Buyer Research

2018 Mazda Mazda6 — Should You Buy One?

Typical asking price: $14,000–$21,000. There are 3 high-severity known issues you need to know before handing over a check.

Deciding between model years? Compare the 12 Mazda Mazda6 years we've written up →

Kestrel Take

The refreshed Mazda6 — new interior, an optional 2.5 turbo, and cylinder deactivation added to the base 2.5 — and the record has one story in it: 55% of the 58 complaints are the engine, and most of those are a cracked cylinder head. It shows up as coolant or oil leaking near the exhaust manifold at 60,000 to 80,000 miles, with dealer quotes running to a new engine. Mazda extended coolant-leak coverage on the turbo to 10 years or 120,000 miles; owners of the non-turbo say they were turned away past 60,000. Two stall recalls (a PCM reflash and the low-pressure fuel pump) sit under that. This is a lovely car to drive and a real gamble on the head: buy one with the head already replaced or with the extended coverage confirmed in writing for that VIN, and confirm both recalls closed. Otherwise the 2017 is the safer year.

What we checked

Reconciled against public records, 2026-09-25

NHTSA holds 58 owner complaints for the 2018 Mazda Mazda6, and 2 recall campaigns.

A big number here usually means a lot of these were sold, not that it is a bad vehicle — popular models collect more complaints for the same rate of trouble. So the total on its own says little. What is worth reading is the shape of it. 55% of them are about one thing — the engine. That much concentration is a genuine pattern rather than background noise, and it is the first thing to check on any example you look at.

2 recall campaigns cover this model year. Recalls are repaired free, for any owner, with no time limit on most safety campaigns — but only if someone books it in. Ask the seller to show it was done, or have any dealer check the VIN; it takes them a couple of minutes and costs nothing.

Counts come from the NHTSA complaint and recall database — free, public, and worth checking yourself.

Known Issues for the 2018 Mazda Mazda6

Ranked by wallet impact. These are documented, recurring problems — not freak accidents. How we decide that.

Cracked cylinder head — coolant or oil leak at the exhaust side, sometimes a new engineHigh — wallet impact

Thirty-two engine complaints and the phrase that repeats is 'cracked cylinder head'. Owners find coolant sprayed across the engine bay or oil smoking on the exhaust manifold at 60,000 to 80,000 miles, on cars driven gently. Dealer quotes range from a head to a complete engine, one at over $11,000. Mazda issued service bulletins on the 2.5 with cylinder deactivation, and for the 2.5 turbo it extended coverage of coolant leaks at the cylinder head to 10 years or 120,000 miles for a specific VIN range; the non-turbo owners in this record say they were refused past 60,000 miles. Before buying, run the VIN past a Mazda dealer and ask in writing whether it carries any extended cylinder-head coverage. At the car, look for a sweet coolant smell, crusty pink or orange residue on the head near the exhaust, and any oil sheen on the manifold heat shield.

Repair cost (estimate): $3,000–$6,000 for a cylinder head; $8,000–$12,000 for a replacement engine at a dealer — around 69% of what this car is typically worth

Source: NHTSA complaints filed under the engine (32).

Low-pressure fuel pump impeller can crack and stall the engine (recall), and pump-flange leaksHigh — wallet impact

Recall 21V875 covers 2018 Mazda6s: the impeller in the in-tank fuel pump swells and deforms, the pump stops, and the engine dies in traffic and may not restart for hours. Parts were short for months in 2022, and owners here describe six stalls with a dealer finding nothing. Two more report fuel leaking at the top of the tank around the pump bolts — outside the recall and a fire matter. Run the VIN lookup for the recall, then get under the back seat or the car after a fill and check for a fuel smell.

Repair cost: $0 with the recall — verify it was performed; $400–$1,000 for a leaking pump flange the recall does not cover

Source: NHTSA complaints filed under the fuel system (7); 2 NHTSA recall campaigns on this model year.

PCM software error can stall the engine (recall)High — wallet impact

Recall 19V497 covers 2018–2019 Mazda6s: a software fault in the powertrain control module can shut the engine off without warning. The remedy is a free PCM reflash, done in an hour. Some of the stall reports on this year may belong to this recall rather than the fuel pump; a car with both closed on the VIN lookup takes the software half of the question off the table.

Repair cost: $0 with the recall — verify it was performed

Source: 2 NHTSA recall campaigns on this model year.

Six-speed automatic surges or drops drive; early belt tensioner failureMedium

Nine power train complaints, two of which are the cracked head filed under the wrong heading. The rest: a transmission that surged repeatedly with no warning light and no fix after several dealer visits, one sudden loss of drive with gear-ratio and shift-error codes (P0731, P0780), one shutdown with every dash light on, and a drive belt tensioner replaced under warranty before 36,000 miles. Few reports, but the loss-of-drive one is worth a hot test drive with several hard stops and pulls. Listen for a rattle from the belt side of the engine at idle.

Repair cost (estimate): $200–$600 for a belt tensioner; $3,000–$4,500 if the transmission is replaced — about 26% of what this car is typically worth

Source: NHTSA complaints filed under the transmission and drivetrain (9).

Walk-Away Red Flags

✗Sweet coolant smell or pink crust on the cylinder head near the exhaust manifold
✗Oil smoke or a burnt-oil smell after a drive, with the leak on the exhaust side
✗Low coolant in the overflow tank on a car the seller says has been serviced
✗Either stall recall still open on the NHTSA VIN lookup
✗Fuel smell around the rear seat or the tank after a fill-up

Good Signs

✓Cylinder head replaced by Mazda, with the invoice and the new-head part number
✓Written confirmation from a Mazda dealer that this VIN carries extended cylinder-head coverage
✓Recalls 19V497 and 21V875 both shown complete on the VIN lookup
✓Coolant level steady at the full mark on a stone-cold engine
✓A dry, clean exhaust manifold heat shield with the engine warm