2016 Mazda CX-9 Engine
Owner-reported problems and safety issues filed with NHTSA. Review common failures, severity levels, and complaint trends over time.
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Coolant leak. Needs new motor to fix issue.
I just had my engine replaced due to a cracked cylinder head that allowed coolant to leak into cylinder #3 & #2.
The car has 75K miles on it and has always been maintained by either Mazda or independent garages. Engine overheating, took car to Mazda specialist and found the engine cylinder head is cracked. This is a known issue with this type of Mazda engine and Mazda has published a TSB which I attach. Car is unsafe to drive as coolant may leak completely at any stage and leave myself and family stranded. The cost of the fix exceeds $6,000!
First radiator blew (after noticing the temp gauge higher than normal and fan running a lot), and when replaced, the 2016 Mazda CX-9 continued to leak coolant. Took it to dealership to find out engine cylinder cracked and head gasket. A simple google search finds that so many Turbo Mazda’s between the years of 2016-20 experienced this design flaw as well. Mazda would not cover any of it since the car was out of warranty. It costed me over $7,000 to repair radiator and engine.
My 2016 Mazda CX-9 2.5l Touring has approx 67,500 miles. I noticed the "sweet" smell of coolant after driving. The temp gauge was not showing signs of overheating. I checked under the hood and coolant level in radiator and reserve tank were normal. I also did not see any coolant leak/patches under the car. Few days later the car temperature gauge shot past the 1/2 mark. i stopped the care let it cool and checked under hood. radiator was empty but reservoir tank was still full. there were signs of coolant drips underneath car on the plastic cover below the area of the water pump (passenger front wheel side). waiting to have car assessed/fixed by mechanic.
While driving, engine suddenly overheated due to coolant leak from cracked cylinder head. This was a known issue per the TSB 01-002/23. See attached. Vehicle only has 55k miles and has been maintained, only requiring oil change, topping off of fluids, and filter changes. Dealership has determined that it will require a completely new long block. Mazda USA is currently only willing to cover a small fraction of parts costs, requiring me to pay the remaining parts and all labor costs.
Head gasket blew in a 2016 Mazda CX9 while driving causing us to as safely as possible quickly get off the road from the middle lane of an interstate. This is from a known coolant leak in the cylinder head from service bulletin 01-013/21.
Car started running rough and losing power intermittently. After arriving home and parking the car, a puddle of coolant started at the rear of the engine. Online research indicates this is a known issue for the 2016 CX-9. Head gasket failure causes coolant leak from back side of engine at the head gasket. Coolant is still leaking 24 hours later without the car being run.
My engine head cracked whiling driving. sudden lost of complete power in houston texas at a 75mph speed. Was able to safely pull to the side. took it to the dealer where they confirmed it was a cracked engine head. Its a common issue with this model from 2016-2019 no warning light came on just lost 90% power. was able to restart and drive the 7 mins to the dealer.
Car overheated. check front engine and could not see any visible leaks. check all around the engine and found coolant leaking from the back of the engine. confirm by dealer that is leaking at the cylinder head.
I am being told by the dealership service center that there is a coolant leak from the engine. A previous coolant look due to a hose was repaired but this is a separate issue related to the TSB for coolant leak at the cylinder head Bulletin 01-007/22
Cracked Cylinder Head due to Coolant Leak - SB 01-013/21. This is a known issue with Mazda, yet it has happened with the vehicle being serviced regularly. This is happens directly after the warranty period and it is not being covered.
A strong coolant smell was noticed in the interior of the car and from the engine compartment. The diagnosis from the Mazda service facility was that there was coolant leaking from the head on the engine. Eventually this would have led to overheating of the vehicle which could have resulted in significant engine damage. The manufacturer has issued a technical service bulletin (TSB) for this problem. Cracking of the head that leads to coolant leaks is a known problem with this engine in several different models of Mazda including CX-5, CX-9, and Mazda 6. Our vehicle has remained in the shop since it was taken in on 11/8/2022.
