2.5L Oil level fluctuation

Just had my first oil change on a 2016 cx5.

The tech got oil all over the door handle and steering wheel and a little hell raising by me resulted in a no charge oil change. We aren't talking about a single finger print here folks.

So I have no confidence in the work done and my attempts to check oil level have me convinced it is over filled. If it was overfilled, should I get a check engine light code? I hope the answer is yes and I can just ignore what appears to be a high oil level.
How have you attempted to check the oil level and what was the result exactly?
 
Oil and oil filter replacement: 4.5 L {4.8 US qt, 4.0 lmp qt}

Maybe they just put in the entire 5 Quarts. Both the dealer and Juffylube used to do that with my old car and it read a tad high after a change. Shouldn't be an issue
 
Oil and oil filter replacement: 4.5 L {4.8 US qt, 4.0 lmp qt}

Maybe they just put in the entire 5 Quarts. Both the dealer and Juffylube used to do that with my old car and it read a tad high after a change. Shouldn't be an issue
Even if you put in 5 quarts of fresh oil, the oil level only reaches 2/3 ~ 3/4 between Low and Full marks of the dipstick if the old oil been drained properly.

It's been well known that the oil change capacity in owner's manual is inaccurate. Putting in 5 1/8 ~ 5 1/4 quarts will bring the oil level up to the Full mark of the dipstick.
 
Even if you put in 5 quarts of fresh oil, the oil level only reaches 2/3 ~ 3/4 between Low and Full marks of the dipstick if the old oil been drained properly.

It's been well known that the oil change capacity in owner's manual is inaccurate. Putting in 5 1/8 ~ 5 1/4 quarts will bring the oil level up to the Full mark of the dipstick.

Good to know.
 
I suspect the owners manual is based on filling a dry engine which always takes half a quart more.

NC

Edit: I just used a vacuum pump from West Marine and quickly removed what I estimated to be half a quart of oil. The level is now just a hair below the high mark. So the tech probably put in the prescribed amount of oil which is for a dry engine which led to it being half a quart too full. Problem solved and I won't go to that dealer again. I stopped going to the "quickie lube" places to get away from this problem.
 
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I suspect the owners manual is based on filling a dry engine which always takes half a quart more.
NC
Edit: I just used a vacuum pump from West Marine and quickly removed what I estimated to be half a quart of oil. The level is now just a hair below the high mark. So the tech probably put in the prescribed amount of oil which is for a dry engine which led to it being half a quart too full. Problem solved and I won't go to that dealer again. I stopped going to the "quickie lube" places to get away from this problem.
Looks like your dealer overfilled during the oil change which happens quite often. But if your thought is correct, then the owner's manual should state half a quart more than 5 US quarts, not 4.8 US qt. on engine oil capacity. Mazda is keeping the oil level at ⅔ ~ between Low and Full marks on the dipstick from factory fill for our SkyActiv-G 2.5L engine. This is what I found from our special ordered CX-5 when it arrived at our dealer. This is also true after I checked several brand new CX-5's from friends and those form the dealer's showroom. It seems Mazda did it on purpose with the Full mark on dipstick higher than it supposed to be, so that it has some room for fuel dilution issue when the oil level is rising.

I actually bought a bottle of Mazda moly oil and topped it off to the Full mark at first as I thought the oil level was low from factory. But the oil was burned and the oil level was dropped to ⅓ between Low and Full when I did the first oil change at 5,073 miles. I put in 5 quarts of Mazda moly oil like most DIYers and called it a day. The oil level was at about , not at the Full mark. Now at 9,880 miles the oil level is at about between Low and Full marks on the dipstick.
 
Looks like your dealer overfilled during the oil change which happens quite often.

yes it does.
I've had one dealer tell me that the oil is supposed to be filled to the "twist of the dipstick" and another dealer tell me that the "dipstick isn't accurate the techs just fill the right amount."

