2021 CX-9 Burning oil

[edmaz]

The oil sensor is fine except that its set way way too high. The thing chimes at like 4 qts. Should be 2.5 to 3 like every other car out there

The oil sensor that's being referenced in this thread is the oil level sensor - yellow warning light, and is triggered when the level is just shy of one quart down. The (red warning light) oil pressure sensor is likely triggered somewhere around the 2.5-3 quart level that you mentioned.

IMO, if there's an oil level sensor installed in addition to the oil pressure sensor, then triggering it at 1 quart low is just about right. For the very few owners who regularly check their oil (such as most of the people on this board), we will never come close to ever seeing this light come on, UNLESS there is a major oil leak. And if that did ever happen, the yellow warning light coming on would likely give an alert driver time to get off the road and shut down, before any engine damage happens.

And for the great majority of owners, who never check their oil, the low oil level warning is a true idiot light, and also a really great tool for mitigating the impact of systemic issues such as this one with the 2021 Turbo.

 

[BinTom]

This seal replacement is not rocket surgery. I have done this procedure on similar engines. It tedious, and you need to take your time but not difficult. And it’s pretty hard to botch it. But yours isnt the first one thats gone south after the fix. If done correctly, and with new valve seals the 2021 is rock solid.

Shop foreman said it might have been faulty parts. Who knows. Hopefully all fixed now.

 

[ctbale]

The oil sensor that's being referenced in this thread is the oil level sensor - yellow warning light, and is triggered when the level is just shy of one quart down. The (red warning light) oil pressure sensor is likely triggered somewhere around the 2.5-3 quart level that you mentioned.

IMO, if there's an oil level sensor installed in addition to the oil pressure sensor, then triggering it at 1 quart low is just about right. For the very few owners who regularly check their oil (such as most of the people on this board), we will never come close to ever seeing this light come on, UNLESS there is a major oil leak. And if that did ever happen, the yellow warning light coming on would likely give an alert driver time to get off the road and shut down, before any engine damage happens.

And for the great majority of owners, who never check their oil, the low oil level warning is a true idiot light, and also a really great tool for mitigating the impact of systemic issues such as this one with the 2021 Turbo.

I was looking at it from Mazda's point of view. Having that oil level light go off at approx 4 quarts has to have generated lots and lots of inquiries from the "idiots". But I like it. Like you say, if the drain plug comes out, or it starts dumping oil it's gives you time to get it to the side of the road before the oil pressure lite illuminates. Most oil pickups are less then an inch off the bottom of the pan so if the car is not rockin and rolling your going to have pressure all the way down to 1.5 quarts. Definitely 2 quarts. Not where I would want my oil level though. I never check my oil. I put in 5.5qts with the filter. 5000 miles later I drain out almost 5.5qts and do it all over again. The yellow light will advise if I need to know anything

 

[wineng]

Had the low oil light come on at 42k KM and put a quart in. Brought it to the dealership and I pretty much had to force them to look up the TSB as they said it was normal. They wanted to do an oil consumption test so I brought it back every 2000 km for a couple of times. Both times the loss was over a quart. They replaced the seals (Part#PY8W-10-1F5) and no more oil loss so far after about a month of driving. All covered under warranty.

 

[ctbale]

Had the low oil light come on at 42k KM and put a quart in. Brought it to the dealership and I pretty much had to force them to look up the TSB as they said it was normal. They wanted to do an oil consumption test so I brought it back every 2000 km for a couple of times. Both times the loss was over a quart. They replaced the seals (Part#PY8W-10-1F5) and no more oil loss so far after about a month of driving. All covered under warranty.

Its bs them making 21 owners do consumption tests. Pisses me off. It doesn't say to do that in the tsb.

 

[BigfurMN]

21 Signature just had the light come on in mine the other day and then it went out. A few days later came on again and went out again after shutting off the car and restarting it. Checked the stick and it was barely registering on the stick. Added a quart that seemed to top it off. Going to keep an eye on it. First time it has happened and I am at about 32K on it. Not happy about it but bought a 6 pack of Mobile 1 just in case.

 

[Silly Wabbit]

21 Signature just had the light come on in mine the other day and then it went out. A few days later came on again and went out again after shutting off the car and restarting it. Checked the stick and it was barely registering on the stick. Added a quart that seemed to top it off. Going to keep an eye on it. First time it has happened and I am at about 32K on it. Not happy about it but bought a 6 pack of Mobile 1 just in case.

