2021 CX-9 burning oil

jean-luc

2021 CX-9 Signature
I'm glad this oil burning issue has been confirmed and acknowledged by Mazda (at least). Let's just hope they give us a permanent solution by next year.
 
:
RDX Aspec Adv.
This TSB only applies to 2021 vehicles. Your 2018 CX-9 is not impacted by this in any way and that is the main reason your car does not burn oil. It most likely has nothing to do with the type of oil.

As for the 2021 models, there is no fix yet. And I would think there may not be one in the short term. I would also bet that if there are engine failures they will deal with them on a case by case basis - like they are doing with the coolant issue. Personally, I am hesitate to keep this long term and will most likely trade it in for something else within a year or two.
Why is there "no fix" if the issue is only indicated in VIN BEFORE a certain date? What was done different AFTER said date to prevent this...because that sounds like "the fix", yeah?
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Why is there "no fix" if the issue is only indicated in VIN BEFORE a certain date? What was done different AFTER said date to prevent this...because that sounds like "the fix", yeah?
edmaz said it the best from post #41:

Actually, Mazda is talking out of both sides of their mouth in this TSB. First they wrote: 'The root cause of this concern has not been identified yet'; but then immediately follow that up with: 'Since this issue has been reported after a valve stem seal modification, it is very likely that valve stem seal damage is causing oil to leak into the combustion chamber'.

This almost sounds like they changed their mind on what to provide for the reason, and then didn't edit out the original statement. However, it seems likely IMO the information about the stem seals is correct, and this will eventually be flagged as the root cause. I also think Mazda's real problem with this is deciding which repair to make. Same old story - do they trust their stealerships to do the significant engine repair, or are they just going to do the simpler (but probably more costly) engine swap.

Can't help wondering if Mazda is going to start to buckle under the weight of their various major engine issues - the ones we're aware of, and also what may still be yet to come.
 

jean-luc

2021 CX-9 Signature
So back in 10/02/2021 (9456mi) when I went to the dealer to report the oil consumption, all they did was to give me lame excuse about the engine being "new" and they just changed the oil and top it off. Oil level was right above the FULL mark.

I'm @ 15056mi now, after 4 months, so I changed my oil today and the oil level is almost at the low level.

20220205_103925[1].jpg


Poured in an entire 5qt jug after I installed the pre-filled oil filter.

20220205_111647[1].jpg


Topped it off to avoid future low oil warnings in the next 5k miles or so.

20220205_112057[1].jpg


I hope Mazda issues a solution to this oil burning issue sooner than later.
 
:
RDX Aspec Adv.
So back in 10/02/2021 (9456mi) when I went to the dealer to report the oil consumption, all they did was to give me lame excuse about the engine being "new" and they just changed the oil and top it off. Oil level was right above the FULL mark.

I'm @ 15056mi now, after 4 months, so I changed my oil today and the oil level is almost at the low level.

View attachment 307215

Poured in an entire 5qt jug after I installed the pre-filled oil filter.

View attachment 307216

Topped it off to avoid future low oil warnings in the next 5k miles or so.

View attachment 307217

I hope Mazda issues a solution to this oil burning issue sooner than later.
This is pushing me hard to look at the Acura RDX A-spec advance. I have a test drive next week weather permitting.
 
From bottom hole to top hole is 1QT oil. Burning less than 1 QT in 5500 miles may seem like a lot to us but to ANY manufacturer it is not an issue and considered normal with today's low tension piston ring engines.
 
:
RDX Aspec Adv.
From bottom hole to top hole is 1QT oil. Burning less than 1 QT in 5500 miles may seem like a lot to us but to ANY manufacturer it is not an issue and considered normal with today's low tension piston ring engines.
Killed a catalytic converter doing this in about 70k miles on my ws.6.
 
:
2021 CX-9 Sig
:
2021 CX-5 GT
So back in 10/02/2021 (9456mi) when I went to the dealer to report the oil consumption, all they did was to give me lame excuse about the engine being "new" and they just changed the oil and top it off. Oil level was right above the FULL mark.