I finally changed my own oil last time (used the moly oil too) and I gotta say that my car seems to rev much more quietly and smoother.
I'm not sure how much of that observation is placebo, how much is the "magic" moly oil and how much is due to the oil finally being at the right level, but I'm quite happy with the result.
 
I have a 2013 gas Mazda CX5. I live in Brandon Manitoba and as soon as the temperature goes down to about plus 10 Celsius and lower, the engine oil rises up the dipstick (its becomes diluted with gas) I have had the vehicle for 3 winters and the same thing every winter. The dealership does not know what the problem is. My wife drives short distances to work and back. During the winter I check the dipstick daily. I either have to take it on the highway and drive about 100 km to burn of the gas and bring the level down, or change the oil every two weeks. I have lately been only filling the oil to between the add mark and full. Then when it reaches 3/4 of an inch over the full mark, I go for a long drive or change the oil. Its bizarre and frustrating. Gary
 
I have a 2013 gas Mazda CX5. I live in Brandon Manitoba and as soon as the temperature goes down to about plus 10 Celsius and lower, the engine oil rises up the dipstick (its becomes diluted with gas) I have had the vehicle for 3 winters and the same thing every winter. The dealership does not know what the problem is. My wife drives short distances to work and back. During the winter I check the dipstick daily. I either have to take it on the highway and drive about 100 km to burn of the gas and bring the level down, or change the oil every two weeks. I have lately been only filling the oil to between the add mark and full. Then when it reaches 3/4 of an inch over the full mark, I go for a long drive or change the oil. Its bizarre and frustrating. Gary
 
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Hi garycar

Just wait till you get the Skyactiv diesel in the U.S. You will need to check the oil level each week for the oil level rise as a result of unburnt fuel being returned to the engine due to DPF regeneration. As soon as the oil level gets near the "X" mark on the dipstick ( or the oil warning light appears) you have to have a full drain and refill with fresh oil at your own expense or if Mazda is feeling particularly kind on that particular day have it done for free. It's not covered as a warranty requirement. (At least not in the UK).

Jonno21
 
You all do realize that oil will change in volume with temperature.

1/4" on the dipstick is like less then 1/4 of a quart. I think your nuts if you believe that's going to cause engine damage.
Send in an oil analysis and blow your fuel dilution theory away. This isn't a 6.4 Ford here.
Cold starts and short trips will drastically impact fuel dilution.
You should track it and avoid short trips during the timeframe.
It would be interesting to see your fuel trims.
 
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Same oil level problem here !!!

I just started having the same issue with my wife's 2015 CX5 GT. She's racked up just over 64,000 miles since we bought it new in July 2014, so she used to drive ~100 miles/day until just recently when she got a promotion and now works from home and takes just short trips. I'm an automotive engineer and car tuner by trade with over 30 years experience and meticulously maintain my fleet of vehicles way above and beyond the FSM and use the highest quality fluids, parts, etc.

I tried to use my suction pump to extract some of the oil, but unfortunately even the smallest hose (which is the same OD/width as the dip stick) I couldn't get in far enough, so I had to change the oil & filter, even though I had another 3,000 miles to go. Since I didn't have a filter, I went to my local dealer and I have a great relationship with parts and service there and mentioned the fuel dilution problem I am now seeing and mentioned your post. Well, I got the typical "Never seen that before" answer, so I left and did an oil/filter change and only filled it halfway, just before the polar air arrived and temps got down to -15F for a few nights. I just checked the level tonight and it's already up to the full mark after only ~60 miles!

Compression tested good, no head gasket leak, no oil burning (Need some, lol!), the oil looks brand new, just smells like fuel. I'm going in tomorrow and having a serious discussion about this, as this is completely unacceptable.

I feel your pain and will keep you updated. Just glad I found someone with the same problem on the 2.5L petrol engine. Know all about the crap Mazda is playing with the diesel!


