2018 Mazda CX-5, 2.5L NA Has been diagnosed with leak in the cylinder head cover, which has resulted in engine oil leaking directly onto the exhaust manifold. This leak produces significant smoke and a strong burning oil smell while the vehicle is running.

There are numerous reports on Mazda owner forums describing the same issue occurring in Mazda CX-5 models. Some owners even reported instances of minor fires or active burning under the hood due to oil contacting hot components.

Mazda released Technical Service Bulletin TSB #SA-031-21, which includes a redesigned cylinder head for the 2018–2019 CX-5 models. This bulletin demonstrates Mazda’s awareness of the design flaw.

There is substantial evidence that this is a widespread defect in these model years, unrelated to owner misuse or vehicle mileage. Mazda should take full responsibility by issuing a formal recall or providing an extended warranty to address the problem and prevent safety risks.

My 2018 CX-5 has 40,000 K/M on it and is 18 months old. I am the original owner and have performed regular maintenance on the vehicle.

I took the CX-5 to the dealership I bought it from for its 40K oil change and did not drive it for two days. The first day my wife took the vehicle to work she smelled something burning. No dashboard warning lights came on at the time. When she arrived home at the end of the day she told me about the smell and I checked it out. The following is what I found:

-The car had a strong smell of burning oil, much stronger than the smell of oil after an oil change. -There was oil on my driveway -There were oil patches on the road coming from the direction she drove -There was oil in my garage in the spot that she had parked the last 2 days that I had not previously noticed.

I took the car to the dealership to have it looked it. When I got to the dealership, which is 5 minutes from my house, no warning lights came on but smoke was coming from the engine and from underneath the hood. The dealership kept the car overnight and gave me a loaner vehicle. The dealership informed me the next day that they washed the oil that was sprayed/splattered at the top of the engine so that they could see where the leak was coming from. Based on what the mechanics observed they reported that the cause of the issue was a "defective Head Cylinder that some CX-5's with certain VIN # have had issues with". The head mechanic reported to me that the "Head Cylinder was defective and that the fresh thinner oil may have made it easier for the oil to escape/leak".

In speaking with the Service Manager I was told that Mazda Canada had instructed them that the fix for the issue is the following:

-Replacement of the Head Cylinder -Replacement of the Head Gasket -Replacement of some seals -Replacement of some "associated parts".

I asked for the diagnostic or mechanics report on the vehicle a few times but the service department refused to provide me with anything written. I asked about an extended warranty and they said that would not be possible. The Service Manager told me that these "vehicles are mass produced and sometimes there are issues like this". I now have an 18 month old car that I have paid a lot of money for that will have its engine rebuilt in the dealerships service department. If I knew this would happen with this vehicle I would not have purchased a CX-5 from Mazda and gone in another direction.

I have been in touch with Mazda Canada and they have given me a file number. They will be following up with the dealership and will be in touch with me.