2021 CX-9 Burning oil

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Northeast
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2020 CX-5 Tour
... This means Mazda hasn’t figured out what happened to this oil burning issue on these 2021 2.5T’s. ...

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.
 
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Pueblo county CO
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CX-5 Sport 16.5 6M
You could also record the event in your maintenance log. You could take a pic of the dashboard if you feel you need proof, although if you do have a serious defect you should have ample time to address the issue under warranty.

On the other hand if you drive the vehicle with a low oil level and you cause wear or damage you might be violating the terms of the warranty; for example if the manual stipulates that you should add oil in case of low oil level.

Despite anecdotes about engines that survived a low oil condition, some engines have been known to suffer serious valve train damage if run low, although the damage might not show immediately. I wouldn't want to risk cooking a turbo bearing or anything else just to prove my car consumed a quart in 6k miles. After all Mazda might not consider it excessive.
 
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You could also record the event in your maintenance log. You could take a pic of the dashboard if you feel you need proof, although if you do have a serious defect you shoild have ample time to address the issue under warranty.

On the other hand if you drive the vehicle with a low oil level and you cause wear or damage you might be violating the terms of the warranty; for example if the manual stipulates that you should add oil in case of low oil level.

Despite anecdotes about engines that survived a low oil condition, some engines have been known to suffer serious valve train damage if run low, although the damage might not show immediately. I wouldn't want to risk cooking a turbo bearing or anything else just to prove my car consumed a quart in 6k miles. After all Mazda might not consider it excessive.
This is what I was thinking, too. I have the alert in my app, and I’ll take a picture of the dipstick and dash before I add oil just to CMA.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
*regarding capacity, if you notice the manual specifically states to check the oil you want to get the car up to operating temperature, then wait at least 5 minutes. What you'll notice is the oil level will read higher doing it this way vs cold. I think that could be why they call for 5.1qts. 5.1qts when checked cold could read slightly lower than the top hole, but if you check it 5 or so minutes after the car has been driven, you may find it to reach that hole. Try that.
Yes I tried although it’s on a 2.5L of my CX-5 and here are the fact:

Hot:
C3A1CD65-2956-4BBC-9755-2E3B91EE3D44.jpeg


Cold:
9A279BB4-14DB-499E-85BA-EA2E8537B726.jpeg


The difference is minimum. The manual only says wait AT LEAST 5 minutes so that more oil can drain back to the oil pan, it doesn’t say the oil has to be hot or cold, or can’t wait for longer time such as overnight for much easier reading on dipstick. The longer you wait, more oil will drain back to oil pan, which compensates the thermal expansion on warm oil. As you can see, the result on taking oil level between hot and cold is almost the same.

About the approximate (I call it “inaccurate and “inconsistent”) 5.1 quarts of oil capacity on the 2.5T, the same thing happens on specs for the 2.0L and 2.5L. If you put in said oil change amount and the oil level will only be at ½ ~ ⅔ between Min / Add and Max / Full marks on dipstick depending on how long you drain the oil, or if you have a Fumoto® drain valve (which can’t drain the oil completely). If you prefer the oil level to be at the Max / Full mark after the oil change for better safety margin, about 0.4 quart more than specified oil amount is needed.
 
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Pueblo county CO
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CX-5 Sport 16.5 6M
I just drained the oil from my '16 2.0L after a short trip thru Moab and southern Utah. There are less than 5000 miles on this oil but a year has gone by. I always put about 5 qts in. I also pour some oil into the new filter.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
I just drained the oil from my '16 2.0L after a short trip thru Moab and southern Utah. There are less than 5000 miles on this oil but a year has gone by. I always put about 5 qts in. I also pour some oil into the new filter.
And Mazda says in the manual that the 2.0L needs 4.4 quarts for oil and oil filter replacement ⋯ 🤔

I put 5.25 quarts for oil change on my 2.5L even though the spec says 4.8 quarts. I always want the oil level to be at the Full mark after the oil change for better safety margin.
 
On my last 2.5L the cold level was slightly below the top hole, while the hot was exactly at full.

Sometimes, it does matter. For example, with the Cadillac Northstar engines (at least the FWD versions), if you filled the sump (which is 7.5-8 quarts) to the full level cold, and you went to measure it hot, you'd be "overfilled" by about half a quart. Folks would complain about excessive oil usage because they kept topping the oil off cold. When recommended to keep the oil at the full line, when hot, oil usage would suddenly not be there anymore. Full when hot is typically about half a quart "low" when cold. As noted above, it just depends on how the dipstick is calibrated.
 
