2014 CX-5 2.5L - Oil analysis shows coolant present

PatrickGSR94

PatrickGSR94

:
2014 CX-5 Touring
Well this is not what I wanted to see. 137K miles on our CX5 Touring that we've owned since 2016 with about 54k miles. Last oil analysis report last July showed a trace of coolant present in the oil, and this oil change end of last month showed more coolant. I have noticed a *very small* loss of coolant over recent months, not a huge amount. The coolant itself still looks clean, and the oil looks clean. I did see a small amount of oily residue on the joint between the water pipe and water pump, up above the oil filter, but haven't seen any signs of anything dripping onto the ground or onto the lower engine cover.

I've read the other posts on here about 2014's with blown head gaskets. On those cars the engine apparently overheated at some point. I haven't had any overheating issues, or any engine codes of any kind. Is there any other way for coolant to mix with oil besides a blown head gasket, or worse, a cracked head? Surely the head wouldn't be cracked if the engine hasn't overheated.

I still need to check compression and test the coolant for any combustion gasses, but if there's no breach between the coolant and cylinders, I don't think those tests will show anything. We can't really afford another vehicle, but I'm highly experienced in doing major engine work (head-off work, head gaskets, engine out work, etc), so I'll just have to try to fix it, assuming it's a head gasket or maybe oil cooler issue.

We're scheduled to head out on our family vacation beach trip in just 2 weeks. There's no way I can work on the car before then. Hopefully we won't have any issues. Sure wish the car had a darn coolant temp gauge....
 
Not sure but there's some software that plugs into the diagnostic port that might read coolant temp.
There's others on the forum that have a multitude of gauges that will read just about every engine parameter. I think Mister Hyflier has some gauge software that shows tons of parameters.
Search the forum.
 
I am sure. I use the BlueDriver plug in scan tool - among many other functions it reads live coolant temperature. I love mine.

us.bluedriver.com

BlueDriver

BlueDriver is the easiest way to scan and understand your vehicle, all from your driveway.
us.bluedriver.com us.bluedriver.com
 
Yeah I have OBD Fusion for my Miata that doesn’t have a functional coolant temp gauge. Since it’s also Mazda I might see if the Bluetooth OBD2 dongle I have in that car will work in this one, since I already have Mazda vehicles downloaded for it.
 
It should work.
I monitor with Forscan (made for ford and mazdas) and a cheap bluetooth obdii adapter bafx. If only coolant temp is of interest, you can download the free version from the forscan site which can show 1 parameter live view for free. You can select which one and change it any time but only 1 at a time shows in the app dash.
If you buy the paid version 7-8$ you can view all at once. But even the free is quite useful.
 
PatrickGSR94 said:
Well this is not what I wanted to see. 137K miles on our CX5 Touring that we've owned since 2016 with about 54k miles. Last oil analysis report last July showed a trace of coolant present in the oil, and this oil change end of last month showed more coolant. I have noticed a *very small* loss of coolant over recent months, not a huge amount. The coolant itself still looks clean, and the oil looks clean. I did see a small amount of oily residue on the joint between the water pipe and water pump, up above the oil filter, but haven't seen any signs of anything dripping onto the ground or onto the lower engine cover.

I've read the other posts on here about 2014's with blown head gaskets. On those cars the engine apparently overheated at some point. I haven't had any overheating issues, or any engine codes of any kind. Is there any other way for coolant to mix with oil besides a blown head gasket, or worse, a cracked head? Surely the head wouldn't be cracked if the engine hasn't overheated.

I still need to check compression and test the coolant for any combustion gasses, but if there's no breach between the coolant and cylinders, I don't think those tests will show anything. We can't really afford another vehicle, but I'm highly experienced in doing major engine work (head-off work, head gaskets, engine out work, etc), so I'll just have to try to fix it, assuming it's a head gasket or maybe oil cooler issue.

We're scheduled to head out on our family vacation beach trip in just 2 weeks. There's no way I can work on the car before then. Hopefully we won't have any issues. Sure wish the car had a darn coolant temp gauge....
Click to expand...
The coolant leak is rare for the 2.5L NA (without cylinder deactivation) on your 2014 CX-5 Touring. It’s too bad that after you’ve spent plenty of time for extensive maintenance on your CX-5 then found you have got such problem. Not sure what would I do if I’m under the same situation. With your DIY skill you can check compression and test the coolant for any combustion gasses. You can then remove the cylinder head and verify the head gasket condition. No matter it definitely is a big hassle for you.

You can use FORscan to display all kind of vehicle’s data in the nice analog gauge format like HyFlyer suggested here:

Torque app - oil dilution quantity
 
yrwei52 said:
This video should help you to remove the cylinder head:



The damaged engine on cylinder #3 and #4 was having the similar problem, coolant mixed with oil, although it’s a newer 2.5L NA with CD.
Click to expand...
Good video. The construction quality of the engine is impressive.
 
Jmaz said:
Good video. The construction quality of the engine is impressive.
Click to expand...
But one loose bolt at the corner of the cylinder head makes me feel otherwise on workmanship.
 
yrwei52 said:
This video should help you to remove the cylinder head:



The damaged engine on cylinder #3 and #4 was having the similar problem, coolant mixed with oil, although it’s a newer 2.5L NA with CD.
Click to expand...

wow awesome, thanks. I looked all over for 2.5L Skyactiv videos and couldn't find much. Gonna be quite a different animal with the engine in the car, though.
 