How many miles into your last oil change? I think this is very crucial.

 

[BigfurMN]

True I am at about 8k since the last change.

 

[ctbale]

21 Signature just had the light come on in mine the other day and then it went out. A few days later came on again and went out again after shutting off the car and restarting it. Checked the stick and it was barely registering on the stick. Added a quart that seemed to top it off. Going to keep an eye on it. First time it has happened and I am at about 32K on it. Not happy about it but bought a 6 pack of Mobile 1 just in case.

Sorry, but I gotta ask, why did you add oil, and do you know about the TSB?

 

[BigfurMN]

I was not aware of the TSB until today. I added oil as it wouldn’t leave me stranded with a 3yo if sh*t really went south.

 

[ctbale]

We

I was not aware of the TSB until today. I added oil as it wouldn’t leave me stranded with a 3yo if sh*t really went south.

Well then, delete your posts, drain out 2 quarts (car can run all day long on 3) let that code set, take it to the dealer and get those bad seals replaced with good ones so you don't plug up your cat, or gum up your pistons with all that oil going thru that poor poor engine!!

 

[gphin]

Am I missing something? You used one quart of oil over 8k miles since your last change and you think you have an oil consumption problem?

 

[ctbale]

Am I missing something? You used one quart of oil over 8k miles since your last change and you think you have an oil consumption problem?

It's a 21, if it doesn't have oil consumption issues now, it will later........

 

[yrwei52]

I was not aware of the TSB until today. I added oil as it wouldn’t leave me stranded with a 3yo if sh*t really went south.

I agree with @ctbale. You shouldn’t add any oil. You want to keep the Low Oil Level Warning Light lit, and show it to you Mazda dealer with the TSB to replace those bad exhaust valve stem seals. Amber / yellow warning lights mean the engine isn’t in critical situation and it’s fine to drive the car for a while. Any red warning lights, such as the Low Oil Pressure Warning Light, is a different story.

Now since you have added the oil, you really want to watch the Low Oil Level Warning Light lit again between oil changes, and try to get those bad exhaust stem seals replaced on your 2021 CX-9 Sig. while you still have warranty.

 

[yrwei52]

It's a 21, if it doesn't have oil consumption issues now, it will later........

Exactly! Better to have those bad exhaust stem seals replaced while it still has warranty.

 

[dunhillmc]

Also, you're overdue for an oil change. You don't want to give Mazda an excuse to not cover the fix/repairs

 

[yrwei52]

True I am at about 8k since the last change.

If you’re at 8K miles (not km) since the last oil change, you’d better change your oil ASAP as the maximum interval for oil change on the 2.5T is 7,500 miles or 12 months. Yes, you really don't want to give Mazda an excuse not to cover the valve stem seal replacement.

 

[ctbale]

If you’re at 8K miles (not km) since the last oil change, you’d better change your oil ASAP as the maximum interval for oil change on the 2.5T is 7,500 miles or 12 months. Yes, you really don't want to give Mazda an excuse not to cover the valve stem seal replacement.

Thats a really good point. I wouldnt let the dealer get any clue the oil in there is even 1 mile past 7,500 old. No way 8k oil would doom those seals, but I wouldnt risk them ever knowing. I would fake up some paperwork that I supliment dealer oil changes with dyi oil changes or something. And yes everbody, dyi oil changes are legal! Haha

 

[PTguy]

It took more than 8000 miles without an oil change to destroy this engine, but without oil changes this always happens. No warranty nor extended warranty nor manufacturer goodwill will repair this. Change the oil every 7,500 miles with top quality oil (it doesn't need to be synthetic) and quality oil filter, or every 3,000 miles with cheapo oil and filter.

 

[yrwei52]

It took more than 8000 miles without an oil change to destroy this engine, but without oil changes this always happens. No warranty nor extended warranty nor manufacturer goodwill will repair this. Change the oil every 7,500 miles with top quality oil (it doesn't need to be synthetic) and quality oil filter, or every 3,000 miles with cheapo oil and filter.
View attachment 323724

IMO 8,000 miles won’t destroy an engine like the picture showed unless a really crappy non-synthetic oil was used.

Remember Toyota has been using 10,000-miles OCI for the last many years, and with a super-thin 0W-16 oil.

UOA from Blackstone Lab frequently suggested the used oil still has another thousand mile of service life after 7,500 miles on CX-5’s 2.5L NA.