Taken from BITOG:

Sequence:
  • Run to operating temperature. Turn off.
  • Check level after 2 minutes.
  • Check level after 5 minutes.
  • Check level after 30 minutes.
  • Check level after 60 minutes.
  • Check level after 90 minutes.
  • Check level after 480 minutes (i.e. overnight).
Results: Minutes since off: Level*
  • 2 minutes: 2/5
  • 5 minutes: 3/5
  • 30 minutes: 3/5
  • 60 minutes: 3/5
  • 90 minutes: 4/5
  • 480 minutes: 4/5
* Level = distance between L (low) and F (full) marks; I chose 5ths to give a reasonable level of granularity Conclusions: The difference between the lowest reading and the highest reading is 2/5, or 40%, of the distance between L and F marks. Per the OM, the distance between those marks represents approximately 0.7 quart (yes, it states just that). To be more conservative and simplify the math, I bump this to 0.75 quart. This means that 40% of the 0.75 quart is about 10 oz. Per the OM, the oil capacity, with filter, is 3.8 quarts. Thus, 10 oz. is 8% of the total capacity in this application. Since the OM specifies checking at operating temperature and "a few minutes" after engine off and to give the dipstick handle a chance to to cool down some from the piping hot exhaust manifold, I think I'll adopt the approach of checking it 30 minutes after engine off and make that my new practice.
 
Yes I tried although it’s on a 2.5L of my CX-5 and here are the fact:

Hot:
View attachment 305245

Cold:
View attachment 305246

The difference is minimum. The manual only says wait AT LEAST 5 minutes so that more oil can drain back to the oil pan, it doesn’t say the oil has to be hot or cold, or can’t wait for longer time such as overnight for much easier reading on dipstick. The longer you wait, more oil will drain back to oil pan, which compensates the thermal expansion on warm oil. As you can see, the result on taking oil level between hot and cold is almost the same.

About the approximate (I call it “inaccurate and “inconsistent”) 5.1 quarts of oil capacity on the 2.5T, the same thing happens on specs for the 2.0L and 2.5L. If you put in said oil change amount and the oil level will only be at ½ ~ ⅔ between Min / Add and Max / Full marks on dipstick depending on how long you drain the oil, or if you have a Fumoto® drain valve (which can’t drain the oil completely). If you prefer the oil level to be at the Max / Full mark after the oil change for better safety margin, about 0.4 quart more than specified oil amount is needed.
I completely agree. This what I've found in my previous 2.5 as well.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Taken from BITOG:

Sequence:
  • Run to operating temperature. Turn off.
  • Check level after 2 minutes.
  • Check level after 5 minutes.
  • Check level after 30 minutes.
  • Check level after 60 minutes.
  • Check level after 90 minutes.
  • Check level after 480 minutes (i.e. overnight).
Results: Minutes since off: Level*
  • 2 minutes: 2/5
  • 5 minutes: 3/5
  • 30 minutes: 3/5
  • 60 minutes: 3/5
  • 90 minutes: 4/5
  • 480 minutes: 4/5
* Level = distance between L (low) and F (full) marks; I chose 5ths to give a reasonable level of granularity Conclusions: The difference between the lowest reading and the highest reading is 2/5, or 40%, of the distance between L and F marks.
Good info. But for the Mazda 2.5L on my CX-5, the difference between hot and cold on oil level is almost nothing with pictures to prove.

Per the OM, the distance between those marks represents approximately 0.7 quart (yes, it states just that). To be more conservative and simplify the math, I bump this to 0.75 quart.
According to Mazda, the oil amount between Min / Add and Max / Full on dipstick is 1L / ~1 quart like everybody else. This’s from 2021 CX-9 owner’s manual:

A44CAA5D-BFBF-4829-827E-5955BDF3FBDB.jpeg



9DA2342A-4FC6-4678-B7DF-363B15FF772D.jpeg
 
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Kedis82ZE8

'12 GX 460,'07 G35x / '15 CX-5 AWD GT w/Tech Pkg
Contributor
Following... I have had my leaks in the past but nothing that ever caused noticeable drop on dipstick on my '15 CX-5 w/2.5... even to this day......

Sympathetic to concern... this kind of thing tears at me!!!
 
