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

Find something helpful? Spread the word.
Get notified about new defects, investigations, recalls & lawsuits for the 2018 Mazda CX-9:

Unsubscribe any time. We don't sell/share your email.

2018 Mazda CX-9 Owner Comments (Page 2 of 3)

« Read the previous 20 complaints

problem #39

Dec 052023

CX-9

  • miles

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

Cracked cylinder head resulting in no heat, leaking coolant and risk of overheating and fire. Crack on backside of cylinder head near exhaust manifold bolts. Weight of exhaust manifold is too much for the cylinder head and results in a Crack around the bolt. Cylinder head was casted too thin at the factory resulting in the head no being able to support the weight of the turbo and exhaust manifold. Mazda is not covering the defect under goodwill when customer is outside of warranty even though it effects every 2.5 turbo engine made between 2015 and 2020.

- Helmetta, NJ, USA

problem #38

Jan 192023

CX-9

  • 68,000 miles
The contact owns a 2018 Mazda CX-9. The contact stated that while the vehicle was parked, he observed condensation under the vehicle. The vehicle was towed to an independent mechanic where it was diagnosed that the engine needed to be replaced. The vehicle was repaired but the failure persisted. The contact stated that while the vehicle was parked, he observed condensation under the engine compartment and on the top of the engine. The vehicle was taken to an independent mechanic where it was diagnosed that there was a crack in the cylinder head and that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 68,000.

- Hollywood, FL, USA

problem #37

Nov 062023

CX-9

  • miles
My 2018 Mazda CX-9 developed a rapid overheating issue which was determined to be caused by a cracked cylinder head. This was a known issue by Mazda as noted in a technical service bulletin (Mazda TSB 01-013/21). I've been told by Mazda corporate and the Mazda dealership where the car is currently parked that this bulletin means nothing and will they will not cover the cost of repair. My extended warranty is also telling me that they will not cover the cost of repair because they don't cover damage caused by overheating. Even though The leak caused the overheating in the first place.

- Claymont, DE, USA

problem #36

Oct 012023

CX-9

  • miles

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

Coolant leak in the 3rd cylinder, causing the car to overheat and cracking cylinder head, making inoperable.

- Asheville , NC, USA

problem #35

Oct 162023

CX-9

  • miles
We noticed a coolant leak and took vehicle in for service. Told that engine has a Coolant Leak at Cylinder Head [XXX]. 5 year old vehicle, 56k miles. No other warnings. All maintenance has been previously performed as required. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Bend, OR, USA

problem #34

Oct 092023

CX-9

  • miles
As I was driving 26 mile trip to work I noticed a red light illuminated on dash indicating the temp was about 240-260. I pulled into the parking lot immediately turned car off. After work (8 hour shift) drove home temp stayed at 200-210. The next morning I took it to the mechanic I-??ve used for years. He did a visual detailed inspection finding that the water or antifreeze in the radiator was low. The antifreeze in the over flow tank was about an inch or so above the -??L-?? line. He said there may have been an air pocket in it, a leak, water pump or thermostat going out. Watch the fluid levels daily, if the lower again take it to the dealership where I purchased it (4 months ago with 106K miles on it). I do have a 3 year or 30,000 mile warranty through the dealership. 4 days later I was very observant watching the temperature gauge. It went up to 240 briefly, so I got home and had my ex-husband check it. Both the radiator and the overflow tank were bone dry. Topped off radiator with antifreeze and the overflow tank to the -??F-?? line. Car had cooled and right before topping fluid started. There is no noticeable sign of a leak (smell, white smoke from exhaust, visible puddles of anything on the motor or the ground where I-??ve parked. Today is Thursday 10/12 and I can-??t get an appointment with dealership until Tuesday. I-??ve been reading a lot online about this being a very repetitive issue. In some cases new engine replacement required. Mazda is well aware of not a few but NUMEROUS issues and complaints, a recall is needed for this situation. Right is right and fair is fair!!

- Ellisville , MS, USA

problem #33

Oct 092023

CX-9

  • miles

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

Went in to the mechanic to get a regular oil change and noticed a liquid slushing sound after starting the car up. Was informed that there is a major coolant leak somewhere in the car. Took it to Mazda dealership right away who confirmed that it is a cracked cylinder head. I got lucky that the car did not overheat on the road and happened to catch it in the nick of time. No check engine lights or low coolant lights came on at all.

- Houston, TX, USA

problem #32

Sep 292023

CX-9

  • miles
Coolant leak not from radiator but from the engine

- Pittsburg, CA, USA

problem #31

Sep 032023

CX-9

  • miles
Car started idling rough and losing power at 135000 miles. Then started to overheat. Mechanic noticed coolant was low and added some. Problem continued to get worse and now engine won-??t turn over. Mechanic said it was a cracked head leaking coolant into engine and it-??s a known problem with the CX-9.

