Discussions

I have a 2013 Mazda CX5 with the new SkyActive Technology and during the cold winter months my engine oil becomes diluted with gas during 20 km a day drives. I can actually watch it rise daily on the dipstick. I either have to drive 300 km to bring it down to full or change the oil. During the summer months its not a problem. I have contacted many Mazda dealerships over this. I was wondering if anyone else has had the same problem with the SkyActive Technology. PM me if you like.

Before we bought ours. I can not seem to find the link, but I will keep looking, and if I find it, I will message you. I seem to remember the problem being that someone put in a wrong oil filter or oil type. I would also look into the recall bulletins. Ours recently went in for a recall notice to reprogram an efficiency problem that signals a misfire at certain speeds and operating temps. Overall, we love the car. VERY good mileage. My wife's original 1989 Mazda had the original clutch and no engine problems when we retired it at over 300,000 kms a few years ago when we bought the new car. Mazda makes great cars.

You need to drill 2 small holes in the exhaust about the size of a pen tip (the big rectangle part one on each corner at the front of it) at the back of the car to let the water drain out do a oil change if you have thi  
s problem again it will most likely need a software update also

Diesel engine by chance? There is a mention of it online if you google "mazda skyactive rising oil problems", and it pertains to the diesel engine having issues with the exhaust cycle adding to the oil level.

What's happening in the winter months it's not getting hot enough to burn off the moisture and it's getting caught in the exhaust and possibly freezing so instead of your engine exhausting it is getting trapped going back into your engine

thats normal with direct injection gas engines, they are not designed for cold weather. they inject fuel against the cylinder walls for better atomization of fuel, but in cold climate it condenses and drains into the oil till the engine warms up. all you can do is have the crankcase vent checked and try to reduce the idle time when the engine is cold. this isnt just a mazda problem it effects all direct injection to different degrees.

amber&jeremy said "thats normal with direct injection gas engines, they are not designed for cold weather. they inject fuel against the cylinder walls for better atomization of fuel, but in cold climate it condenses and drains into the oil till the engine warms up. all you can do is have the crankcase vent checked and try to reduce the idle time when the engine is cold. this isnt just a mazda problem it effects all direct injection to different degrees. "

a Direct injection engine and never have had a problem with oil or anything for that matter. I installed a oil catch can to keep the intake valves clean. which is the only thing I know is a problem with gdi engines. But I don't have a Mazda and from the sound of things I never will. Not well made.

You have problems with the fuel injection system. It is injecting too much fuel at cold temps. This unburnt fuel is ending up in your crankcase. This dilutes the oil dramatically and will harm the engine which will lead to premature engine failure. Get it repaired asap!!

I really do appreciate the response, and advice given. My 2013 Mazda CX5 is a gas engine. I have had the recall done, and have tried the above and so many other different things in an effort to resolve this. What seems to work best during the cold months is to put a cover on the front, keep it plugged in while in my insulated garage, don't let it idle to warm up, and drive it in manual so I can keep the revs up. But my main purpose of this discussion was to see if there are any others experiencing the same issue as me. I can't imagine I am the only one. By the way, I still love the CX5, and am committed to figuring this out. It has 81,000 km on it, and this is the only problem I've had. If I drove an hour to work each day, this would not even be a problem. Such is life.

unatomized fuel is getting past the rings and flowing back in to the oil pan at a rate that you can see daily, (thats a lot) would that not mean also that once the oil is hot and more flowable it would be coming past the oil rings as well and getting burned in the cylinder?  
 
i would be talking to some reputable mechanics,get some diagnostics done and maybe getting a test of the oil to see if it is fuel in the oil.  
 

I can certainly smell fuel on the dipstick,and had the smell confirmed by a mechanic, but the weird thing is that it only does this when the outside temperature is below freezing and when I am driving short distances. I can drive short distances in the summer and its fine. In February I drove to Calgary. When I left Brandon I was over full by 1/2 inch. When I got to Calgary and checked the oil after it sat all night(and on the level)it was down to full. This has played out over and over during the past two years. It gets no worse and it gets no better. I guess the next thing on my list should be to get the drained oil tested, just to be sure. I haven't done that yet.  

I am not a Mazda technician, however I have worked on many GM vehicles with direct fuel injection. Not sure if Mazda employs a similar injection system, but there has been some issues with the high pressure fuel pump leaking fuel into the crankcase in some GM's. Especially during cold temps. We have found that the high pressure fuel pump (which is mechanically actuated from the camshaft-uses a plunger or rod in the engine, coming out from the cam cover or cylinder head-yes, oil side of engine) seal fails and seeps minute amounts of fuel into the oil, causing premature timing chain wear and other issues from the oil dilution.  
Generally speaking, if raw unburnt fuel is leaking past the piston rings, the incomplete combustion will also produce large amounts of black smoke/rich condition. The catalytic converter is good at burning a small amount of unburnt fuel, but would be damaged/overheated by such an amount of fuel that you would notice poor power as the catalyst starts to plug, and a check engine light indicating poor catalyst efficiency.  
This is why I'm willing to bet the mechanical high pressure fuel pump is your issue, nothing else.  
A leaky injector would cause a misfire and a check engine light  
It might be difficult to prove the pump is leaking at these warmer temperatures, but it's worth investigating.  
Good luck.

Many GDI engines actually inject gas during the exhaust stroke on cold start up to allow this fuel to enter the exhaust system. this speeds up the warmup of the catalyst converter to reduce emissions. This results in some fuel washing by the pistons and into the oil during a cold start. If your vehicle is in a garage, this cold start condition is much shorter compared to sitting outside. Multiple cold starts and short trips add up to oil dilution in our climate. I cut my oil change interval in half to account for this in the winter. My vehicle is not a Mazda but has the same condition.