DaveIndy said:
Here is a thread about my CX5 2.5 SkyActive with a similar issue. I'm not trying to sway your decision, only offering results I have seen with the decisions I have made:
https://mazdas247.com/forum/t/2015-cx-5-2-5-skyactiv-coolant-in-oil.123874610/
My latest UOA was received at Blackstone a few days ago; current turnaround time seems to be about 1 week. I'll post the results asap.
I'd love to hear updates on your engine.
Click to expand...
Thanks, I'll read through your thread also.

So over the weekend I did a few more visual checks. Although the coolant level in the overflow bottle was slightly low, right at the Low line, it was still within the low/full range. I've only added coolant to the bottle once since last July. This time I added another ~8 ounces of FL22 coolant to bring the level up closer to the Full line.

Also, the coolant itself in the bottle and in the radiator look 100% normal. The oil on the dipstick (still showing full after the oil change on 28 April) looks 100% normal. No signs of any frothy or milky residue. Nothing on the underside of the oil cap.

I also hooked up my OBD2 bluetooth dongle that I normally use in my Miata, with my OBDFusion app to monitor coolant temps, while I drove around probably 40-50 miles of both highway and city driving yesterday. AC going the whole time. Temps were SUPER stable at 190-192F the ENTIRE time. Temps were even more stable (and lower) than in my Miata with an aftermarket Koyorad dual-row aluminum radiator. Ambient temp in the 90's outside.

I started to do a compression test yesterday, but realized my compression tester had the wrong size threads on the end. But then later I remembered my leakdown tester has some adapters so I'll try those later. I also purchased a coolant combustion leak tester and fluid that I intend to use this week.

So as of right now, there are ZERO indications of any issues whatsoever, other than the Blackstone lab report. And as of right now, we are planning to drive the car on vacation next week. But I'll have that OBDFusion app running on my phone with the coolant temperature gauge showing, for the entire drive.
 
Sounds a lot like the issue I had (or am having?) with my 2.5T. Two UoAs reported potential coolant leak, but the dealer did a thorough inspection and a compression test and there were no issues. I keep one of the displays on the instrument panel on the coolant temp, and like you, temps have remained steady as a rock.

🤷‍♂️
 
PatrickGSR94 said:
... as of right now, we are planning to drive the car on vacation next week. But I'll have that OBDFusion app running on my phone with the coolant temperature gauge showing, for the entire drive. ..
Click to expand...
Sounds like a good plan. Nice work on checking things out.

With your UOA from Blackstone Labs showing "antifreeze contamination of .11%", doing the math (5qts of oil is 160 ounces X .0011 [.11%] ) comes out to .176 ounces of antifreeze in your oil. Less than 1/4 ounce of antifreeze introduced into the oil over thousands of miles and several months seems like it would be near impossible to detect the source of. That's such a small amount.

I think your response is appropriate... Investigate, monitor and carry on.
 
HyFlyer said:
Sounds like a good plan. Nice work on checking things out.

With your UOA from Blackstone Labs showing "antifreeze contamination of .11%", doing the math (5qts of oil is 160 ounces X .0011 [.11%] ) comes out to .176 ounces of antifreeze in your oil. Less than 1/4 ounce of antifreeze introduced into the oil over thousands of miles and several months seems like it would be near impossible to detect the source of. That's such a small amount.

I think your response is appropriate... Investigate, monitor and carry on.
Click to expand...
I like your analysis, but I assume the .11% is of the oil mass and is remaining material that was introduced as antifreeze. In other words, .11% of the oil is not oil and came from antifreeze.

I'd expect that would be the non-volatile components of antifreeze that remain after the water evaporates out. The antifreeze is mostly water. So presumably to get to the volume of antifreeze missing you'd have to reconstitute that amount of non-volatile remnant.
 
Good point @murky , I didn't think of it that way. Even so, now we're talking about less than 1/2 ounce of antifreeze instead of less than 1/4 ounce?
 
alrighty so I did the combustion gas coolant test and compression test. All showed perfectly normal. Zero combustion gasses present in the coolant, and compression showing 155-155-150-155 so that's perfect. But as I suspect, if it's only coolant getting into the oil itself, the combustion chambers could still be sealed up like normal.

So I guess the next step is to just drive the car on our trip next week, monitoring coolant temps, with my jug of FL22 and couple bottles of oil in the back; and assuming no issues, drain the oil after 2K-3K miles and send it to a different lab, not Blackstone, just to verify the numbers. Anything else?
 
Made it to FL yesterday with zero issues. Coolant temp on my phone stayed rock solid 187-189 in the morning and 190-192 in the afternoon. Checked today and saw no visible coolant loss. Oil still looks good also.

And managed to drop the rad cap down the engine bay, and luckily I was able to open the little access panel in the undertray and retrieve it. Only a minor annoyance.
 
back from the trip on Saturday, zero issues whatsoever. No loss of coolant at all that I can see. Oil level is down just a bit, currently 1/2 quart low after 2,500 miles since last oil change. But in my mind, using 1 quart in 5K miles isn't that bad.

Plan to drain oil within the next ~500 miles or so and get it checked out.
 
So I procrastinated a bit, ended up going about 4,500 miles on that last oil fill. I changed it Saturday with my last stock of Mazda 0w-20 (plan to switch to Mobil1 5w-30 next), and also ordered an Amsoil oil test kit to send my used oil sample for analysis.
 
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