2018 Mazda MAZDA6 engine problems

Filed Nov 3, 2026 · Engine · ID

Cracker cylinder head at only 68,000 miles on it. No warning came on, only reason we knew it started was oil leaking really bad

Filed Oct 29, 2026 · Engine · TN

I'm having an issue getting the recall serviced. Apparently, because the car's VIN number traces it's origin to [XXX], Mazda USA is unable to confirm the recall notice and the local dealership (Norcross Mazda) couldn't confirm it either when I tried to book an appointment. Mazda USA and the local Mazda sites both show the open recall on the customer end, but not on the corporate end for some reason. I spoke with a rep at Mazda USA and was told to reach out to Mazda XXX[XXX], but the service rep in [XXX] told me that the vehicle would have to be there for them to do anything. I'm in [XXX]. I've had this car for about two weeks and didn't think it would be this complicated to get this done. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Aug 7, 2026 · Engine · VA

The car only has 70k miles on it. The engine started smoking under the hood. Immediately stopped to look. There was oil leaking but I could not see from where. I took it across the street to the Toyota dealership and had them look at it. They explained to me that there was a crack in the cylinder head and oil was leaking everywhere. Potentially causing a fire or even an explosion. The old was leaking all over the exhaust manifold and engine. I had my 2 toddlers in the car not long before this happened. This is extremely unacceptable. Currently Mazda is saying it will be 7200 to replace the engine and that cost is on me. I think that is absolutely absurd being there are only 70k miles on the car and I bought it brand new. I also kept up with all of the required maintenance.

Filed Apr 30, 2026 · Engine · CA

Crack in Cylinder Head of engine. Mazda has been sued about this and have issued recalls on turbo engines, but not on non turbo ones though its the same systemic design issue with these engines. Wants me to pay 5-7k out of pocket.

Filed Apr 22, 2026 · Engine · NJ

My cylinder head is leaking coolant. There is a well known and well documented issue with these cylinder heads cracking due to poor casting. This has become such a big issue that Mazda has even recalled the cylinder heads, BUT, only if the engine is equipped with Turbo. However, this issue is becoming enormous even for non turbo owners and is a huge safety issue as it can lead to overheating, stalling, and further damage to other components. I feel very strongly that it is time for Mazda to take some responsibility and extend the cylinder head recall to the non turbo engines.

Filed Apr 7, 2026 · Engine · CA

Car had a coolant leak due to cracked cylinder head that was defective from the factory it was fixed but now the car has engine problems again. Don’t want to keep having these issues in the future

Filed Feb 22, 2026 · Engine · PA

Per Mazda inspection, the back side of cylinder head #3 has an oil leak which is leaking onto the exhaust manifold. This creates a direct fire hazard as Mazda said they highly recommend not driving it for that reason. The Mazda dealership inspected and confirmed the issue, it in February 2026, with only 74,000 miles on the vehicle.

Filed Jan 7, 2026 · Engine, Transmission · SC

I recently discovered a significant oil leak near the exhaust manifold of my 2018 Mazda 6 (2.5L NA), which has resulted in visible smoke and a burning oil odor. Upon taking the vehicle to the nearest Mazda dealership for a diagnosis, the service department informed me that the vehicle has suffered a cracked cylinder head. An active oil drip is visible behind the engine near the exhaust manifold immediately upon starting the car; consequently, the engine is leaking oil directly onto the exhaust components. This condition not only renders the vehicle inoperable but also presents a significant safety and fire hazard. At the time of this writing, my vehicle has only 46,996 miles and has been meticulously maintained. This mileage is well under the 60,000-mile powertrain threshold and represents a premature failure of a major internal engine component. There are numerous reports on Mazda owner forums describing this identical issue occurring in Mazda 6, CX-5, and CX-9 models. Some owners have even reported instances of minor fires or active burning under the hood due to oil contacting hot engine components. Mazda released Technical Service Bulletin TSB #MC-10241612-0001 (SA-037-23), which includes a redesigned cylinder head for 2018–2020 Mazda 6, 2019 CX-5, and 2016–2020 CX-9 models, demonstrating Mazda’s awareness of this design flaw. While the TSB currently only specifies the 2.5L Turbo engines and not the naturally aspirated variants, there is substantial evidence that this is a widespread defect across these model years, unrelated to owner misuse or vehicle mileage. Mazda should take full responsibility by issuing a formal recall or providing an extended warranty to cover naturally aspirated engines, thereby addressing this problem and preventing further safety risks.

Filed Oct 17, 2025 · Engine · OH

Cracked cylinder head causing oil leak and possible coolant leak. This is a known issue with this year and model. Mazda is trying to suggest the issue is only for the turbo engine, but the non-turbo engine is also defective, per countless reports online. I have a video from the service technician from the mazda dealership, but it is too big to upload.

Filed May 9, 2025 · Engine · GA

Bought used with 47k miles. Two weeks later, took it to my mechanic for an inspection, they found a massive oil leak on the back of the motor. Took it back to the dealership and they diagnosed it as a cracked cylinder head, for which there is a known TSB and warranty extension. Unfortunately, the warranty extension only covers a coolant leak from the cracked cylinder head, not an oil leak. Thankfully, the dealership took care of me but had they not, I was looking at a $7k+ repair on a car I had owned for 2 weeks. In the TSB, Mazda acknowledges that there were both design and manufacturing flaws for the affected model years. In acknowledging the issue, they should have issued a recall for affected vehicles, not a simple warranty extension