Engine And Engine Cooling Problems of Mazda CX9 - part 1

Engine revs or surges while in park, possibly faulty throttle box.

See all problems of the 2016 Mazda CX9 🔎.

It’s now in the shop being torn down for further inspection but it looks to be a cracked cylinder head leak .

See all problems of the 2019 Mazda CX9 🔎.

The vehicle was parked stationary in the driveway with the engine running for 3-5 minutes with the a/c on. The vehicle then accelerated forward into my garage causing damage. Once I entered the vehicle, both the dash and shifter displayed park. Current tcu system internal failures have been reported from the pulling of data from Mazda.

See all problems of the 2021 Mazda CX9 🔎.

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 can do. I will have to hire a lawyer and file a class action lawsuit. I never recieved anything from Mazda regarding the issue. They should be paying for my car. I had zero issues until the day it faulted out. I am outraged that I had a great car then something that Mazda knew about cause me an issue.

See all problems of the 2018 Mazda CX9 🔎.

This complaint refers to Mazda and it's dealer refusal to properly execute the warranty work under the sspd5 valve stem seal class action campaign and does not follow the court's approval of the final settlement agreement. I assert that Mazda and it's dealer are not following the sspd5 repair procedures. 1. I have documentation and complaints going back to Dec-2023 with this particular dealer that I have experienced low level oil consumption within the 7,500 mile oil change interval. The dealer did not detect oil leaks in any of the engine systems. 2. I presented the vehicle to the dealer with the engine oil level warning light illuminated. The diagnostic trouble code (dtc) p250ff:00 should be stored in the vehicle memory. 3. The vehicle had 50,501 miles and was within the original 60 month limited powertrain warranty. 4. The dealer refused to conduct the valve stem seal repairs until an oil consumption test was run. The dealer claims that because I had another service center (note that I use full synthettic oil that meets Mazda oil specifications) conduct the most recent oil change at 43,738 miles (note within the 7,500 oil change interval and the 1 year time window) that the dealer would require an oil consumption test. I assert that this is not required per the class settlement agreement and the sspd5 repair procedures that Mazda sends to all of its dealers. 5. I researched the available documentation that it's available through the NHTSA. Gov. The language in these documents is very clear. 6. Sspd5 valve stem class action campaign, repair procedure 6-12-2024: a. "the dtc250 is not required to be present for valve stem replacement. " b. "customer complaint of oil consumption. . . Or low oil light or dtc250 follow the flow chart. " c. Flow chart says "replace the exhaust valve stem seals by following TSB 01-003/24" if no previous warranty work done. 7. Sspd5 updates on 8-6-25 and 4-28-a. Refer to page 4, dtc250 is not required to be presented (it is noted in red).

Check engine light comes on and error p0303 comes on. Had an independent mechanic do the following and after each one, error p0303 still came on 1. Swap the ignition coils from 2 to 3 2. Swap spark plugs from 2 to 3 3. Swapped injectors 4. Compression test 5. Leak down test 6. Changed the spark plug, coil and injectors 7. Looked for vacuum leaks. Mechanic believes that it is related to the cracked cylinder head in the recall, mc-10232269-0001. Pdf. My vehicle is just outside of the recall range and has 87k miles on it. Other research online shows other people with the same vehicle and similar milealge are also having this problem.

1) what component or system failed or malfunctioned: on 6/12/2026 while drive on the highway with our daughter in the car and we experienced a high speed stall. The engine failed and we lost power. We barely got the car of the highway and coasted into a parking lot. 2) life threating for father, mother and daughter and other drivers on the highway. 3) the Mazda dealer stated they were unable to reproduced problem. The diagnostic report showed few random misfired on two cylinders 2 & 3. Autozone detected codes p0300 with secondary dtcs u0442-00 4) there car was only inspected by the dealer. The vehicle has not been inspected by Mazda the manufacturer. We requested Mazda to escalate this to the district service manger and to open hotline call with Mazda corporate but both of these were denied. All our service has been performed at Mazda dealer, including oil changes. We have always received a video of them working on our car with a detailed summary of what done. We did not receive the video or diagnostic report for this issue. 5) there were no warning lamps, no messages or other symptoms of the problem prior to the failure.

This is covered under csp11. The problem is my car is a 2017 and they only allow a warranty up to 120,000 miles mine is at 158000 and they will not fix the problem now even thought we just started having problems.

See all problems of the 2017 Mazda CX9 🔎.

