CriticalCommonEngine

Mazda Mazda6: SkyActiv-D 2.2 oil dilution and DPF problems on short-trip cars

SkyActiv-D 2.2 oil dilution and DPF problems on short-trip cars is a common engine fault on the Mazda Mazda6 on the 2012 onward cars, and we rate it critical. Putting it right costs $400 to $8,000 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 48 documented faults on the Mazda Mazda6.

Vehicle: Mazda Mazda6
Engine: 2.2L
Years: 2012 onward
Fuel: diesel
System: Engine

This page covers the Mazda Mazda6 as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Mazda Mazda6 faults48 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the Diesel particulate filter yet. We would rather show none than show a picture of a different part.

What goes wrong

The GJ/GL's SkyActiv-D 2.2 is refined and economical on the open road, but city-driven cars interrupt DPF regenerations, diesel washes into the sump and the oil level climbs past maximum — Mazda's dipstick even has an 'X' overfill mark for exactly this. Chronic dilution thins the oil and can take out the engine's bottom end or turbo. Mazda Australia handled numerous complaints and extended goodwill on some engines; buying one without open-road history and immaculate servicing is a gamble.

What you would notice

Oil level rising between services / oil above the dipstick X mark
Frequent DPF regenerations — raised idle, hot smell, fans running after shutdown
DPF or check-engine warning lights
White/blue smoke and diesel smell in the oil

How to check it

Where to look. Engine sump and dipstick under the bonnet; DPF in the exhaust under the car

Check the dipstick — the level must be between min and max and the oil should not smell of diesel.
Ask directly what the car is used for; a motorway commuter is fine, a school-run car is not.
Look for invoices showing oil changes every 10,000 km or sooner and any DPF replacement or Mazda goodwill work.

Parts involved: Diesel particulate filter.

What it costs to put right

$400 to $8,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Has the oil level ever risen on its own?”
“Has the DPF ever been replaced or forced-regenerated?”
“What percentage of the car's use is open-road?”

Now check the Mazda Mazda6 you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

CarsGuide and CarExpert AU articles on Mazda SkyActiv-D oil dilution complaints
mazda6club.com and mazdas247 SkyActiv-D oil dilution threads
Mazda owner's manual dipstick X-mark guidance for diesel oil rise

Mazda Mazda6 buyer questions

Is skyactiv-d 2.2 oil dilution and dpf problems on short-trip cars serious on a Mazda Mazda6?

We rate it critical and common on the Mazda Mazda6. The GJ/GL's SkyActiv-D 2.2 is refined and economical on the open road, but city-driven cars interrupt DPF regenerations, diesel washes into the sump and the oil level climbs past maximum — Mazda's dipstick even has an 'X' overfill mark for exactly this. Chronic dilution thins the oil and can take out the engine's bottom end or turbo. Mazda Australia handled numerous complaints and extended goodwill on some engines; buying one without open-road history and immaculate servicing is a gamble.

How much does it cost to fix on a Mazda Mazda6?

$400 to $8,000 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Mazda Mazda6 years are affected?

Our research records this fault on the 2012 onward Mazda Mazda6. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Check the dipstick — the level must be between min and max and the oil should not smell of diesel. Ask directly what the car is used for; a motorway commuter is fine, a school-run car is not. Look for invoices showing oil changes every 10,000 km or sooner and any DPF replacement or Mazda goodwill work. Look here: Engine sump and dipstick under the bonnet; DPF in the exhaust under the car