I have a 2013 gas Mazda CX5. I live in Brandon Manitoba and as soon as the temperature goes down to about plus 10 Celsius and lower, the engine oil rises up the dipstick (its becomes diluted with gas) I have had the vehicle for 3 winters and the same thing every winter. The dealership does not know what the problem is. My wife drives short distances to work and back. During the winter I check the dipstick daily. I either have to take it on the highway and drive about 100 km to burn of the gas and bring the level down, or change the oil every two weeks. I have lately been only filling the oil to between the add mark and full. Then when it reaches 3/4 of an inch over the full mark, I go for a long drive or change the oil. Its bizarre and frustrating. Gary
 
The volumetric thermal expansion for petrol is about 36% greater than engine oil, so a small amount of fuel will cause a much greater increase in volume vs oil for the same delta-T. Also, this increased level cannot be ignored, as the crankshaft will whip this mixture into an emulsion, that is primarily air and starve and seize the engine, not to mention the bore washing that takes place with that amount of excess fuel.

As far as fuel trims go, which are only applicable once closed loop conditions are reached, STFT's are immediate actions taken by the PCM/ECU to maintain a stoichiometric 14.7 air/fuel ratio and are short term and reset to 0 when the engine is shut off. LTFT's are the history averaged STFT's over a long time period and are stored in the PCM. If the PCM is adding fuel (+%) for a lean condition or removing fuel (-%) for a rich condition and either of these conditions exists for a prolonged period of time and the LTFT percentages exceed the PCM's parameters, a fuel trim code will set (P0170-P0172/Bank 1), since we have a single bank of 4 cylinders, a 170 would indicate a PCM failure to control fuel trims and the 171 & 172 would indicate O2 sensor problems, pre & post cat respectively) and the Check Engine light will be illuminated. That is not the case for either of us. However, I am going to hook up my scan tool tomorrow and check them out. The advent of low tension piston rings and high pressure direct injection serve to exacerbate these problems, especially under low load combustion pressure conditions, which reduce the radial force at the ring/liner interface.

You all do realize that oil will change in volume with temperature.

1/4" on the dipstick is like less then 1/4 of a quart. I think your nuts if you believe that's going to cause engine damage.
Send in an oil analysis and blow your fuel dilution theory away. This isn't a 6.4 Ford here.
Cold starts and short trips will drastically impact fuel dilution.
You should track it and avoid short trips during the timeframe.
It would be interesting to see your fuel trims.
 
I just started having the same issue with my wife's 2015 CX5 GT. She's racked up just over 64,000 miles since we bought it new in July 2014, so she used to drive ~100 miles/day until just recently when she got a promotion and now works from home and takes just short trips. I'm an automotive engineer and car tuner by trade with over 30 years experience and meticulously maintain my fleet of vehicles way above and beyond the FSM and use the highest quality fluids, parts, etc.

I tried to use my suction pump to extract some of the oil, but unfortunately even the smallest hose (which is the same OD/width as the dip stick) I couldn't get in far enough, so I had to change the oil & filter, even though I had another 3,000 miles to go. Since I didn't have a filter, I went to my local dealer and I have a great relationship with parts and service there and mentioned the fuel dilution problem I am now seeing and mentioned your post. Well, I got the typical "Never seen that before" answer, so I left and did an oil/filter change and only filled it halfway, just before the polar air arrived and temps got down to -15F for a few nights. I just checked the level tonight and it's already up to the full mark after only ~60 miles!

Compression tested good, no head gasket leak, no oil burning (Need some, lol!), the oil looks brand new, just smells like fuel. I'm going in tomorrow and having a serious discussion about this, as this is completely unacceptable.

I feel your pain and will keep you updated. Just glad I found someone with the same problem on the 2.5L petrol engine. Know all about the crap Mazda is playing with the diesel!

Before you get all worked up over it, I strongly suggest you send a sample to Blackstone so that you actually know what you're talking about and can prove it with numbers. I am not saying you're wrong, I'm saying more data is better.
 
