2016 Mazda CX-9 Engine Problems

I own a 2016 Mazda CX9 Touring FWD (180k miles). Today my car was diagnosed with cracked cylinder head, resulting in coolant and oil leak from the head gasket. While there is a class action settlement about it where Mazda accepted the manufacturing defect, they do not cover the engine repair/cylinder head replacement because my car's mile is over 120k. If it is a manufacturing defect, why year/mile make a difference on the responsibility of the manufacturer? Mazda obviously sold defect vehicles to their customers, and driving these vehicles under this condition is very dangerous! Now, they are expecting me to pay more than $10,000 for a vehicle priced around $6,000!

Cylinder head crack. Combustion gasses leaking into coolant causing overheat. Combustion gasses bleeding into oil causing excessive crankcase pressure.

In June of 2022 I started having a strong antifreeze/engine coolant smell inside the cab of my vehicle and also outside the vehicle. I had the car checked for a radiator leak, but there wasn’t one. I took my car into my local Mazda where they found that the engine coolant was leaking into the heads of the engine. Mazda kept my car for 5 months and repaired the problem, it cost me $4000 and they had added a 12 month 12,000 mile warranty for the parts. My car is a 2016 Mazda cx-9 at the time of the repair it had 70,430 miles on it. Now a few years later I am having the same issue with the coolant smell inside the cab and outside my vehicle, it goes into the shop for diagnosis on Monday November 10,2025. The car now has 118,000 miles on it. I had purchased an extended warranty for the car at the time of purchase but it had timed out a month before I took my car in for the first repair….please Mazda stand behind your vehicles I am a senior woman with very little income and I will not be able to pay out of pocket for this repair and I CANNOT afford a new car… I would like to get reimbursed for my out of pocket on the first repair and get my car repaired this time as well under a warranty.

Engine failure with crack in the engine after a loss of coolant fluid.

Sudden and dramatic loss of engine coolant. Received a warning that engine was overheating, and to shut off engine. Quickly obeyed the prompt and found that most of the engine coolant had been lost due to a catastrophic failure of either the head gasket or head itself.

The contact owns a 2016 Mazda CX-9. The contact stated that while driving approximately 45-50 MPH, the vehicle suddenly lost motive power with white smoke coming from the front of the vehicle. The contact was able to get to the side of the road to inspect the vehicle and became aware that there was coolant splattered all over the engine compartment. The failure had occurred twice. The “WRENCH” symbol was displayed with the “Service Vehicle” message displayed. The vehicle was taken to the dealer, who diagnosed that the coolant pump and water pump were leaking, and the radiator needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The manufacturer opened for the failure. The failure mileage was approximately 148,000.

Head gasket leaking and caused major engine issue at 89,000 miles. Mazda has known of this issue, but refuses to recall it.

While my wife was driving her 2016 Mazda Cx-9 Grand Touring on the freeway, many of the dashboard indicator lights came on warning her the engine was over heating and to pull over immediately. While she was attempting to move over to the shoulder, smoke appeared from underneath the engine hood which made it difficult to safely move over to the shoulder. She believed the car was on fire so immediately exited the vehicle along with her sister whom was pregnant. I arrived within minutes and noticed the engine compartment was smoking and coolant/engine oil leaking underneath the car. The car was towed to my local Mazda dealership where I was advised days later the engine needed to be replaced due to blown head gaskets. They advised the vehicle over heated causing oil and coolant leaking from cylinder head that is warped. This repair would cost $11, 179.29. Mazda service advisor also mentioned the radiator and lower/upper radiator hoses needed to be replaced. This repair would cost $2691.28. This incident could've resulted in serious injuries or death from a known issue with these engines by Mazda. It's only a matter of time before this failed engine turns into a fatality. Do the right thing Mazda and fix these engines. Your reputation is on the line.

Cylinder head coolant leak. No warning lights.