I'm @ 15056mi now, after 4 months, so I changed my oil today and the oil level is almost at the low level.

View attachment 307215

Poured in an entire 5qt jug after I installed the pre-filled oil filter.

View attachment 307216

Topped it off to avoid future low oil warnings in the next 5k miles or so.

View attachment 307217

I hope Mazda issues a solution to this oil burning issue sooner than later.

That sucks. I have been keeping an eye on my oil as well. For me, the oil use seems to have stabilized. Still slightly above the top hole. Sorry for the dark pictures. The oil is also still clean and can best been seen right at the top hole.

I see that you are close to 6000 miles from the last oil change. MY feeling was that the oil level dropped significantly after 4000 miles. My dealer said the same thing. So, I showed them the TSB and even printed it out and gave them a copy. They are doing 5000 mile oil changes now as well.
 

Attachments

  • Oil level CX-9.pdf
    499.5 KB · Views: 74
Last edited:
:
2021 CX-9 Sig
:
2021 CX-5 GT
So, I am now at close to 4300 miles and just finished a 600 mile trip up the east coast. Beside averaging ~26 mpg I am happy to say, my oil level appear to be holding steady. Sorry for the bad pics, for some reason, todays picture came out much nicer! But basally, I can say that for some reason, the oil level has remained pretty much the same over 4300 miles.


Oil level CX-9.jpg
 
:
2018 Mazda CX-9 Grand Touring / Deep Crystal Blue / Sand leather
This is pushing me hard to look at the Acura RDX A-spec advance. I have a test drive next week weather permitting.
At the end of the day, do what you want, but coming from someone who's gone through more cars than they should have: Make sure your car purchasing decision is made from the perspective of "running towards" something you truly want or like, not "running away" from a car that, for example, you're worried about having reliability issues with (all cars have them of course, more on that below).

I believe the RDX is a great SUV. Heck, I have a 2021 Acura TLX now (SH-AWD has been awesome this winter, btw) so my assessment of the RDX is based on my own biased opinion (my parents also have a 2016 RDX). That said, if you were to take a look at the RDX subforum over at Acurazine, you'd think everyone's rear hatch windows were exploding and that if you were to get an RDX, yours inevitably would too.

So getting back to my original point: Are you driven more by your desire to "run towards" the RDX because you really, really want one or are you more driven by the reliability concerns with the 2.5T being discussed in this thread?

Odds are most people will be fine and the issue will only affect a small number of users and hopefully be addressed before it affects more. Being Captain Obvious here, but I think we can generally agree that forums are not usually the best place to get an idea of a particular car or brand's reliability. You can get an idea, sure, but people are much more likely to go through the effort of going online, finding a forum, registering, and writing up a post to seek help and/or complain about issues than to simply say, "everything's been awesome" (though some do and I like to see it).

As for why I'm here even though I have an Acura now: I used to have a CX-9 (it was awesome) and I was just randomly stopping by and seeing how things were going, hahah. I'm keeping a close eye on the new CX-70/CX-90 due out in the next couple years and that rumored sports sedan (all with an inline 6 engine being an option, hopefully) for when my lease on the Acura ends too.
 
:
RDX Aspec Adv.
At the end of the day, do what you want, but coming from someone who's gone through more cars than they should have: Make sure your car purchasing decision is made from the perspective of "running towards" something you truly want or like, not "running away" from a car that, for example, you're worried about having reliability issues with (all cars have them of course, more on that below).

I believe the RDX is a great SUV. Heck, I have a 2021 Acura TLX now (SH-AWD has been awesome this winter, btw) so my assessment of the RDX is based on my own biased opinion (my parents also have a 2016 RDX). That said, if you were to take a look at the RDX subforum over at Acurazine, you'd think everyone's rear hatch windows were exploding and that if you were to get an RDX, yours inevitably would too.

So getting back to my original point: Are you driven more by your desire to "run towards" the RDX because you really, really want one or are you more driven by the reliability concerns with the 2.5T being discussed in this thread?

