2016 Mazda CX-9

2016 Mazda CX-9 2.5L Turbo Touring with 93,197 miles. In September of 2022, I noticed a sweet smell coming from the engine bay after coming home from work. I took my car to my mechanic on 9/30/2022 for an oil change and asked if they could figure out the "sweet smell" coming from the engine bay. When they were doing the oil change, they checked for leaks and noticed that coolant was leaking from cylinder head. Since it was out of warranty, I had my mechanic repair the issue. Which resulted in a complete cylinder head replacement. This is a know issue by Mazda and there is lots of documentation online for this as well. There has since been updated parts to repair this issue, but this should be a recall covered by Mazda. Cause this repair cost me $5,700 out of pocket.

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!

Vehicle “surges” at idle. 300-500 RPMS at a time. Sometimes the brakes hold and sometimes not. Have nearly been in 3 collisions the last 2 days because of this issue. The ECM codes indicate throttle body or TPS issue, both of which have been unfounded. Vehicle has 63,000 miles. Researching this topic online found that many others have had this issue with no associated safety recalls noted. I am hoping to bring light to this so someone doesn’t have to be injured or killed to have this rectified.

Engine is leaking coolant. Took the car to Horne Mazda of Avondale dealership for inspection, was told coolant is leaking from cylinder head. Was told the engine overheated and both cylinder head and cylinder block warped and will need to replace the engine. I feel my safety and others were at risk because the car could have lost power and stalled in the middle of roadway at any time due to there was no symptoms of my car engine overheated, car was running as normal, no check engine light, coolant temperature gauge did not show it was overheating, no sign of engine loosing power, no smoke from under the hood, no sweet smell or any indication engine is loosing coolant and overheating while driving. It appears to be a slow leak because coolant reservoir still have coolant above minimum level. First sign of coolant leak was notice during first week of October 2023 when small amount of green fluid was found on garage floor, took car to dealer on Oct.12.2023 for inspection. MazdaUSA refused to cover engine replacement under paid Mazda Extended Confidence warranty (MEC), blaming it's owners fault for operating car while engine overheated and refused to provide written copy of inspection details.

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.

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.

I have taken the Mazda CX9 since I bought it new to service at Mazda every 6 months or 5,000miles as suggested. Two years a new engine was required due to overheating and coolant problem which the service man noticed 5 months prior during service appointment but didn’t suggest doing anything. Now two years later new engine they installed overheated also.The Mazda has never been in a wreck of any sort. The Mazda has 86,000 miles on it only. How can a car have 2 engines fail in 7 years when it has been serviced there at the agency punctually as required?