- Houston, TX, USA

problem #30

Sep 182023

CX-9

  • miles
Just noticed coolant leak during oil change. Vehicle has 77,000 miles. Power train warranty is only to 60K. The vehicle is undriveable without major engine work or engine replacement.

- San Jose, CA, USA

problem #29

Aug 302023

CX-9

  • miles

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

The cylinder head cracked and leaked engine coolant at 72K miles. This is a known design flaw IAW TSB 01-007/22. Vehicle overheated.

- Mount Dora, FL, USA

problem #28

Aug 262023

CX-9

  • miles
Coolant leak from casting defect. Common issue.

- Litchfield , ME, USA

problem #27

Jun 012023

CX-9

  • miles
I noticed my 2018 mazda cx9 Sweet smell coming out of the engine.. When we were driving, a memo came up on my car screen and says please turn off vehicle as soon as possible, overheating. I was Scared That my car could have stopped in the middle of the freeway with my kids in it. My current was low. My engine was really hot and so we took it in to Mazda dealer. They diagnosed my car, and they said it had a cracked cylinder head by the exhaust manifold and because of that, it overheated my engine. This is a manufacturer problem. And it could have harmed my family. Mazda now doesn't wants to help me fix my this car, even when admitting they are fully aware of it. This happening on a freeway would have caused a major accident. There are Technical service bulletin on this case but people are Still in danger.

- Pearl City, HI, USA

problem #26

Aug 072023

CX-9

  • miles
The vehicle started leaking coolant, I had it towed to dealer to prevent further damage. They said it has a cracked head, which is a known issue with the 2016-2019 Mazda's, and is acknowledged by Mazda to be their fault. They have posted on a service bulletin that it was caused by added stress during manufacturing. Like many others, they want me to pay over 8k dollars for the repair. This is ridiculous as Mazda has stated that it is their fault.

- Commerce, MI, USA

problem #25

Aug 072023

CX-9

  • miles
Driving on a major highway, when the engine overheating temperature light appeared on the instrument cluster. Seconds later it appeared and felt as if the engine would seize and come to an abrupt halt in the middle of a major highway. Thankfully I was able to quickly find a place with room to pull over, avoiding a potential collision. The engine coolant abruptly leaked/exited from the vehicle. I believe there is a service bulletin (No.- 01-002/23), but still no signs of a Recall being issued in reference to this safety concern.

- Somerdale, NJ, USA

problem #24

Jul 142023

CX-9

  • miles
Started smelling coolant through AC and noticing that temp would momentarily spike to 240 before going back down to 200. My independent mechanic diagnosed it as a coolant leak in the cylinder head related to Mazda Tech Service Bulletin 01-002/23 (https://www.tsbsearch.com/Mazda/01-002-23). Took it to Mazda dealership, they confirmed a coolant leak and wish to replace the whole engine. Problem is that vehicle 1) has 105K miles and is not under warranty 2) Mazda engines are on back order and may not be available until November. I am going through an appeal process with Mazda right now to try to get some relief from a 9K repair bill. Disappointed that this known issue ( several threads in the Mazda forums ) is not getting the attention from Mazda that it deserves.

- Rockledge, FL, USA

problem #23

Jul 122023

CX-9

  • miles
A coolant leak appeared around 62,000 miles. Car started overheating and come to find that I had no more coolant left in the reservoir. I filled it back up and drove it to the mechanic, after almost a week in the shop and have been quoted over $2k for the fix. There is a TSB out on this issue. It is a known issue apparently from a casting defect in the heads / block.

- Henderson, NV, USA

problem #22

May 142023

CX-9

  • miles
A coolant leak appeared around 60,000 miles. I caught it in the right time as I had no more coolant left in the reservoir. I filled it back up and drove it to the Mazda dealership - I did not overheat at all so no warning lamps appeared. Upon taking it into the Mazda dealership, the engine was pulled and it was discovered that the cylinder head was cracked. This requires a new engine. There is a TSB out on this issue. It is a known issue apparently from a casting defect in the heads / block.

- Bethel Park, PA, USA

problem #21

May 252023

CX-9

  • miles
coolant leaks at the cylinder head around the exhaust manifold, safety was compromised by car overheating in the middle of extremely high level traffic, problem confirmed by Mazda dealership, only inspected by dealership, there was no warning indicators from the vehicle. I could smell antifreeze the day before it overheated.

- Summerville, SC, USA

problem #20

Apr 082023

CX-9

  • miles
A known faulty cylinder head in these cars is breaking. A simple search of the web shows numerous owners have had the same problem. Mazda dealers KNOW it is a problem. They have upgraded the part, but it comes at a cost of approximately $7800 to owners of said vehicles.

- Villa Rica, GA, USA

Read the next 19 complaints »

Not what you are looking for?