The engine cylinder head developed an internal coolant leak, allowing coolant to enter the combustion chamber. This caused engine overheating and smoke coming from the tailpipe while driving. A dealer performed a coolant pressure test confirming coolant leaking into the combustion chamber, and wet/dry compression testing on all 4 cylinders showed low and inconsistent readings consistent with cylinder head coolant intrusion (cylinder 1: 105/125 psi, cylinder 2: 115/125 psi, cylinder 3: 110/175 psi, cylinder 4: 160/190 psi). Overheating creates a risk of sudden loss of power and potential engine failure while driving, including on the highway. The problem has been confirmed and diagnosed by an authorized dealer service center, and the manufacturer's technical hotline department reviewed the diagnostic findings directly. Warning symptoms (overheating codes and visible tailpipe smoke) first appeared at the time the vehicle was brought in for diagnosis. The manufacturer has an active technical service bulletin addressing cylinder head coolant leaks on this engine and model, along with a related warranty extension program, but has denied coverage for this repair on the basis that the leak is internal rather than external.

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.

My 2019 Mazda cx-9 (VIN [xxx]) suffered catastrophic cylinder head failure on the skyactiv-g 2. 5t engine at approximately 124,000 miles. The failure is consistent with Mazda TSB 01-013/21 (and successors 01-007/22, 01-010/24), in which Mazda acknowledged that cylinder heads on this engine can crack at the stud bolt hole and exhaust manifold flange due to manifold deformation and residual production stress. The first warning came in mid-may 2026, when the engine temperature warning illuminated during normal driving. An independent mechanic replaced the thermostat. The warning returned within a week, and the thermostat was replaced a second time with a higher-quality part. Four to five days later, the warning returned alongside more severe symptoms: the vehicle began jerking while in motion, a strong coolant-burning smell developed, and smoke was visible from the exhaust pipe upon shutdown. The vehicle became undriveable, had to be left at the failure location, and was towed. Safety risk: the jerking compromised vehicle control in traffic. Upon shutdown, smoke and burning coolant odor created fire and fume-exposure risks. Had this failure occurred at highway speeds or in heavy traffic, the sudden loss of engine power and erratic behavior could have caused a serious collision. Family members were in the vehicle during several escalating events. Confirmation: the vehicle was towed to an authorized Mazda dealership, where Mazda-certified technicians confirmed in writing that it is exhibiting the exact defect described in TSB 01-013/21 and that complete engine replacement is required. The diagnosis is formally documented and has been communicated to Mazda's warranty team. Mazda customer experience has been engaged since mid-may 2026 and acknowledged the issue. The vehicle is currently at the dealership and available for inspection upon request. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

The cylinder head (which involves the engine cooling system) has a known manufacturer defect that affects all year/models of the Mazda cx-9 with turbo. The manufacturing defect poses a risk to motor vehicle safety in a group of vehicles or equipment of the same design and/or manufacturer. Specifically, the overheating and failure of the engine can occur at any time, without warning. This puts my family at risk of being stranded on a roadway, particularly because my car is often driven in rural areas. The manufacturing defect is significant and is acknowledged by Mazda: Mazda has offered owners a voluntary, limited, warranty extension (csp11) of 10 years or 120,000 miles. The voluntary warranty extension is not sufficient because it is limited in duration while the safety risk can happen at any time after the warranty extension expires. The warranty extension essentially only applies to about half of the expected lifetime of the car. Nhtsa should determine that a recall and repair should be issued by Mazda that does not expire. The engine is defective, poses a safety hazard, and Mazda has fixed the engine for subsequent models (starting in 2021), so a repair is available.

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 the vehicle’s cooling system monitoring and warning system.

Engine throwing a code after dying at intersection. Found that it isa known issue for this vehicle and repair costs are astronomical. Diagnostic summary: 2013 Mazda cx-9 (3. 7l v6)issue: faulty crankshaft/camshaft correlation (code p0016)current mileage: ~160,000 miles reported symptoms: extended cranking (long start), rattle upon startup, and rattle under light acceleration. The 2013 Mazda cx-9 is known for a serious issue where the internal water pump fails, allowing coolant to leak into the oil, which causes timing chain failure and potential engine destruction. I wish I knew this years ago. . .

See all problems of the 2013 Mazda CX9 🔎.

The contact owns a 2013 Mazda cx-9. The contact stated that while driving at an undisclosed speed, the vehicle shuddered abnormally. The check engine warning light was illuminated. The vehicle was taken to a dealer, where it was diagnosed, and determined that the lower control arm needed to be replaced. The vehicle was repaired; however, the contact had not received documentation of the repair. The manufacturer was notified of the failure and informed the contact that the vehicle was repaired under an undisclosed recall. The failure mileage was approximately 188,000.

