9.3

really awful
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
1,514 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2018 Mazda CX-9 engine problems

engine problem

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2018 Mazda CX-9 Owner Comments (Page 1 of 3)

problem #59

Sep 212024

CX-9

  • miles

A D V E R T I S E M E N T S

Over heating /coolant leak

- Hedgesville, WV, USA

problem #58

Sep 202024

CX-9

  • miles
coolant leaks at cylinder head, Mazda of America knows issues but not willing to recall, they hava a bulletin number 01-002/23. pls help

- Smyrna, TN, USA

problem #57

Aug 262024

CX-9

  • miles
While driving on an interstate service drive in Michigan, my 2018 Mazda CX9 GT suddenly lost power and began flashing overheating warnings. I tried to move my vehicle to a safe spot while the warning and sudden loss of power was happening, which took a moment due to traffic flow and my family being in the car. I moved the car off the road, and let it cool. I slowly drove the car to a parts store to get coolant. Once the cooling system was filled, I brought the car home and began researching the problem. According to internet threads like Reddit this is a wide spread problem happening among Mazda vehicles with several law firms researching class action lawsuits. My car is stuck at the dealership until I can find $12,000 to fix it, and sadly there are hundreds more just like me according to sites like [XXX] and [XXX] [XXX] [XXX] [XXX] [XXX] [XXX] And includes a Mazda Service Bulletin which indicates that there are design faults in the original cylinder head that causes the issue and that repair techs should replace failed parts with the updated and redesigned cylinder head. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Ypsilanti, MI, USA

problem #56

Aug 072024

CX-9

  • miles

A D V E R T I S E M E N T S

Approximately three weeks ago, a message on my dashboard said to pull over immediately. Your car is overheating. I pulled over to a nearby auto shop, which indicated that I was just low on coolant. They topped off the coolant, and everything appeared fine. Two weeks later, I got the same message on the dashboard, saying my car was overheating to pull over immediately. I pulled into a nearby auto parts store and purchased coolant for the vehicle. When I checked the reservoir, it was bone dry. I added coolant and drove the car home. The following day, I checked the reservoir to see if there was still coolant, but it was all gone. I scheduled an appointment with the Mazda dealer to have the car inspected. I also checked the Mazda Forum website to see if other vehicles of my make and model had similar issues since I had never experienced this before. I found that the overheating in vehicles of my make and model was a "known issue" with Mazda. When I took it to the dealer the next day, the service agent informed me that the "known issue" was only with the Turbo model. I explained that my vehicle is a turbo model. He said that Mazda did not have to cover any costs because no recall was issued, even though it is a known issue. Mazda is now refusing to cover the repair and has indicated that the repair and replacement of the engine will cost approximately $9800. If I had been alerted earlier, I would have been able to have the car repaired.

- Denver, CO, USA

problem #55

Aug 222024

CX-9

  • miles
Vehicle had bucking coming to a stop. Noticed coolant was l9w, and temp guage was fluctuating at a stop slightly. Brought it to Lester Glenn mazda in toms river NJ, service writer informed us it is the cylinder head, and that the repair is approx $11,000. Vehicle only has 85000 miles on it, and was told by dealer that there is nothing they will do. This is a known issue, with a TSB issued in 2021 due to a defect in design where the turbo charger is mounted to the cylinder head. At this point, we are requesting the manufacturer take at least part of the responsibility of the poor design they sold to the open market, that is clearly a safety hazard to my wife and 4 kids, 1 of which is an infant.

- Browns Mills, NJ, USA

problem #54

Jul 292024

CX-9

  • miles
Engine is leaking coolant apparently due to a cracked engine block caused by a manufacturing defect in the casting. Mazda has a Technical Service Bulletin, subject:Leaks at cylinder head and the number is 01-013/21. But they refuse to help cover their mistakes and now we owners are stuck with replacing an entire engine out of pocket. Shame on Mazda

- Carrollton, GA, USA

problem #53

Jun 302024

CX-9

  • miles

A D V E R T I S E M E N T S

Mine Mazda 2018 CX9 had coolant leakage at 55K miles. Issue is with faulty cylinder head acknowledged by Mazda in below mentioned TSB. I open up a case with Mazda (File Number XXX). Dealer quoted 7500$ expense and Mazda is providing assistance of 3101$. I have always serviced at Mazda authorized dealership and this issue was never reported. TSB [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Cumming, GA, USA

problem #52

Jun 102024

CX-9

  • miles
My car started leaking coolant from cylinder, it is known issue for these models, unfortunately Mazda cooperation doesn-??t cover the expenses, there is Service Bulletin about it, so basically so many car got affected or will affect from this problem. It is manufacturer fault, not about customer usage or mistake.

