NHTSA complaint #11741916

Owner complaint summary

My 2019 Mazda CX-5 (equipped with the 2.5L naturally aspirated SkyActiv-G engine with cylinder deactivation) has experienced a severe structural failure resulting in a cracked engine cylinder head. This casting defect allows pressurized motor oil to leak continuously from the cylinder head down onto the hot engine block and nearby exhaust components. This has led to the following severe safety risks: engine oil is leaking onto the exhaust manifold and creates an extreme risk of engine compartment fire when the vehicle is in motion; sudden loss of oil pressure or complete structural failure of the cylinder head can cause the engine to stall or seize unexpectedly without warning, completely disabling the vehicle in live traffic and creating an imminent crash hazard; and dropping oil levels and leaking fluids burning against the engine produce strong smoke and chemical odors that enter the cabin, which can cause driver distraction and severely limiting visibility if smoke escapes through the hood. We are also inhaling these odors. Mazda is fully aware of this structural engine defect and has detailed it internally under Technical Service Bulletin TSB #SA-031-21 (as well as related TSBs for oil seepage/leaks on these cylinder heads). Despite acknowledging the manufacturing flaw, Mazda has failed to issue a safety recall for this dangerous fire and stalling hazard, forcing consumers to drive unsafe vehicles or pay thousands of dollars out of pocket for a known defect. The vehicle currently has 62,317 miles. The crack and oil leak were officially diagnosed by the Carlsbad Mazda dealership service department on 5/26/26. I am requesting that the NHTSA launch a formal safety defect investigation into Mazda 2.5L cylinder head cracking to force a safety recall before this defect leads to a fatal fire or highway accident.