2018 Mazda CX-9 engine problems
78 of the 128 complaints owners filed with NHTSA about the 2018 Mazda CX-9 name the engine (NHTSA’s “Engine” heading — the engine and its cooling system). Filed under the same heading: 106 manufacturer bulletins. Every figure below is a document in a federal file, linked; none is a failure rate, and none is a verdict on any one car.
What owners filed about the engine
Source: NHTSA complaint database0 of the 78 reports a crash · 0 a fire · 0 injuries. Self-reported, unverified.
Filed per year: 2019: 1 · 2021: 2 · 2022: 9 · 2023: 30 · 2024: 25 · 2025: 4 · 2026: 7
Too few of these complaints carry an odometer reading to say when the problem shows up.
128 complaints in all about the 2018 Mazda CX-9, 7 filed in 2026. The whole picture, every system →
Counts are owner reports to NHTSA, not verified defects, and scale with how many of these were sold; nothing here is a rate. NHTSA groups complaints coarsely, so “Engine” means the same area of the vehicle, not one fault.
Across model years: Mazda CX-9 engine problems, every year on file →
In owners’ own words
Source: NHTSA complaint databaseFiled with NHTSA by the people who own these cars, about the engine. Quoted as written, with anything identifying removed; unverified reports — what was said, not a finding that it was true.
Driving the car home from work, the engine temperature gauge started to go up high. I added coolant that same night. Went to the dealership for a check up. I was told the coolant was coming out from the back of the engine and will need to partial repair the engine.
After owning this used vehicle for about 11 months, the engine temperature gauge indicated the car was running hot - about 240 degrees. After inspecting the vehicle at home, we added coolant to the system. This helped maintain engine temperature temporarily, but we noted over the next several weeks that the coolant was dropping rapidly.
I have a 2018 Mazda CX-9 with about 66,000 miles. I noticed a coolant leak when my SUV sat in my driveway. It was there each night after driving the SUV. I took the vehicle to a Mazda dealer who stated that the coolant leak is from a cracked cylinder head. A cylinder head should not crack in 4 years and only 66,000 miles.
I noticed a smell of antifreeze. After taking it back to dealership, I find out it has a cracked head. It has never ran hot
The cylinder head failed causing a massive leak of engine coolant. This occurred initially at highway speeds which caused potential danger to myself and others around me as the car was required to pull over immediately. The problem was confirmed by the dealer and is known to the manufacturer as indicated by TSBs.
What is on file about the engine
Source: NHTSA recalls, investigations and manufacturer communications106 manufacturer bulletins filed under this heading
- SA-041-26 Service bulletinJun 19, 2026
- This SA supersedes the previously issued SA(s) listed below. The changes are noted in Red. SA-061/25 12/17/25 DESCRIPTION If you encounter any type of electrical concern (e.g, dead battery, engine no start, DTC(s) stored...), interview the customer before proceeding with normal MGSS diagnosis by asking if any aftermarket devices have been installed. Aftermarket devices may be the cause of the elec
- SA-026-26 Service bulletinApr 16, 2026
- 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 mechanical failure, clean the intake manifold internally before installing a replacement engine assembly. If the intake manifold is not cleaned properly, the replacement engine may f
- SA-014-26 Service bulletinMar 11, 2026
- This 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 faulty, due to signs of a very small coolant leak from the bleed hole. This Service Alert is to inform you about the water pump sealing mechanism and the criteria if replacement is ne
The 3 newest are listed; every one is on the model year’s page. Quote the document number at a service desk — it is a diagnosis the maker has already written down.
Trouble codes named on this system
P0780 P0842 P0847 P0872 P0877 P1738 P2507 P2610
Codes a bulletin or an owner’s complaint about the 2018 Mazda CX-9 names on this model year; a code with a record of its own links it.
Common questions
Source: NHTSA complaint database, recalls and manufacturer communicationsAre engine problems common on the 2018 Mazda CX-9?
They are documented: NHTSA holds 78 owner complaints naming the engine on this model year (61% of everything owners filed about it), and 106 manufacturer bulletins are filed under the same heading. Whether it is a problem on one particular car is a diagnosis, not a count, and a count says nothing about how many were sold.
Is there a recall for the engine on the 2018 Mazda CX-9?
No recall campaign is filed under this heading for this model year (there are 2 filed under other headings). A bulletin is not a recall: it carries no federal duty to repair for free.
When do engine problems show up on the 2018 Mazda CX-9?
Too few of the complaints carry an odometer reading to say. The model year's page shows the mileage curve across every system where it can.
What does NHTSA's "Engine" heading cover?
The engine and its cooling system. Owners choose the heading when they file, so it says which area of the vehicle the complaint is about, not which part failed.