2017~2022 2.5T Oil Dilution

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2019 CX5 Reserve AWD
Had the oil changed early September. After change checked dipstick, oil was about 1/4" past full. No problem. Then normal suburban driving and long trip, 350 miles each way with about 120 miles in between. Checked oil this morning and it's about 1" past full and slight smell of gas.
Is this concerning? 23,000 miles on odo.
 
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Pueblo county CO
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CX-5 Sport 16.5 6M
Not concerning to me, it's not my car😁.

A thousand miles and you gained maybe a quart? I'd dump that oil right away.
 
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CarpeDiem

Under Pressure
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Superstitions
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2021 CE Turbo
Except that Mazda clearly states in the manual that oil should be checked after the engine is fully warmed up, 5 minutes after shutting down….

Even not “reading the dipstick correctly” wouldn’t show the oil an inch above the full mark. Gas in the oil is not normal, and simply changing the oil won’t fix the problem. Take the CX to a reputable dealer and have them determine where the gas is coming from. If it isn’t fixed they may have to eventually replace the engine - hopefully for the OP before the warranty expires.
 
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2019 CX-5 Signature
Had the oil changed early September. After change checked dipstick, oil was about 1/4" past full. No problem. Then normal suburban driving and long trip, 350 miles each way with about 120 miles in between. Checked oil this morning and it's about 1" past full and slight smell of gas.
Is this concerning? 23,000 miles on odo.
As you're aware from the CR-V forum, this is a byproduct of all DI engines. Just keep an eye on it and maybe get an oil analysis on your next change.
 
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2017 Mazda 6 Sport
Except that Mazda clearly states in the manual that oil should be checked after the engine is fully warmed up, 5 minutes after shutting down….

Even not “reading the dipstick correctly” wouldn’t show the oil an inch above the full mark. Gas in the oil is not normal, and simply changing the oil won’t fix the problem. Take the CX to a reputable dealer and have them determine where the gas is coming from. If it isn’t fixed they may have to eventually replace the engine - hopefully for the OP before the warranty expires.
"at least" 5 min after shutting down. So that the oil has time to drain from the dipstick tube or else it's impossible to get a reading
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Except that Mazda clearly states in the manual that oil should be checked after the engine is fully warmed up, 5 minutes after shutting down….
Except that Mazda clearly states in the manual that oil should be checked after the engine is fully warmed up, AT LEAST 5 minutes after the engine shutting down ⋯

So if I check the oil level 10 hours after the engine shutting down, am I really against Mazda’s recommendation?

The truth is, the oil level showed on the dipstick will be almost the same whether you check it when the engibe is warm, or the engine is cold. You can do it either way you prefer. It’s been proven on my 2.5L. But checking the oil level the first thing in the morning before the engine start is so much easier to see the oil on the dipstick; and just one pull、no wiping required.

Hot:
EFFFC0F2-21FB-4E57-AFA8-605707186B42.jpeg


Cold:
885D4C6F-3D65-4603-988F-7275042D4829.jpeg
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
As you're aware from the CR-V forum, this is a byproduct of all DI engines. Just keep an eye on it and maybe get an oil analysis on your next change.
But the 2.5L on my CX-5, which is a direct injection engine, doesn’t show any sign of oil dilution issue.
 
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2019 CX5 Reserve AWD
Except that Mazda clearly states in the manual that oil should be checked after the engine is fully warmed up, 5 minutes after shutting down….

Even not “reading the dipstick correctly” wouldn’t show the oil an inch above the full mark. Gas in the oil is not normal, and simply changing the oil won’t fix the problem. Take the CX to a reputable dealer and have them determine where the gas is coming from. If it isn’t fixed they may have to eventually replace the engine - hopefully for the OP before the warranty expires.
It was read first thing in the morning after the car sat all night in the garage.
Will check again this weekend after my wife returns from a 70 mile each way trip.
 