Don't tell me I don't know what I'm talking about. I worked and designed oil reclamation equipment to extract and fractionate waste oil back into virgin base oils using wfe's, high pressure SCO2 and other technologies. We had a lab 10x more sophisticated than Blackstone as we had to certify color #, TAN, flash point, pour point, viscosity index, ash, etc, and sold group 1, 2, 3 and 4 base stocks back to the blenders. I've processed and tested more waste oil in 1 hour than you will in your lifetime.

Before you get all worked up over it, I strongly suggest you send a sample to Blackstone so that you actually know what you're talking about and can prove it with numbers. I am not saying you're wrong, I'm saying more data is better.
 
I just started having the same issue with my wife's 2015 CX5 GT. She's racked up just over 64,000 miles since we bought it new in July 2014, so she used to drive ~100 miles/day until just recently when she got a promotion and now works from home and takes just short trips. I'm an automotive engineer and car tuner by trade with over 30 years experience and meticulously maintain my fleet of vehicles way above and beyond the FSM and use the highest quality fluids, parts, etc.

I tried to use my suction pump to extract some of the oil, but unfortunately even the smallest hose (which is the same OD/width as the dip stick) I couldn't get in far enough, so I had to change the oil & filter, even though I had another 3,000 miles to go. Since I didn't have a filter, I went to my local dealer and I have a great relationship with parts and service there and mentioned the fuel dilution problem I am now seeing and mentioned your post. Well, I got the typical "Never seen that before" answer, so I left and did an oil/filter change and only filled it halfway, just before the polar air arrived and temps got down to -15F for a few nights. I just checked the level tonight and it's already up to the full mark after only ~60 miles!

Compression tested good, no head gasket leak, no oil burning (Need some, lol!), the oil looks brand new, just smells like fuel. I'm going in tomorrow and having a serious discussion about this, as this is completely unacceptable.

I feel your pain and will keep you updated. Just glad I found someone with the same problem on the 2.5L petrol engine. Know all about the crap Mazda is playing with the diesel!

This TSB only applies to the 2.0L, but it's probably a good reference for you:
http://am.mazdaserviceinfo.com/mazd...&id=TSB4931&contentType=tsb&actionPrint=print
 
So, basically, without this update, your oil will fill with fuel when you drive short trips in cold weather...nice.
 
Oil level update #1

So I confirmed that our 2015 CX5 has been over fueling since day one.
How do I know this?
Well, since day one when we bought it, my wife was driving 80-100 miles/day until just recently, which put almost 65,000 miles on it to date, with no oil level problems.
Over the past month, I encountered a rising oil level, since now she works from home when not traveling and we now only take short trips.
I did an oil/filter change when the level got to about 1/4" above the full mark and smelled totally like fuel. I added just 5 quarts, which puts the level pretty much smack in the middle of the low and full marks.
We drove it around for ~2 weeks on short city, low speed driving and the level slowly crept to ~1/4" above the full mark.
I took garycar's advice and we took a 90 mile freeway drive yesterday averaging 70-75 mph, which is how it had been driven since new.
Before going to the Mazda dealer and talking with my tech, I checked the level and it was about an 1/8" below the full mark, so we burnt off most of the fuel.
My tech found updates for both the PCM & TCM and flashed them and took it for a short drive to calibrate the misfire counter.
There were no pending or active codes and 0 misfires since the last PCM flash about 40,000 miles ago. The fuel trims looked good and the injector pulse width across all the injectors looked good also.
After these updates, we went for a short freeway and city drive and the car feels and sounds much quieter and lights off quicker without the slight hesitation it has always had, even after I changed the plugs at 60k.
Unfortunately, Mazda doesn't list what these updates addressed, but I'm hoping this does the trick.
We bounced around a few ideas like bad injectors or hp fuel pump, but when we were data logging, everything checked out ok.
Got to give a shout out to my local service manager and tech, as even though I know them well, I arrived unannounced and they were jammed, yet they pulled their master tech and immediately worked with me and washed it to boot.
All I can do now is drive and see if it made any difference.
 
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