Coolant sprayed on top of engine

Our 2016 Mazda CX 9 began leaking coolant and we took it to a shop who diagnosed it as coming from the cylinder head, requiring a very expensive repair or new engine. Luckily our engine did not sieze up while driving, but it easily could have with our baby and toddler in the car. Upon searching the internet I found countless reports from other CX 9 owners who experienced the very same issue at similar mileage ~50k-70k. There is a technical service bulletin for this issue, but they have not issued a recall. This very expensive repair is going to set us back significantly and is a financial burden we were not expecting from our well cared for vehicle. It seems Mazda knows about the issue and is unwilling to address it.

The contact owns a 2016 Mazda CX-9. The contact stated while driving at an undisclosed speed, the check engine warning light illuminated, and the vehicle started shuddering and overheating. The vehicle was taken to an independent mechanic who diagnosed the vehicle and determined that the failure was related to a cracked head gasket. The vehicle was not repaired. The contact related the failure with the Technical Service Bulletin: 01-03/21; however, the vehicle was not included. The manufacturer was not notified of the failure. The failure mileage was approximately 92,000.

Cracked cylinder head causing coolant to leak.

Vehicle had a horrible coolant leak at the rear of the engine to find out the engine has a weak cylinder head and is known to break and leak coolant. The vehicle will need a new cylinder head or engine replacement.

My car has a cracking cylinder head and is leaking coolant.

A month ago, I experienced a coolant leak at the back of the engine compartment. Upon researching I found that the head was prone to crack at the turbo and produce the leak. I took to my dealer, and they confirmed that it was in fact a cracked head causing the coolant leak. They also confirmed it was a known Mazda problem on the 2016 and newer 2.5 liter turbo engines. The dealer fixed four in the last month and one on a car their salesman purchased that the head failed at only 2000 miles. I was quoted a cost of $5965 for cylinder head replacement. It seems extremely excessive for a new cylinder head and a more appropriate price for a completely new motor. If this is a known defect on this motor no matter the miles, it seems Mazda should correct this problem in or out of warranty.

2016 Mazda CX-9 is leaking coolant from exhaust side of engine cylinder head. This issue has been confirmed by a Mazda dealership in North Charleston, South Carolina. The issue first appeared shortly after replacing the water pump (performed by the same dealership). The issue is known and documents on Mazda TSB 01-002/23 - COOLANT LEAKS AT CYLINDER HEAD. The safety of my family was put at risk as there was no indication of a cracked head until there was coolant leaking on the driveway. Should the car have overheated without the indication of a coolant leak, the car would have been placed in to limp mode. Prior to the leak, there were no warning lamps or messages indicating the issue. Further, the Mazda dealership did not detect the issue at the time of replacing the water pump.

The contact owns a 2016 Mazda CX-9. The contact stated that while driving at an undisclosed speed, the vehicle stalled. Several unknown warning lights illuminated. The contact stated after the vehicle cooled off, the was able to be restarted. The contact checked under the vehicle and stated that there was coolant leaking on the ground. The vehicle was taken to an independent mechanic, where it was diagnosed with a coolant leak behind the engine. The vehicle was not repaired. The contact related the failure to Technical Service Bulletin: 01-002/23. The dealer referred the contact to the manufacturer for assistance. The contact was unable to reach the manufacturer for assistance. The failure mileage was unavailable.

We noticed anti-freeze leaking from our car a couple of days ago and immediately brought the car to our local mechanic. The mechanic determined that one of the cylinder heads in the engine was cracked and was leaking anti-freeze. He said the car was unsafe to drive. He also told us that a TSB had been issued by Mazda for this problem ( Bulletin No 01-002/23, issued 02/10/23). This bulletin states "Residual stress generated during production in the cylinder head material may be greater than expected. The external force from the exhaust system when driving over bumps may cause unexpected force to certain areas of the cylinder head". Had we not noticed the leak, the engine could have overheated, causing the engine to seize at any time, any place. which could have led to a dangerous accident. An accident that could have occurred on a major highway and could have involved other vehicles as well. Our car has just under 80,000 miles, has been well maintained and garage kept. I do not understand why a manufacturing defect such as this - which could lead to engine failure is not a mandatory recall by the manufacturer. We should have been warned that this could happen and mazda should be responsible for the cost of the repair. It is an engineering design flaw of the vehicle!

Engine head cracked. Known problem with a tsb issued