3.8L ENGINES MAY EXHIBIT ENGINE SPARK KNOCK ON HEAVY ACCELERATION WITH 87 OCTANE FUEL. HOT WEATHER AND LOWER OCTAINE FUEL CAN CONTRIBUTE TO THE CAUSE OF A SLIGHT KNOCK ON HEAVY ACCELERATION. THOUGH NO DAMAGE TO THE ENGINE WILL OCCUR, SOME CUSTOMERS REPORT THAT THE SOUND IS NOT DESIRABLE. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/620289","components":[{"id":"engine","name":"Engine","parent":null},{"id":"powertrain","name":"Transmission and driveline","parent":null},{"id":"automatic-transmission","name":"Automatic transmission","parent":"powertrain"}],"codes":[],"topics":[],"vehicles":[{"make":"FORD","model":"MUSTANG","year_from":1999,"year_to":2000,"match":"exact","vehicle_ids":["1999_ford_mustang","2000_ford_mustang"]},{"make":"NISSAN DIESEL","model":"UD TRUCK","year_from":null,"year_to":null,"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":[]}