- coolant leak at cylinder head and turbo at only 63,000 miles. - safety issue because no warning lamps or messages appeared and potential for car to overheat without coolant circulating in the system. Car could breakdown at worst time and location. Leaking coolant onto exhaust created potential for fire. - problem has not been confirmed by dealer yet. Appointment is upcoming. - symptoms of the problem were leaking coolant on ground, low coolant level, heater not working properly. - first appeared 1/29/2026.

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 to Mazda procedures, a cod p111a, the vehicle's engine reached unsafe level of temperature and the whole engine needs to be replaced because a cracked head cylinder. This problem is well known by Mazda because they addressed on a tsb01-002/23 and csp11 extended warranty, there is a flaw in the design of the engine near the cylinders manifold area, that cracks the engine and requires a full replacement of the engine. Its just a flaw in the design of the engine. This issue can appear at any point threatening the life of the occupants of the vehicle information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

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!.

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 head near the exhaust manifold, leading to overheating and engine failure. Mazda issued technical service bulletin(s) addressing cylinder-head cracking and coolant intrusion, revised the cylinder-head casting (a superseding part number), and extended warranty coverage (program csp11) for this specific concern. This vehicle fell just past the mileage cap of that extension. Safety risk: a cracked cylinder head causing coolant loss and engine overheating can produce sudden loss of engine power and overheating if it occurs while driving. No crash, fire, or injury resulted in this case. A formal dealer diagnosis is pending; the failed engine/cylinder head is being preserved and is available for inspection on request.

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

1. What component or system failed or malfunctioned, and is it available for inspection upon request? answer: engine failure due to overheating. 2. Safety & indicators: answer: during evening rush hour traffic on a 3 lane highway my car went into a form of engine power saving mode while I had children in the vehicle; this was almost catastrophic form my family and the other vehicles around me. There was no warning. There were no previous issues with my vehicle, this was unexpected. 3. Technician review: this is a known issue with no warning: the technician inspected your vehicle and found a concerning issue with the engine overheating. They scanned the vehicle and found a trouble code p111a, indicating the engine coolant reached a temperature of 251. 6 degrees fahrenheit, forcing the engine into limp mode. Based on their experience, the technician believes the engine likely reached much higher temperatures, potentially causing internal damage to the engine block. After a thorough inspection, they found no external coolant leaks, but upon using a digital borescope, they discovered evidence of coolant entering and being burned off in cylinder 3. Given the severity of the issue, the technician recommends replacing the entire engine to ensure the long-term reliability and extended life of your vehicle. Services completed: - scanned vehicle and found trouble code p111a - inspected engine and found no external coolant leaks - used digital borescope to inspect cylinders and found coolant entering cylinder 3 recommendations: - replace the entire engine.

I took our vehicle into Mazda due to a coolant leak that could not be located. It had my wife stranded due to the vehicle overheating. Everything lined up with csp11. The dealership is now stating that the vehicle has a blown gasket and needs an engine replacement. This is the issue covered by csp11 except that the crack is in the wrong location. They haven't found the crack but are denying the warranty due to the covered location not being the source. The vehicle only has 93000 miles on it.

Cracked cylinder head/leaking coolant.

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.

. 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 since our car was at the dealership, Mazda would take the lead in submitting the goodwill repair claim (email attached). When we followed up with orland park Mazda, they informed us that no one from Mazda cs had contacted them to authorize the repair. We relayed this to Mazda cs and gave them the direct number of our service advisor, adrian. Mazda cs said they would follow up and get back to us within 48–72 hours. On a follow-up call, I spoke with nancy at Mazda cs, who again told me that our case manager cindy would contact us within 48–72 hours. Instead, we received an email denying the repair, stating the vehicle exceeded the 120,000-mile limit for the extended warranty (our vehicle has 133,500 miles). While our car is outside the warranty period, this is a textbook case of a well-documented defect covered under tsbs for the 2018 cx-9. Mazda has previously approved goodwill engine replacements for other customers well beyond this mileage. We are seeking fairness and consistency in handling known product defects. Our request is that Mazda approve the engine repair under goodwill coverage as they have in many similar cases. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

The vehicle will hesitate/stall while driving down the road. The vehicle has done this multiple times and has actually shut off on 2 different occasions while at a stop. On 2 occasions now the vehicle has not wanted to start. I have taken vehicle to Mazda dealership and they can never duplicate it. When they check for any codes, the vehicle computer does not give accurate times when happened. This last date I took it to them 6/9/25, the computer said it happened 4000 miles ago. The time before, I took it in the morning it happened, 5 min after it happened and the computer said it happened 10 starts ago. The last time, 6/9/25 they said they suspect fuel pump going bad, but until the vehicle gives a "check engine" light or dies all together they are not 100% sure. The vehicle is unsafe if it dies in the middle of the freeway/road with no warning to myself or the other vehicles around me. This has been going on for at least 1 year now, maybe longer dealership has all records. Seeing how the 2018 & 2019 Mazda cx-9 had fuel pump recalls makes me wonder if the 2020 should have been included in this recall. This has been an on going problem. 6/7/25 was most recent incident.