- Belgrade, MT, USA

problem #51

Jun 222024

CX-9

  • miles
"High coolant temperature warning. Stop car at a safe place immediately " came up. Stopped car at a mechanic and diagnosed as coolant leak onto the engine.

- Livingston, NJ, USA

problem #50

May 012024

CX-9

  • miles
Due to the flawed engine design which is well documented for these engines, ours started leaking coolant and it was eventually discovered that the head had cracked, and we were forced to have the head replaced. This repair cost us approximately $7600. Our hope is that Mazda will eventually issue a recall.

- Topeka, KS, USA

problem #49

Apr 262024

CX-9

  • miles

A D V E R T I S E M E N T S

2018 CX9 with 74k miles. Took it back to the dealer where I bought it from and have an extended warranty. They are telling me the extended warranty denied the coverage for Coolant leak, engine replacement

- Laveen, AZ, USA

problem #48

Apr 272024

CX-9

  • miles
Cylinder head cracked at 100k. There is tsb knowing that this is a problem. It even stats that it happens during Manufacturing there was a defect. Coolant is leaking out the back side of the motor. Causing a over heating conditions stranding my family on the side of the highway.

- Jewett City, CT, USA

problem #47

Apr 152024

CX-9

  • miles
The 2018 Mazda CX-9 has been experiencing significant engine coolant leaks, which are suspected to stem from a manufacturing defect. The coolant leaks appear to be primarily caused by a casting defect in the engine block or cylinder head, exacerbated by the pressure and heat from the attached turbocharger. These defects lead to coolant escaping from areas that are typically obscured behind the exhaust manifold and turbocharger, making early detection difficult without detailed inspection.

- Bristol, RI, USA

problem #46

Apr 022024

CX-9

  • miles
Car started leaking coolant, and running rough / stalling. Eventually overheated due to lack of coolant. Mazda dealer reports Cylinder Head crack as the root cause of the issue. Car has 106K miles - and seems to have the same problem as referenced in NHTSA 10232269 [XXX] ) Mazda has decided to decline to offer any financial assistance in the repair. Replacement cost for just the cylinder head (not a complete engine) was quoted by a Mazda dealership to be $6800 - $7200. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Louisville, KY, USA

problem #45

Aug 302023

CX-9

  • miles
Engine coolant leaks at cylinder heads I started noticing the problem at around 50000 miles its a small coolant leak but car is almost 6 years old and now 54000 miles

- Belvidere, IL, USA

problem #44

Jan 202024

CX-9

  • miles
I recently bought a Mazda CX-9 and noticed that my vehicle was slightly overheating. The coolant level was very low. I took it back to the dealership I bought it from and they confirmed that there was a crack in the cylinder head and are working on the repair. After further research, I am seeing this is common with these models. Mazda is aware but not taking responsibility.

- Austin, TX, USA

problem #43

Jan 192024

CX-9

  • miles
Cracked Cylinder Head Verified by Mazda Dealer. Noted it seems to be a very common problem with Mazda cx9 2018 models and has Multiple TSB on issue so I kept very close eye on car and took it in as soon as I smelled burning smell suggesting a leak, before the car had the chance to overheat and put myself and kids in danger. My car is under 40k miles for a 2018 with consistent maintenance - this is known problem since 2021 and needs to result in a recall.

- Clarks Summit, NY, USA

problem #42

Jan 122024

CX-9

  • miles
Mazda has a known technical service bulletin [XXX] which has numerous engine cylinder heads which leaks coolant causing the engine to overheat without warning. On new cars. Mazda knows it-??s an issue and has not pushed this information down to its consumers. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Alexandria, VA, USA

problem #41

Dec 212023

CX-9

  • miles
Engine coolant leaking due to cracked cylinder head, found by Mazda dealership service inspection and diagnostics. Powertrain warranty only covers this until 80,000 miles, our vehicle is 116,000.

- Geneva, IL, USA

problem #40

Dec 152023

CX-9

  • miles
At 102,000 miles I have a cracked cylinder head

- Chilton, WI, USA

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