Intake Valve Carbon Buildup on 2017 and Later Skyactiv Engines

[PVQ]

I am wondering if anyone can report whether or not they have experienced carbon buildup on intake valves in 2017 or new GDI Skyactiv engines. I am trying to determine whether or not Mazda engines are susceptible to this issue. Some of what I've read suggests Mazda "solved" this problem, but Ive also seen some youtube video which clearly shows carbon buildup on intake valves of Mazda Skyactiv engines, but mostly earlier models.

Thanks in advance for your answers

 

[dougal]

Not sure what to tell you. I have >100K miles on my 2014 and am getting the same basic performance and gas mileage as before - actually my mileage has been particularly good these last few months.

If there is buildup, it does not appear to be having much negative impact.

 

[Puyapim]

Its likely too soon to really know that question but from what I have gleaned, Mazda SkyActiv engines seem to have a handle on intake deposits.

There are a lot of variables here. If you short trip a lot then the possibilities increase. That is true with any DI engine.

 

[Humid Hummus]

These motors have an EGR valve which acts like an oil catch can to seperate oil from water. There is practically zero carbon buildup on the intake valves, or anywhere else in this engine.

 

[yugrus]

These motors have an EGR valve which acts like an oil catch can to seperate oil from water. There is practically zero carbon buildup on the intake valves, or anywhere else in this engine.

Can you elaborate where the said EGR valve is located? And while you're at that, what oil from which water please?

 

[Humid Hummus]

Can you elaborate where the said EGR valve is located? And while you're at that, what oil from which water please?

My mistake, it's actually part of the PCV valve assembly, shown here in this diagram:

http://www.mcx5.org/positive_crankcase_ventilation_pcv_valve_removal_installation-1410.html

 

[yugrus]

My mistake, it's actually part of the PCV valve assembly, shown here in this diagram:

http://www.mcx5.org/positive_crankcase_ventilation_pcv_valve_removal_installation-1410.html

Ok, but what kind of water does it separate from oil???