See all problems of the 2020 Mazda CX9 🔎.

The vehicle was overheating and a message came up that power will be reduced. Then it would go away and come up every 3 minutes while driving. I brought it to the service center, we filled it up with coolant and the issue kept coming back this time with a lot of white smoke coming out at vehicle start up. My mechanic said this is a bigger issue most likely to do with a coolant leak at the cylinder head. There is a technical service bulletin but no recall as of yet.

My Mazda has been serviced regularly, in fact my next oil change isn't for 2,000 more miles. I was driving when I heard this weird noise. I looked at the dash and the oil light was flashing and the temperature was over heating. I could also feel the vehicle getting sluggish. I pulled over on the interstate. All the lights were on by this time. I popped the hood and there wasn't any coolant in the resivour anymore. I let the car cool down and I added some water as I was 1 mile from the exit where there was a gas station. I had to baby the car to the exit and shut it off whenever it got hot. The oil was full and seemed overfull even. . . . . Mechanic is guessing the coolant leaked if the engine. . . . I was stranded for hours with 4 children. . .

See all problems of the 2015 Mazda CX9 🔎.

Failed water pump, blown head gasket, major coolant leak, and warped head causing the vehicle to overheat and die when coming to a stop. Vehicle died when stopped in construction on a highway and we were nearly rear-ended. Vehicle never showed check engine light and temperature gauge never showed that vehicle was overheating but significant damage was caused to the engine from “excessive temperatures. ” failure of warning signals allowed us to continue driving the car with a significant engine issue. Now the entire engine needs replaced at only 83,000 miles. Car was diagnosed by licensed independent repair shop. Additionally, front struts went out at approximately 40,000 miles making the car wobble at higher speeds. Was inspected and replaced by dealership.

Car coolant warning light came on for a short time 5 min after starting car, then would go off. During severely cold days it would come on then go off once the car was warm. On 2/25/25 the coolant warning light appeared and stayed on. The car made loud rickety noise, as it warmed up. After driving 2 miles the car coolant light turned red and began blinking. An alert appeared saying car over heating. The car was stopped and smoke came out of the car. The car leaked blue/greenish fluid. Overnight the car cooled. The next day the car continued making loud rickety noise driving to dealership. Dealership would not honor extended warranty for coolant leaks at the cylinder. The water pump cracked, with coolant leak also causing the cylinder to crack and leak oil. Dealership is suggesting total engine replacement. The car has gone through its normal servicing with no reported issues of coolant leak or depletion. The engine overheated in a span of 2 miles after being parked for 8 hours. The car was.

I was driving the vehicle on the highway when the vehicle started to overheat, lights started blinking, the car was smoking, losing power and acceleration. This car has a recall on the cyclindwr head which when cracks causing the car to loose coolant and oil. If it cracks while you’re driving especially on the highway the car will immediately loose coolant and oil thus causing a very dangerous driving condition. There was no indicator prior to the failure that there was anything wrong with the car. No check engine lights, no coolant lights nothing. Prior to this happening I smelled coolant in the car cabin , took it to my mechanic who tested the coolant system and found no leak. At the time he was unaware of the known issue these cars have with the cylinder head. The problem has been confirmed by Mazda and they notified me within the month of March of the problem and the extended warranty to replace the known manufacturer defect cylinder head. The Mazda dealer now has my car and acknowledges the cracked cylinder head caused the problem but said because I didn’t immediately stop on the highway and kept driving until I got to a safe location I was negligent and are refusing to fix the car which now has a blown engine, etc. It is available for inspection now at the Mazda dealer. My safety was put at risk because I could have died on the highway if the car completely stopped working, it was dangerous driving it when it first started happening because it started out of nowhere the car was fine I was driving 50+ mph and it started smoking, overheating etc. I could have also killed someone else. It is a disgrace that not only they won’t fix my car they want to say they won’t because I’m negligent? I drive my kids to and from school everyday do you think I’m going to risk their safety in an unsafe car? they should not only fix the car but compensate me for putting mine and my children’s lives at risk. A complete disgrace.

Excessive oil consumption. In less than 3000 miles, I have to add a quart of oil.

Vehicle experienced coolant leak also oil leak from rear of engine. Broken cylinder head due to turbo too close to head.

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

Coolant leaking from engine block cracked cylinder head.