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2019 CX-5 Signature
From what I’ve read, Mazda dealers usually treat oil dilution problem on the 2.5T by replacing fuel injectors. But the problem seems to be persistent after the “fix”:

2.5 Turbo - Oil Fuel Dilution Issues?


I’d be worried more about coolant leak issue than the oil dilution issue if I had a 2.5T:

Poll 2.5T Coolant Leak/Engine Replacement. What can be done to prevent?
I'm guessing your 2016 will be your last CX-5. You also think cylinder deactivation will kill all non-turbo 2.5l's. "Doom and Gloom" much? :D
 

sm1ke

Work In Progress..
Moderator
Contributor
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Canada
:
'18 CX-9 Signature
Had the oil changed early September. After change checked dipstick, oil was about 1/4" past full. No problem. Then normal suburban driving and long trip, 350 miles each way with about 120 miles in between. Checked oil this morning and it's about 1" past full and slight smell of gas.
Is this concerning? 23,000 miles on odo.

I would say that it's worth looking into. Get a sample of the used oil during your next oil change, and send it out for analysis. You can also raise the issue with the dealer and/or call Mazda Corporate to get your concern "on paper", but a UoA from a lab is very helpful in proving that there is an oil dilution issue to look into (if oil dilution is present).


I'm guessing your 2016 will be your last CX-5. You also think cylinder deactivation will kill all non-turbo 2.5l's. "Doom and Gloom" much? :D

I'm pretty sure that sentiment isn't limited to non-turbo 2.5Ls, Mazda or otherwise. Anything with CD is problematic, based on post history.
 

erhayes

Contributor
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2021CX5 Reserve
I feel that an UOA is the only way to ascertain if there is excessive fuel in the oil. The smell of fuel in oil is not since a few table spoons in 5 quarts of oil will spell like too much fuel. Lets see UOAs before condemnation. Ed
 
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18 Mazda CX5 AW
Am planning to get a UOA now while under warranty. Just wanted to check on oil test companies... It seems like alot of forum members on this and other sites use/ recommend Blackstone for the UOA. Are there any other good oil analysis firms?
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Am planning to get a UOA now while under warranty. Just wanted to check on oil test companies... It seems like alot of forum members on this and other sites use/ recommend Blackstone for the UOA. Are there any other good oil analysis firms?
sm1ke uses AGAT Lab. There’re a couple of more. In addition to oil dilution, you want to watch the coolant leak issue from the UOA on the 2.5T too. See post #9 for more info.

The most recent UoA from my 2018 CX-9 is attached. The sample was taken at 58500 km.

Potassium levels reported high again.

The lab I used had some logistics issues with receiving/locating my sample, so they didn't charge me for this UoA. Because this one was free, I'll do one more UoA at my next oil change, which will be with the Kirkland 5W-30 instead of the Castrol Edge 5W-30. If the potassium levels remain high, I'll begin actively pursuing a warranty claim for the engine with Mazda. Three independent UoAs with reports of high potassium should be enough to at least get them to take a deeper look at the issue.

Currently the car has 62k, and my next oil change will be at 65k, so I'll re-sample at that time.
 

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sm1ke

Work In Progress..
Moderator
Contributor
:
Canada
:
'18 CX-9 Signature
Thanks @yrwei52. Yes I've used Bureau Veritas in Edmonton AB, and most recently AGAT Labs in Calgary AB. I'm not sure where you're located @Jack Rabbit, but if you're in the US, most people will use Blackstone Labs. With that said, one user here (a CX-9 owner) prefers to use Oil Analyzers instead, especially if you're checking for oil dilution. See post below:

 
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18 Mazda CX5 AW
Thanks @yrwei52. Yes I've used Bureau Veritas in Edmonton AB, and most recently AGAT Labs in Calgary AB. I'm not sure where you're located @Jack Rabbit, but if you're in the US, most people will use Blackstone Labs. With that said, one user here (a CX-9 owner) prefers to use Oil Analyzers instead, especially if you're checking for oil dilution. See post below:

Thanks Sm1ke:

I like the way the AGAT report is easy to read.

Gonna start with Blackstone then maybe get next one by AGAT(if they'll sendy me oil across the border) and then follow up on my 3rd oil change with Oil Analyzers. So I can compare all three over the course of a year.

Thanks again.