2015 CX-5 2.5 SkyActiv coolant in oil

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2015 CX-5 GT
At 88k miles, Blackstone report suddenly shows 10x normal level of Sodium and nearly 100x Potassium - clearly, coolant in oil. I have searched the internet and cannot find any other mention of this situation in the 2.5 SkyActive engine. Of course, with 13:1 compression the first suspect is the head gasket. However, there are no bubbles emanating from the radiator and the chemical (block) test shows no evidence of combustion gases in the coolant. The next thought for any engine would be the oil cooler, but this engine doesn't have one. I'm familiar with the water pump issues from (completely different, Ford-sourced) Mazda engines but the exploded view in TSB01-022/19 (https://static.nhtsa.gov/odi/tsbs/2019/MC-10169537-0001.pdf) seems to make this pump an unlikely source for transfer into oil.
Does anyone have experience with this situation, in this engine?
Since many are probably wondering....no expense has been spared in the care of this engine - always 89 Octane to mitigate possible detonation and 5k oil changes (not every one analyzed) with LiquiMoly SpecialTecAA 5w30. Spark plugs replaced at 71k.
Blackstone report shows no damage yet, but I'm keenly aware of the seriousness of this condition. I've already changed the oil again after only 2600 miles and sent that for analysis also. Credit to Blackstone for saving this engine!
It may well still be the head gasket, but I'm looking for something more definitive before I spend that $ unnecessarily.
What say you, Mazda Gurus??
Blackstone report:
https://www.mazdas247.com/forum/ind...iv-oil-analysis-thread.123854237/post-6716760

*Congratulations, Team Mazda! -- 3rd Place DPi Class (and overall) 2021 24 Hours of Daytona
 
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2020 CX-5 AWD
Well you certainly will want a confirmation of the report, because anyone, Blackstone included, can make a mistake. But if the next report comes back looking the same, then you should do a compression and leak down test, in order to find out what's actually happening with you vehicle's engine and how bad the problem currently is. Then, depending on those test results, you'll need to decide what to do next.
 
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2015 CX-5 GT
Minimal coolant loss, well within the "steam released from water pump" described in the TSB.

Thanks also, Edmaz - I'm still waiting for the results of the confirmation test from Blackstone.
 
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CX5 GT
Bear in mind that even a very small coolant leak can dillute the oil.
Although we havent seen many coolant issues/reports here but also not many people do UOA so..one never knows the stats.
As mentioned in the other thread try a 2nd test at a different company.
 
I have a 2014 CX-5 2.5L SkyActive and just got back a UOA from Blackstone Labs that shows 681 ppm potassium, 267 ppm sodium, and 0.53% antifreeze. I had not had a UOA run in a couple of years, but decided to do so because I recently passed 100,000 miles.

I am also meticulous about maintenance (as I suspect most are who bother to run UOAs), and I've noticed no loss of antifreeze.

Fortunately, the UOA shows no unusual metal wear, so either I caught it early or the test result could be in error.

DaveIndy, what do you mean when you say, " I'm still waiting for the results of the confirmation test from Blackstone." Do they re-run the sample upon request? How does this work?
 
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2020 CX-5 AWD
... I've noticed no loss of antifreeze. ...
Although it was posted previously, I'll also suggest that one or both of you try another lab for your next test. IMO it now appears to be likely that something is not right with what Blackstone is doing.
 
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yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
I have a 2014 CX-5 2.5L SkyActive and just got back a UOA from Blackstone Labs that shows 681 ppm potassium, 267 ppm sodium, and 0.53% antifreeze. I had not had a UOA run in a couple of years, but decided to do so because I recently passed 100,000 miles.

I am also meticulous about maintenance (as I suspect most are who bother to run UOAs), and I've noticed no loss of antifreeze.

Fortunately, the UOA shows no unusual metal wear, so either I caught it early or the test result could be in error.

DaveIndy, what do you mean when you say, " I'm still waiting for the results of the confirmation test from Blackstone." Do they re-run the sample upon request? How does this work?
Sometimes no loss of coolant doesn’t mean your head gasket is fine. It’s a 2-way street, either oil gets into your cooling system, or the coolant gets into your oil, or both. A compression test can tell more stories on your engine.
 
