Mazda Skyactiv PCV System

[DBMaster]

I was searching around for the purpose of learning where the PCV valve is and how to check/change it. It's quite a complicated process for the Skyactiv engines. Here is a detailed look. At least it does appear that the system has a rather large and effective oil separator which SHOULD render a catch can redundant. I wouldn't call this routine maintenance at all.

Skyactiv PCV

 

[NormanBuntz]

The Mazda engineers couldn't design a simpler system than that? Jeez.

 

[2016Accord]

Thanks for posting the link to this doc. I was curious about this as well.

 

[buster]

I'm going to check mine this weekend. Looks like a 1.5 - 3 hour job if it needs to be replaced.

 

[CR94]

Originally Posted by DBMaster
... At least it does appear that the system has a rather large and effective oil separator which SHOULD render a catch can redundant. I wouldn't call this routine maintenance at all. ...
Is it successful keeping deposits from collecting on intake valves?

 

[DBMaster]

Originally Posted by CR94
Originally Posted by DBMaster
... At least it does appear that the system has a rather large and effective oil separator which SHOULD render a catch can redundant. I wouldn't call this routine maintenance at all. ...
Is it successful keeping deposits from collecting on intake valves?

I haven't checked. I'm at 99,000 miles.

 

[littlehulkster]

Originally Posted by NormanBuntz
The Mazda engineers couldn't design a simpler system than that? Jeez.


I'm sure they could, but their worry was probably about the carbon build up that's common in DI engines, and so they went with the more complex design to avoid it.

I'm ok with complexity if it's for the sake of reliability, instead of the complexity for complexity's sake some German manufacturers seem to love.

 

[yugrus]

They essentially have a built-in catch can with integrated PCV valve. It is maintenance-free, as everything sepatated/condensed is draining back to the sump. It appears to be effective, however owners that install secondary aftermarket catch cans report amounts of oil caught. I bet that being integral part of the engine, this contraption has its efficiency limitations because of heat. This is why external catch can catches stuff.
Primary goal here certainly looks like reducing intake valve deposits.

 

[CR94]

Originally Posted by yugrus
... I bet that being integral part of the engine, this contraption has its efficiency limitations because of heat. This is why external catch can catches stuff. ...
Being hotter than an external can would definitely limit its ability to condense water vapor, but why would that be a drawback?

 

[yugrus]

Originally Posted by CR94

Being hotter than an external can would definitely limit its ability to condense water vapor, but why would that be a drawback?

This is not about water at all. The intent of this thing is to condense oil mist and vapor out of crankcase gases.