2018 Mazda MAZDA6 engine problems
31 owner complaints filed with NHTSA name the engine on the 2018 Mazda MAZDA6 — 56% of all complaints for this model year.
What owners report
“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 30, 2026
“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…”
filed Apr 22, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Related service bulletins
This Service Alert supersedes the previously issued M-Tip(s) listed below. The changes are noted in Red text. MT-002/19 09/30/19 and 12/19/19 DESCRIPTION If an engine assembly is replaced after a catastrophic internal…
SA-026-26 · Service Bulletin/Repair Instructions · issued Apr 16, 2026This Service Alert supersedes the previously issued SA(s) and TSB(s) listed below: The changes are noted in Red. SA-035/24 05/31/24 DESCRIPTION There is a concern that some water pumps are being replaced that are not…
SA-014-26 · Service Bulletin/Repair Instructions · issued Mar 11, 2026Subject: TSB 01-001/26 Warranty and Parts Kit Update INCLUDES: Warranty Extension Program - Special Service Program (SSP) D8 Check Engine Light ON with DTC P0126:00, 2018-2025 CX-5, 2019-2023 Mazda3, 2019-2022 CX-3…
SSPD8 Repair d · Warranty Program/Extension · issued Mar 5, 2026Subject: TSB 01-001/26 Warranty and Parts Kit Update INCLUDES: Warranty Extension Program - Special Service Program (SSP) D8 Check Engine Light ON with DTC P0126:00, 2018-2025 CX-5, 2019-2023 Mazda3, 2019-2022 CX-3…
SSPD8 Dlr Ltr a · Warranty Program/Extension · issued Mar 5, 2026Some customers may experience a check engine light ON with DTC P0126:00 (Thermostat stuck open) and one or more of the following symptoms: Engine takes longer to warm up. Engine temperature gauge fluctuates. Low coolant…
01-001-26b · Service Bulletin/Repair Instructions · issued Mar 4, 2026
Engine problems in other MAZDA6 years
| Year | Reports | Share |
|---|---|---|
| 2017 MAZDA6 | 4 | 7% |
| 2016 MAZDA6 | 7 | 9% |
| 2015 MAZDA6 | 4 | 7% |
| 2014 MAZDA6 | 15 | 11% |
| 2012 MAZDA6 | 2 | 2% |
| 2011 MAZDA6 | 3 | 2% |
| 2010 MAZDA6 | 4 | 2% |
| 2009 MAZDA6 | 11 | 3% |
| 2008 MAZDA6 | 2 | 2% |
| 2007 MAZDA6 | 9 | 6% |
| 2006 MAZDA6 | 10 | 6% |
| 2005 MAZDA6 | 4 | 3% |
Other reported problem areas on the 2018 Mazda MAZDA6
Counts are unique NHTSA complaints naming this component group. Complaints are unverified owner reports; mileage is computed only from complaints that included a usable odometer reading.