Sometimes no loss of coolant doesn’t mean your head gasket is fine. It’s a 2-way street, either oil gets into your cooling system, or the coolant gets into your oil, or both. A compression test can tell more stories on your engine.
I understand and agree completely. However, I did have a 99 Tahoe that needed two head gasket replacements, and both times I saw the need for makeup antifreeze.

I have been in contact with my mechanic and will definitely go with a compression test before looking to do a gasket replacement. Not cheap!
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
I understand and agree completely. However, I did have a 99 Tahoe that needed two head gasket replacements, and both times I saw the need for makeup antifreeze.

I have been in contact with my mechanic and will definitely go with a compression test before looking to do a gasket replacement. Not cheap!
You may try another OUA from different vender as suggested by others before you decide to do something major to your engine. You should also consider a used engine with less miles from salvage yard if the cost is not much higher.
 
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2015 CX-5 GT
The idea of a "confirmation" test came from other posts. Of course, an error is always possible but not what I was trying to determine. The second test was done at half the previous drain interval because the oil had been changed every 5k miles but the last analysis was done 27k miles ago. The second test is to help me decide between the following 2 choices:
A) Since the engine has 90,000 miles on it, if the leak is small an option is to just keep changing the oil more often. Of course this is not ideal but this car is now a seldom-used 3rd car in our family. With no increase in wear metals or serious viscosity breakdown, choosing not to spend thousands of dollars is an option.
B) If I choose to spend $1500 on a new head gasket, I'm certainly not going to pay what is nearly all labor $ to put belts, tensioner, hoses, etc with 90k on them back on the car. This choice would be a life-extending preventative maintenance investment of approx. $2k.
The second test showed exactly half the amount of K and Na, at half the change interval. For me, this is confirmation that both test are accurate. For the record, I have complete confidence in Blackstone. I know lots of people who rely on them for aircraft and automotive/diesel engine monitoring and have never heard of them producing bad test results, ever. I also switched oils from SpecialTec AA to MolyGen to prove that it was not a problem with the oil. I'll post the Blackstone report on the UOA thread, along with some interesting Qs and As from Blackstone.
For now, the car is going in for a compression test (thanks, Edmaz) and a cooling system pressure check (Blackstone's rec). I'll report those results ASAP.
Thanks for your response, RPF -Good luck to us both!
 
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2020 CX-5 AWD
.... For now, the car is going in for a compression test ...
Given that you described the coolant loss as 'minimal', I recommend asking the shop to do a leak down test along with the compression and pressure tests. IMO it's likely the compression numbers will be fine, and will not indicate an issue. However, the leak down test may possibly provide a different perspective. With all the work already done to remove the plugs, they hopefully won't charge a huge extra amount to do the additional test.

That said, I'm totally mystified that Blackstone describes this as a 'fairly severe coolant leak', when you're not seeing anything close to that when checking the coolant level. 'Fairly severe' to me means adding make up coolant regularly, but perhaps their perspective about coolant in the oil is different than mine. This entire thing is very puzzling to me, and I'm definitely interested to see how the results of all the other testing turns out.
 
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2015 CX-5 GT
Ok, thanks - I'll ask for the Leak-down test too.
I agree..."Fairly Severe" would seem to be at least some visual indication in the oil. However, being oil experts, any amount of coolant in oil is probably alarming to them.
I'll report back next Fri with some more clues.
Thanks to everyone who has responded!
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Ok, thanks - I'll ask for the Leak-down test too.
I agree..."Fairly Severe" would seem to be at least some visual indication in the oil. However, being oil experts, any amount of coolant in oil is probably alarming to them.
I'll report back next Fri with some more clues.
Thanks to everyone who has responded!
So you can’t see any pinkish color in your oil? Can you see any oil floating on top of the coolant when you open the radiator cap with cold engine?
 
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2015 CX-5 GT
Incredibly, No-
No sign of anything unusual in oil, not even a sheen on the top.
I pushed a paper towel into the coolant reservoir, hoping to catch any little bit of slime that might be in there, and wiped the dip tube. Nothing.
When performing the chemical block test, I drew some coolant out with a white rag (as directed to prevent detection fluid from being contaminated with coolant). Coolant came out perfectly blue and clean as new.
 

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