Potential damage from overfilled oil on 2018 CX-9

:
2018 CX-9 GT
Just wondering what could be the potential damage from overfilled oil on 2018 CX-9? I changed my oil at dealership I got it from on first week of April. Car has always had excessive smoke coming out of the tail pipes and when I asked about the smoke they said it was normal. Towards late June I had oil change due warning come up even though I had several months left till next scheduled service and not enough mileage elapsed since last oil change. I took it to a different dealer and found other dealer put too much engine oil. All the oil was drained and new oil change done but I am wondering if driving it almost 3 months with too much oil may have caused any long term damage to engine or exhaust system.
 
Define excessive and too much. Video of the smoke? How much oil did they drain out? That's why I change my own oil. And oil reminder will pop out even the mileage is nowhere close. Mazda infotainment system is weird like that
 
Last edited:
Define smoke as well. Oil at dealer ah? Well...
 
If it always had smoke from the exhaust and one oil change was overfilled, then the smoke is a different problem which needs to be found and fixed. To be clear, is the the gray-blue smoke of burning oil?

A slightly overfilled crankcase is no problem. A greatly overfilled crankcase can result in the crankshaft whipping the oil into a foam. Either the crankshaft and other parts can be damaged from hitting the oil, or the oil foam cannot be picked up by the oil pump and a lot of damage happens to oil lubricated parts in the engine.

How high was the overfill?

I'd make an appointment with the dealership you trust the most (or distrust the least) to have them check the smoke. Say nothing about the overfill. It's just about smoke, and demand a definite answer. The exhaust must be clear. If not, you're not meeting the emission laws, and you have a warranty that specifically covers this. You might contact Mazda Canada, 1-800-263-4680, and ask about the smoky exhaust and the emission control requirements. Again, don't mention the overfill. Keep things simple and to the point--the point being the improper smokey exhaust.

Every time you get your car back from service, every time, take a look at what they claim they did. Pull the oil dipstick and check that the oil looks new, clear as water, and the level is correct. If the oil is that clear, you might need to see the level by laying the horizontal dip stick on a paper towel to see where the oil is absorbed. Check the paperwork when you leave the car to be sure they describe the problem, not just list the service writer's guess about what the tech should do. Be sure the paperwork you get back describes the work they did. We get what we inspect, not what we expect. You don't need to be a mechanic to ask the service writer to show you and put their finger on the clean new part that supposedly was replaced or whatever else was done. The first and only time we took our CX9 to the local dealership for an oil change they failed to change the oil or filter. My wife drove the half hour home, I checked the dip stick, and the oil was a half quart low and dirty. I phoned them, spoke with the same service writer, he lied about things until I asked him to check the work order. No oil or filter had been charged to the job. He changed his tune.
 
Last edited:
The smoke was white and would be heavy until engine warmed up. After working up it would go away mostly. I figured since it was still cool outside and my car being parked on driveway, it might be just temperature related. When it didn't go away in June with warm temperatures, I took it to the other dealer and now after this oil change the smoke out of tail pipe is gone. I did call Mazda corporate and they are looking into it.
 
Make sure you get it in writing from the second dealer stating on the service order that they found the oil level to be above than what is required and list the drained amount.
 
Make sure you get it in writing from the second dealer stating on the service order that they found the oil level to be above than what is required and list the drained amount.

Yes they did put it in writing and I did forward that to Mazda corporate. They are currently contacting both service department to get more details.
 
Yes they did put it in writing and I did forward that to Mazda corporate. They are currently contacting both service department to get more details.

If it was indeed blowing smoke, I would at the very least, want the spark plugs to be removed for inspection and if needed, new plugs installed. If the plugs were really bad looking, and the smoke billowing for many miles, then I would be slightly concerned about the catalytic convertors.
(wedge)
 
Last edited:
Yup, what mazdadude said. Assuming the vehicle is now running well and there are no apparent leaks due to excess pressure I'd be concerned about potential damage to the catalytic converter(s). Oil is not kind to them and I understand that it can coat the inner material and it may cause trouble, or perhaps shortened life.
 
Mazda just got back to me indicating the car was overfilled by approximately 1 Liter but they dont think there was any long term damage. They just offered to document the issue in case of future problems and after I insisted they are offering to have the dealer that over filled it check it over again to make sure no issues. Really disappointed they are not getting a different dealer to inspect it since I really don't want to take it back to the place that messed it up to begin with. I really hope this does not cause me expansive out of pocket repair down the road.
 
Mazda just got back to me indicating the car was overfilled by approximately 1 Liter but they dont think there was any long term damage. They just offered to document the issue in case of future problems and after I insisted they are offering to have the dealer that over filled it check it over again to make sure no issues. Really disappointed they are not getting a different dealer to inspect it since I really don't want to take it back to the place that messed it up to begin with. I really hope this does not cause me expansive out of pocket repair down the road.
I have Same car CX9 2017 And my oils smells on petrol .
Did your smells too?
 
Back