Cracked cylinder head due to manufacturing defect, left stranded at car wash with no engine coolant due to issue, took several months without a vehicle before it was replaced by Mazda. The vehicle has been repaired. I was left unable to drive in hot weather and could not use air conditioning while waiting for assistance. Dealer had seen the issue before, reported by many on online Mazda forums. There were no warning lamps prior to the incident happening.
The cylinder head has cracked and it leaks antifreeze. This can cause the vehicle to overheat and destroy the engine. It is apparently a known issue as Mazda has issued 3 technical service bulletins addressing the problem. They have even redesigned a new part to replace the faulty one. In the TSB they even address that the crack may be caused by "stress generated during production" In other words, its a known problem yet they havent issued a recall on it. Im guessing they havent issued a recall because the quote for the repair was $5000. At $5000 to repair the faulty part it would be quite the expensive recall for the company.
My Engine is over heading because it has a crack and losing coolant externally. There are 74773 mills on my car. Every 3 weeks I have to put a gallon of coolant in the engine. if I don't put coolant, the engine can stop working on the freeway causing bodily injury to me and other drivers.
Purchased the car used with 67k miles on it. Within 2 weeks of purchase warning lights went off saying that the engine was overheating due to censor malfunction. After three visits to mechanics (2 to the dealership and 1 to a private mechanic) it was determined that coolant was leaking into the engine causing the engine block to crack. This of course means that the engine will have to be replaced in order for it to be useable. That repair has been quoted by the dealership as a $14,000 repair. For a car that has less than 70k miles.
I droved my 2016 cx-9 off highway and idled it at front of restaurant, suddenly the engine coolant overheat light came on, shut engine off and found leaking coolant on the ground near the rear of engine bay. Brought the car to Corpus Christi Mazda, found out leaks come from cylinder head crack, happens to cx-9 manufactured before June 20, 2020 according to Mazda TSB 01-013/21. I was quoted $3380 to replace the cylinder head out of pocket because the car is just out of powertrain warranty. I contacted Mazda headquarter for covering the cost out of goodwill since this is due to manufacture defects of cylinder head. Mazda refused to pay.
15 minutes after getting a wheel bearing replaced at the dealer, my engine coolant high temperature warning came on (never before seen). This occurred while I was on the interstate with no safe place to stop. When I was able to safely stop, I called the dealer. They said bring it back. I was unwilling to drive that far so chose the closest Mazda dealer. They informed me I have a cracked cylinder and the coolant is leaking into exhaust system. I was told the only option due to the mileage on the car (134,000) is to replace the engine for $8,000. This appears to be a known issue so I am shocked that it wasn't being checked for prior to the problem.
Cylinder head cracked, leaking coolant and causing engine overheated , potential fire hazard . Coolant also leaked and mixed in with oil cycling through engine , causing permanent damage to the engine , resulting engine to be fully replaced
2016 cx9, after reviewing online. Known issue with coolent and engine cylinder. Water coolent leak to engine head. Dealer asking 75k to replace engine. Mazda refused to acknowledge the known issue.
Dealer diagnosed manufacturing defect that caused crack in head. {Which could lead to engine failure, and subsequent accident due to engine failure during operation.} Engine lost coolant. No overheating noted. No warning/error codes noted.
The contact owns a 2016 Mazda CX-9. The contact stated that while driving at an undisclosed speed, the air conditioning became warm and the fan was abnormally loud. Additionally, the engine temperature gauge was high. The contact pulled over and refilled the coolant reservoir. The vehicle was taken to an independent mechanic who initially diagnosed that the water pump was faulty and needed to be replaced. However, when the contact took the vehicle back to the independent mechanic for the water pump replacement, the mechanic diagnosed that the cylinder head was warped and referred her to the dealer. The vehicle was not repaired. The dealer was made aware of the failure and informed the contact that there was no recall associated with the VIN. The manufacturer was made aware of the failure and informed the contact that there was no recall associated with the VIN and referred the contact to file a complaint with the NHTSA. The failure mileage was approximately 120,000.
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Quick Summary
The 2016 Mazda CX-9 has 48 Engine complaints on file. Review the timeline above for detailed owner experiences.