2018 Mazda CX-9 engine problems

Related recalls

No recalls on file.

What owners say

1. Filed Sep 17, 2026124,000 miCTEngine

   While driving at highway speed in heavy rain the oil light suddenly came on followed within 30 seconds by an urgent need to immediately stop the car due to overheating. There was no radiator fluid left due to the sudden and catastrophic structural failure caused by a known manufacturing defect. Mazda calls it csp-11. They did NOT do a recall even though a situation such as this is clearly life-threatening. They offer an extended warranty to fix the problem fully up to…

   NHTSA complaint #11764935 · source
2. Filed Sep 15, 2026PAEngine

   My 2018 Mazda Cx-9 equipped with the skyactiv-g 2.5T developed a serious cylinder-head/cooling-system failure. The vehicle began to lose coolant with no apparent external leak and subsequently displayed and engine -overheating warning. It continued to lose coolant after a flush. The Mazda dealership inspected the vehicle and diagnosed a warped cylinder head; I was also advised that the engine oil was milky, indicating coolant contamination. The affected component is the…

   NHTSA complaint #11764333 · source
3. Filed Aug 8, 2026INEngine

   I was driving home from work and may car started overheating out of nowhere. I was stuck in traffic and white smoke was exiting my exhaust. I pulled over and all of my coolant leaked out of my car. Took it the shop and they said I had a cracked head and need a whole new engine. I seen that there was a warranty sent out for a problem with an exhaust manifold issue leaking coolant and that is exactly what caused my problem. I contacted Mazda and they said there is nothing they…

   NHTSA complaint #11755628 · source
4. Filed Jul 15, 2026CAEngine

   The cylinder head on this 2018 Mazda CX-9 (Skyactiv-G 2.5T engine) cracked, allowing engine coolant to leak and intermix with engine oil, causing loss of coolant and catastrophic engine failure. The vehicle became undriveable in the first week of November 2025 at approximately 125,019 miles and has remained inoperable since; it was not in a crash and had to be towed. This matches a known, documented defect on Mazda's Skyactiv-G 2.5T engine: coolant leakage at the cylinder…

   NHTSA complaint #11750583 · source
5. Filed Jun 5, 2026NCEngine

   My wife was driving the vehicle when the emergency lights started going off. She had to pull over because the car wouldn't run and said it was overheated. All the maintenance has been done to the car. We took it to the dealership and they said it is a cracked head and it is a known issue. They even issued a extended warranty for it. It is TSB 01-002/23. There should be a recall on this not just a partial credit.

   NHTSA complaint #11742255 · source
6. Filed Mar 12, 2026CABrakesEngine

   My 2018 Mazda CX-9 experienced catastrophic engine damage after a radiator failure allowed coolant to enter the engine. The vehicle provided no dashboard warning, overheating alert, or coolant warning before the failure occurred. Modern vehicles are designed to alert drivers to overheating or cooling system failures. The lack of warning prevented me from addressing the issue and resulted in catastrophic engine damage. I believe this represents a potential safety defect in…

   NHTSA complaint #11723876 · source
7. Filed Feb 5, 2026IAEngine

   Here the facts, bought a car out of state (Illinois) from Iowa with 130,131 miles on Sept 12th 2025, Mazda CX9, the dealer did not disclose any problems with the car, after 3 months of ownership, the car overheats on highway whit family including a [XXX] infant, white smoke under the hood and exhaust pipe, towed home, radiator was replaced, few days after that a coolant leak, vehicle was sent to an authorized Mazda dealership for diagnose, the technician told us, according…

   NHTSA complaint #11716057 · source
8. Filed Jul 21, 2025ILEngine

   . In January 2024, I purchased a used 2018 Mazda CX-9. The vehicle ran well until [XXX], when I discovered an engine coolant leak. My mechanic diagnosed it as a known defect involving the cylinder head. My husband contacted Mazda Customer Service (CS), and they advised us to get an official diagnosis from a Mazda dealer. We brought the car to Orland Park Mazda, where a diagnostic confirmed the defect (report attached). We later received an email from Mazda CS saying that…

   NHTSA complaint #11674928 · source
9. Filed Apr 30, 2025PAEngine

   Our Mazda CX-9, having roughly 86,000 miles, had catastrophic engine failure while driving. This is caused by coolant leaking at the cylinder head and around the exhaust manifold. This in turn caused a crack in the engine block. Mazda refused to fix this as it wasn’t a “recall” and only a tsb sent out. 1000 of people have reported this issue, causing failure while driving but Mazda will not recall the engines nor fix them under an extended warranty. After a 4 month battle…

   NHTSA complaint #11657829 · source
10. Filed Nov 10, 2024CAEngine

    Fan is not working and car is overheating when driving in traffic or low speeds - from forums this seems to be a common issue with this make/model and year

    NHTSA complaint #11624426 · source
11. Filed Nov 8, 2024MDEngine

    coolant leaks at the cylinder head around the exhaust manifold. Caused crack in the head. The Mazda 2.5t engine has this common issue that Mazda knows about. Mazda has a bulletin out but has not issued a recall. Car over heated and I was left stranded. Took car to mechanic who says I need to replace my entire engine.

    NHTSA complaint #11624296 · source
12. Filed Oct 27, 2024FLEngine

    My vehicle was low on antifreeze. I brought it into the dealer and had them look at it. They told me there was an antifreeze leak inside the engine. I told them, I think there's a service bulletin on it. TSB-01-013-21 And there are updates to it. They told me that the antifreeze leak does not pertain to this service bulletin. I told them, how can that be? When it's an antifreeze leak with an engine that only has 66000 miles on it so far. I spoke to mazda customer service in…

    NHTSA complaint #11622142 · source

Source: U.S. National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation public data. Complaints are submitted by owners and are not verified by NHTSA or by us; a complaint does not prove a defect exists. View this vehicle on NHTSA.gov Methodology