Odds are most people will be fine and the issue will only affect a small number of users and hopefully be addressed before it affects more. Being Captain Obvious here, but I think we can generally agree that forums are not usually the best place to get an idea of a particular car or brand's reliability. You can get an idea, sure, but people are much more likely to go through the effort of going online, finding a forum, registering, and writing up a post to seek help and/or complain about issues than to simply say, "everything's been awesome" (though some do and I like to see it).

As for why I'm here even though I have an Acura now: I used to have a CX-9 (it was awesome) and I was just randomly stopping by and seeing how things were going, hahah. I'm keeping a close eye on the new CX-70/CX-90 due out in the next couple years and that rumored sports sedan (all with an inline 6 engine being an option, hopefully) for when my lease on the Acura ends too.
You're absolutely correct.

I was into the CX5, although I was not huge on the AWD system, it is pretty good, but the RDX was just a bit more, in every way. The SH-AWD, the adjustable dampers, etc. were what pushed me. Supposedly the rear windscreen issue is fixed. That said, Acura sells 50-60K RDX's per year, and if a couple hundred have broken so far, that's still within the realm of "there was a bad batch/process" and not something I am super stressed about. The oil usage is a TSB with no resolution per Mazda. THAT is concerning. Also...rear windscreen>engine when it comes to replacement. Again though, it was the whole package, not just this one issue.
 
:
2018 Mazda CX-9 Grand Touring / Deep Crystal Blue / Sand leather
You're absolutely correct.

I was into the CX5, although I was not huge on the AWD system, it is pretty good, but the RDX was just a bit more, in every way. The SH-AWD, the adjustable dampers, etc. were what pushed me. Supposedly the rear windscreen issue is fixed. That said, Acura sells 50-60K RDX's per year, and if a couple hundred have broken so far, that's still within the realm of "there was a bad batch/process" and not something I am super stressed about. The oil usage is a TSB with no resolution per Mazda. THAT is concerning. Also...rear windscreen>engine when it comes to replacement. Again though, it was the whole package, not just this one issue.
Gotcha - makes sense. Again, I agree the RDX is awesome. As of right now, I've got it on my radar if I decide to move away from a sedan when my lease is up too.

I hope I didn't come off as not believing you were capable of making the decision yourself, I didn't mean it that way. I meant to just throw out some wisdom that I wish I had when I made some of my previous car purchasing decisions. 😅

For what it's worth, I've had a couple VWs that consumed oil (one of them consumed a quart every ~1k miles) and ultimately had no other concerning issues with them. There otherwise aren't any broader oil consumption issues that I'm aware of with the Honda/Acura 2.0T. I wouldn't be surprised if some consumed oil to an extent though. I only have ~3700 miles on my TLX and the oil "health" indicator shows ~60% life remaining. I admittedly haven't checked the dipstick to see if any has been consumed.

Anyway, good luck with your search/decision! Based on my experience, Acura and Mazda make great vehicles and neither are without their quirks issues but I believe that a buyer in the market couldn't go wrong with either. Comes down to preference and their own requirements.
 
Last edited:
:
2021 CX-9 Sig
:
2021 CX-5 GT
What would make the oil level be pretty good until roughly 4500-5000 miles? This is my oil level examination over 5000 miles. Up to 4300 miles, it looked good. A long drive south and at 5000 miles, it has gone from being right above the top hole to right in between the two. That is why if you try to do the 7500 mile oil change, it will not work. Everything will look good until 5000 miles and will go downhill after that.
Oil level CX-9 at 5K.jpg
 
:
Pueblo county CO
:
CX-5 Sport 16.5 6M
There could be several explanations. What if you had been consuming oil but it was replaced with gas? Then a long drive could heat up the oil and boil off the gas.

But I think it's just as likely that the long drive just aspirated the oil. I think there is a tendency for that to happen and the reason you check your oil more frequently when traveling.

You could just add a pint now and it could last to 7500. Or just change it. I would wait until it's warmer as it's almost March now.