The Mazda 6 GJ is a genuinely brilliant car to drive — sharper than a Passat, better looking than a Mondeo and with an interior that punches well above its class. But the 2.2d engine fitted to 2012–2015 models carries some well-documented and potentially serious issues that every buyer needs to understand before parting with money.
Overview
The third-generation Mazda 6 launched in Ireland in 2013 and was immediately praised for its driving dynamics and premium feel. It appealed to drivers who wanted something more interesting than the default German options. At its best, the 2.2 SkyActiv-D is an impressive engine. At its worst, it is an expensive and frustrating ownership experience.
This review covers the 2.2-litre SkyActiv-D diesel only. The 2.0-litre petrol Mazda 6 of the same generation is a fundamentally different ownership proposition — none of the issues covered here apply to it. If you are looking at a petrol example, it is widely regarded as one of the more reliable used buys in this class and warrants a straightforward inspection rather than the caution required for the diesel.
Engine & Gearbox
The 2.2-litre SkyActiv-D diesel came in 150hp and 175hp outputs, with most Irish examples paired with a 6-speed manual. Unlike most diesels of the era, the SkyActiv-D uses an unusually low compression ratio of 14.0:1 — Mazda's approach to reducing NOx emissions and improving thermal efficiency. It is clever engineering that works well when the engine is properly maintained, and becomes a serious liability when it is not.
Known Faults — Read This Before You Buy
Leaking injector seals and blocked oil pickup strainer is the most serious risk on this engine — and the one responsible for the most catastrophic failures. The copper injector washers fail over time, allowing combustion gases into the engine block. This carbonises the oil into thick sludge which settles in the sump and blocks the fine mesh of the oil pickup strainer. The oil pump is starved of supply, oil pressure drops suddenly, and the result is scored camshafts and total engine seizure. This is not a recoverable failure. Any pre-2015 example without documented injector seal work is carrying this risk.
Oil dilution is the warning sign that precedes the above. Interrupted DPF regeneration cycles — common on cars used mainly for short urban journeys — allow unburnt diesel to mix with the engine oil. The oil level rises and the oil thins. Every SkyActiv-D dipstick has a third mark: an X stamped above the maximum line. If the oil level has reached the X mark, the oil is dangerously diluted. This is the first check on any viewing.
Exhaust camshaft wear affected 2012–2014 models specifically. A problem with the metal hardening process left camshaft lobes insufficiently hardened — they wear prematurely, sending metal particles through the oil system and into the turbocharger. Listen for ticking from the top end and ask specifically about camshaft inspection history on any early example.
Carbon buildup in the intake manifold is a known consequence of the SkyActiv-D design. Heavy deposits restrict airflow, cause rough running, loss of power and increased fuel consumption. A carbon clean is a specialist job and an additional cost to factor in.
Turbo failure is also recorded on earlier units, often as a downstream consequence of oil system problems. Listen for any whirring or whistling from the turbo on startup and at various rev ranges during a test drive.
What to Check on Inspection
Pull the dipstick immediately. The SkyActiv-D dipstick has three marks — minimum, maximum, and an X above the maximum. If the oil level is at or above the X mark, the oil is dangerously diluted. Walk away. This is non-negotiable.
Ask for all service records and look specifically for evidence of injector seal replacement, carbon clean, or oil strainer service. Any seller of a pre-2015 example who cannot produce documentation is asking you to absorb an unknown and potentially very expensive risk.
On 2012–2014 models, ask specifically about camshaft inspection. Premature exhaust camshaft lobe wear is well documented on this period of production and the consequences for the turbo and oil system are significant.
On the test drive, listen carefully to the top end and turbo. Any ticking, whirring or hesitation under load warrants investigation by a specialist before purchase.
"Pull the dipstick before you do anything else. If the oil is at the X mark, the conversation is over."
NCT Watch Points
Front suspension arm bushings and brake disc warping are the most common NCT failure points on this model. The bushings are worth inspecting carefully — replacement is not hugely expensive but is a negotiation point if they are showing wear. On pre-facelift models the rear handbrake mechanism can bind — worth checking for even pad wear across the rear axle.
Running Costs
Road tax is approximately €190–€200 per year. Real-world fuel economy is around 48–52 MPG on a mixed cycle. The bigger concern on running costs is the potential for significant engine-related expenditure on a car that has not been properly maintained — injector seal work, carbon cleaning and camshaft inspection are not cheap jobs.
What to Pay in Ireland
Prices range from €5,500 to €9,000. The fact that prices sit below equivalent Passats or Mondeos of similar age directly reflects the engine reputation. A well-documented example with evidence of injector seal work, carbon cleaning and no oil dilution history is worth paying toward the top of that range.
Verdict
Approach with caution. The Mazda 6 2.2d is a car we want to recommend because everything else about it is excellent. But the pre-2015 engine issues are too well documented and too serious to ignore. The injector seal and oil strainer failure mode is catastrophic when it occurs — there is no partial repair, only an engine replacement. Without a full, transparent service history that specifically addresses these issues, walk away. There are safer choices in this price bracket.
Frequently Asked Questions
No — this review covers the 2.2d diesel only. The 2.0 petrol Mazda 6 of the same era has none of the oil dilution, injector seal or camshaft issues described here. It is generally considered a reliable used buy and does not require the same level of caution on inspection.
Interrupted DPF regeneration cycles allow unburnt diesel to mix with the engine oil, causing the oil level to rise. Every SkyActiv-D dipstick has a third mark — an X stamped above the maximum line. If the oil has reached the X mark, the oil is dangerously thinned and the engine is at serious risk. Check the dipstick before anything else on any viewing.
Leaking injector copper washers allow combustion gases into the engine block, carbonising the oil into thick sludge. This sludge blocks the oil pickup strainer in the sump, starving the engine of oil pressure and causing catastrophic seizure. It is the failure mode responsible for the most serious and expensive engine damage on this generation.
Approach with caution. Avoid any example without documented engine work — injector seal replacement, carbon clean or confirmed oil strainer service. The pre-2015 engine issues are well documented and the risks are significant without a full service history.
Between €5,500 and €9,000. Prices sit below equivalent Passats or Mondeos of similar age because of the engine reputation. A well-documented example with evidence of remedial work is worth paying toward the top of that range.
