Mazda CX5 2.2 blowing through oil cap

My Mazda CX-5 2.2 2014 blows a lot when the engines running and I remove the oil cap, does anyone know the cause and could it be the PCV valve.

If so does anyone know how to get access to it to be removed??

Thanks
 

sm1ke

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What do you mean when you say it "blows a lot"? Do you mean visible exhaust from the tailpipe?

Also why are you removing the oil cap with the engine running?
 
You're correct why would someone remove the oil cap when the engines running, I don't know why I did because I normally turn the engine off before checking The oil.

Anyway it does blow a lot I haven't noticed any water loss or oil consumption, could something be causing it or do you think it's normal??

Cheers
 
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sm1ke

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Assuming you're referring to the exhaust, it could be a number of things, but most of the major problems have clear symptoms. For example, dense, white exhaust smoke that takes a while to clear is evidence of coolant in the engine oil. Exhaust that comes out blue and smells like oil or fuel is evidence of oil/fuel dilution or excessive oil consumption. If the vapours disappear quickly or decrease significantly after startup, it may just be condensation in the exhaust that is evaporating into steam when the hot exhaust gases pass over it.

If ambient temps are starting to drop where you live, this would make the exhaust vapours more visible as well.
 
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2014 mazda cx-5 touring FWD
It appears he is talking about "puffing" out of the oil filler cap when the engine is running. That can be caused by crankcase pressurization due to blowby past the piston rings. He did mention PCV valve and in a diesel (which I'm not familiar with) a plugged PCV valve may allow pressure buildup if the system is designed for aggressive crankcase vapor removal. Also remember that combustion chamber pressure increases ring sealing and at idle the CC pressures are low. I remember seeing diesels slobbering oil out of the mufflers at idle but none when under load. Who is the resident Mazda diesel expert on this board. This is out of my realm of experience.
 
Justyjust, that blowby is normal. If you have variations in antifreeze, *then* you have a problem (with a blown head gasket).

As posted above, combustion forces *some* exhaust past the rings, into the crankcase. At small throttle openings, the rings are not forced against the cylinder walls very tightly (higher combustion pressures actually force the rings harder against the cylinder wall).