Symptoms

Oil leak, oil consumption or rising oil level

What causes it depends on the engine. 25 documented failures on 15 engines list this among their signs. Pick your engine for the causes ranked, how to tell them apart and the usual fix.

7.3 Power Stroke (1994.5-2003) 2 known causes, most widespread: Injector o-ring failure 6.0 Power Stroke (2003-2007) 1 known cause: Engine oil cooler clogging / failure 6.4 Power Stroke (2008-2010) 4 known causes, most widespread: Compound turbo bearing-seal leaks 6.7 Power Stroke (2011-present) 2 known causes, most widespread: Piezo injector wear and fuel dilution of engine oil 3.0 Power Stroke (2018-2021) 1 known cause: DPF regeneration duty and oil dilution 6.7 Cummins 2007-2018 2 known causes, most widespread: Injector 'chuffing' / seal blow-by Ram 1500 EcoDiesel (2014-2019) 1 known cause: Oil cooler oil/coolant cross-contamination Duramax LB7-LMM (2001-2010) 1 known cause: LB7 injector failures (the defining repair of the generation) Duramax LML (2011-2016) 1 known cause: Piezo injector failures / replacement economics (LML) 3.2 Power Stroke (Transit) 3 known causes, most widespread: Engine oil leaks / crankcase ventilation hose Sprinter 3.0 V6 (OM642) 1 known cause: Oil cooler stack seal leak (the signature OM642 repair) 6.2 Boss (gas) 1 known cause: Oil consumption (owner reports) 3.5 EcoBoost (gas) 3 known causes, most widespread: Internal water pump: coolant loss and coolant-into-oil risk ProMaster 3.6 (gas) 1 known cause: Plastic oil filter/coolant housing-adapter leak (the signature Pentastar leak) GM 6.0 L96 (gas) 1 known cause: Oil consumption at high mileage (Gen IV theme)

Built from the failure-mode records on this site: a failure is listed when its own symptom list describes this sign. Engines not shown have no documented failure with it in our records. How we tier and source facts.