Mazda · 2012–2022
Common Mazda CX-5 problems, and how to check them
These are the 2 faults owners and garages report most often on the Mazda CX-5, from the most common down. For each one: what goes wrong, how to check it yourself, and the usual fix, so you know what you’re dealing with before you buy parts.
Fact-checked by a licensed car technician · last reviewed 28 September 2026
Problem 1
Mazda CX-5: Oil level rising: diesel in the oil after filter regenerations
What goes wrong
When the particulate filter cleans itself, extra diesel is injected; on short trips the regeneration often doesn’t finish and the diesel ends up in the sump. The oil level rises and the thinned oil wears the engine.
How to check it yourself
Check the dipstick regularly: oil above the max (or “X”) mark means dilution. Read the DPF soot load and the oil-dilution counter with a Mazda-capable tool.
The usual fix
Change the oil and filter straight away and reset the counter, update the engine software, and drive longer trips so regenerations finish. Mazda fitted revised dipsticks and software on early cars.
Signs: Check engine light, Loss of power
Fault codes: P2002, P242F
Problem 2
Mazda CX-5: Leaking injector washers: soot in the oil and a blocked oil strainer
What goes wrong
The copper washers under the injectors fail, letting combustion gas and soot into the crankcase. The soot turns the oil into sludge that can block the oil pump strainer and starve the engine of oil.
How to check it yourself
Listen for chuffing at the injectors, look for black deposits around them, and check the oil for thick black sludge. Injector over-fuelling codes (P1052-P1055) point the same way.
The usual fix
Replace the injector washers (and injectors if needed), change the oil, and have the sump and oil strainer cleaned.
Signs: Hard starting, Rough idle, Check engine light
Fault codes: P1052, P1053, P1054, P1055
General guidance, not a professional inspection. Confirm faults with measurements before buying parts, and use a qualified mechanic for brakes, steering, fuel leaks, airbags, and other safety-critical work. Terms and disclaimer