Got it in to the dealer for an oil change today, service manager agreed it wasn’t cool to go through a quart in 6300 miles. They found no evidence of leaks. He actually suspected it wasn’t completely filled to begin with, so the amount lost or burned wasn’t a full quart. It’s on record that it happened and we’ll monitor it more closely from here out. They were nice enough to grab a sample of the used oil for me to send out too.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Got it in to the dealer for an oil change today, service manager agreed it wasn’t cool to go through a quart in 6300 miles. They found no evidence of leaks. He actually suspected it wasn’t completely filled to begin with, so the amount lost or burned wasn’t a full quart. It’s on record that it happened and we’ll monitor it more closely from here out. They were nice enough to grab a sample of the used oil for me to send out too.
Actually based on many 2.5T owner’s observation, the 2.5T usually is over-filled from factory. But the 2.5L NA on CX-5 usually is under-filled by ~0.3 quart to the Max mark from factory.

I do oil change by myself. But I also have no problem to ask service advisor to save some old factory oil and oil filter for me on the first oil change by a Toyota dealer on my 2018 Toyota Yaris iA (Mazda2 in disguise) as Toyota offers free 2-year maintenance for all new vehicles.
 

dynamho

Member
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02Protege 06RX8
:
17M6GT 21CX5sig
As an RX-8 owner and a 21 year old Protege, topping up small amounts of oil loss is a trivial routine. Not even an issue. ;)

I hope no one is being anal about oil level measurement and then getting the car oil changed at a dealer. That's contradictory. The dealer techs, at least in my area (high density urban), have a tendency to overfill because they don't want to spend the time to check levels and just go by spec tables.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
As an RX-8 owner and a 21 year old Protege, topping up small amounts of oil loss is a trivial routine. Not even an issue. ;)
Using oil is the nature of the beast on rotary engines.


I hope no one is being anal about oil level measurement and then getting the car oil changed at a dealer. That's contradictory.
No, we’re all DIYers ⋯ ;)


The dealer techs, at least in my area (high density urban), have a tendency to overfill
Yes, this’s so true!


⋯ because they don't want to spend the time to check levels and just go by spec tables.
No, this’s not true for most Mazda vehicles. If the tech go by the specs, they put in 5.1 quarts for the 2.5T、4.8 quarts for the 2.5L NA、and 4.4 quarts for the 2.0L NA, all will be “under-filled” by 0.4 ~ 0.5 quarts (to the Full / Max mark of the dipstick)!
 

dynamho

Member
:
02Protege 06RX8
:
17M6GT 21CX5sig
No, this’s not true for most Mazda vehicles... all will be “under-filled” by 0.4 ~ 0.5 quarts (to the Full
I'm guessing their flow meters aren't calibrated as often as they should. And there's less risk for them with overfilling than underfilling?

Reminds me of those folks filling up with gasoline until the dispenser clicks and then topping it off to the brim. :LOL:
 
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2021 CX-9 Sig
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2021 CX-5 GT
Following... I have had my leaks in the past but nothing that ever caused noticeable drop on dipstick on my '15 CX-5 w/2.5... even to this day......

Sympathetic to concern... this kind of thing tears at me!!!
This is really specific to the 2.5T. Not the 2.5NA.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
I'm guessing their flow meters aren't calibrated as often as they should. And there's less risk for them with overfilling than underfilling?
This doesn’t make sense to me though, if the dealer uses bulk oil and the flow meter is off that much, and seems always overfill? In theory the dealer should always try to give you less oil from oil drum to save some money?

My theory is the tech doesn’t give the engine enough time to drain old oil completely, and uses different oil capacity spec from car manufacture for oil change.

When I questioned the oil change which was overfilled, the tech at Toyota dealer told me Toyota gives them 4.6 quarts on oil change quantity for my 2018 Toyota Yaris iA (Mazda2 in disguise), not the 4.4 quarts said in the owner’s manual. But when I changed the oil on Yaris by myself last week since Toyota’s 2-year free new car maintenance is done, I found 4.6 quarts is legit, not 4.4 quarts said in the manual. Apparently those techs simply didn’t drain the oil completely which caused overfill.
 
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2021 CX-9 Sig
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2021 CX-5 GT
So, I am scheduled to get my oil changed today. The car has 5039 miles from the last oil change. At the start, the oil was slightly above the top hole. This is it this morning.

IMG_9745 copy.jpg