{"nhtsa_id":10147664,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2018-11-13","date":"2015-03-01","document_id":"B121515","mfr_campaign":null,"replaces":null,"component":"ENGINE","mfr_system":null,"summary":"N55:Corrosion on Delphi Ignition Coil Outer Heat Shield. Signs of corrosion are found on an ignition coil(s) metal heat shield when replacing the spark plugs or performing an engine repair. On the N55 engine, moisture can enter the spark plug shafts due to the design of the cylinder head cover and ignition coil sealing cover. This can cause slight to moderate traces of corrosion to develop on the ignition coil metal heat shield; however, this will not have any impact on the function or performance of the ignition coil.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2015/MC-10147664-9999.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2015/MC-10147664-0001.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/10147664","components":[{"id":"engine","name":"Engine","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"BMW","model":"BMW","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":[]}