2013~2016 Oil catch can

sm1ke

Work In Progress..
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Canada
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'18 CX-9 Signature
Not sure of the 2.0 but the 2.5 already has a catch can. Putting on another one isn't necessary.
It's not a catch can, it's an oil separator installed at the PCV valve. It basically catches engine blow-by and allows oil to drain back into the engine and everything else to go back into the intake manifold. Adding a catch can is like adding an extra filter. For some people it isn't necessary, and for others it can help quite a bit. It all depends on your climate, your commute and your driving habits.
 

Chris_Top_Her

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San Antonio, Texas
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'15 CX-5 Miata AWD
And your oil. 0w's are more likely to blow by in DI engines.
There is a a lot of good content about it on YouTube.
 

Chris_Top_Her

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San Antonio, Texas
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'15 CX-5 Miata AWD
Not sure of the 2.0 but the 2.5 already has a catch can. Putting on another one isn't necessary.
The factory separator dumps it right back into the system.. there is no catch can built in. 2/2.5 use the same components
 
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2018 CX-5 Sport
Well, oil separator to get the oil out. I haven't seen anyone having problems from carbon build up on valves and there are people who have driven over 100K miles. There will be carbon, even non DI engines got carbon build up over time. For those with an after market catch can, I would be curious what is caught and how much caught when driving normal conservative vs driving fast and aggressive.
 
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2018 CX-5 Sport
And your oil. 0w's are more likely to blow by in DI engines.
There is a a lot of good content about it on YouTube.
Take this video with a grain of salt. The narrator is not a mechanic and non of his cars needed a valve cleaning. He says that you might need a valve cleaning every 30K miles and if you don't you will get poor gas mileage, loss of horse power, miss fires and the check engine light will go on and the engine will give high emissions. He is repeating what he has read or heard else where. Mazda's will get some carbon too and I'm not against installing a catch can but for me personally, I'm not going to install one.
 

erhayes

Contributor
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Mazda CX-5 FWD Touring
I agree with the comment by MyFirstMazda: When viewed in the MAZDA schematic, I see an oil separator which preforms as a continuously emptying catch can. A real improvement over the add-on catch cans that need to be disassembled to empty. Ed
 

sm1ke

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Canada
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'18 CX-9 Signature
Well, oil separator to get the oil out. I haven't seen anyone having problems from carbon build up on valves and there are people who have driven over 100K miles. There will be carbon, even non DI engines got carbon build up over time. For those with an after market catch can, I would be curious what is caught and how much caught when driving normal conservative vs driving fast and aggressive.
Like you said, carbon build-up is pretty much an eventual thing all car owners will have to deal with if you keep the cars long enough or drive them a certain way for a long enough time.

The oil separator delays the carbon build-up cleaning by catching most of the blow-by. An aftermarket catch can attempts to catch the blow-by before it makes it to the oil separator. If anything, theoretically an aftermarket catch can will extend the lifecycle of the OEM oil separator just by taking on some of the "load". That in itself is worth the $25-$100 and 20 mins install time to me.

In case there's any confusion, blow-by is produced when the engine is not at operating temps. More blow-by is produced in climates with high humidity. This means that if your commutes are short enough that the engine doesn't reach operating temps, it will not be hot enough to burn off the excess blow-by. This is why aggressive driving helps, it gets the engine to operating temps faster.

Here are pics of the blow-by caught by an aftermarket oil catch can on Silly Wabbit's CX-9. This was 2k miles after the installation.



Chris_Top_Her also has an oil catch can installed on his 2.5 NA and he has mentioned before that he catches "a lot of blow-by".

I agree with the comment by MyFirstMazda: When viewed in the MAZDA schematic, I see an oil separator which preforms as a continuously emptying catch can. A real improvement over the add-on catch cans that need to be disassembled to empty. Ed
The only difference between an oil separator and a catch can is that the catch can needs to be manually emptied. If one "filter" works well, and a second "filter" can be added without any impact to "flow", then the second filter helps much more than it hurts. Thus the aftermarket catch can is an improvement to the existing system.
 

sm1ke

Work In Progress..
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Canada
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'18 CX-9 Signature
Take this video with a grain of salt. The narrator is not a mechanic and non of his cars needed a valve cleaning. He says that you might need a valve cleaning every 30K miles and if you don't you will get poor gas mileage, loss of horse power, miss fires and the check engine light will go on and the engine will give high emissions. He is repeating what he has read or heard else where. Mazda's will get some carbon too and I'm not against installing a catch can but for me personally, I'm not going to install one.
While it's true that you may never need a valve cleaning, I wouldn't rule it out completely. I had a 1991 Honda Accord with over 200k on the engine. I had put half of the mileage on the engine myself, and by all accounts it seemed to be perfectly fine - ran smooth, decent mileage. I did a Seafoam cleaning (essentially a chemical cleaning of the intake valves) before an oil change, as recommended by my uncle (a mechanic, now retired). Immediately I noticed better engine response, and also noticed better mileage. The point in this story is that while a cleaning isn't required, sometimes it can help, even when you aren't seeing any major symptoms. All a catch can does is delay having to do that cleaning even longer. It helps to prolong the efficiency of the engine.
 

ColoradoDriver

Gen-1 Kodo Design
Contributor
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Denver, CO
:
2014 CX-5 Touring
While it's true that you may never need a valve cleaning, I wouldn't rule it out completely. I had a 1991 Honda Accord with over 200k on the engine. I had put half of the mileage on the engine myself, and by all accounts it seemed to be perfectly fine - ran smooth, decent mileage. I did a Seafoam cleaning (essentially a chemical cleaning of the intake valves) before an oil change, as recommended by my uncle (a mechanic, now retired). Immediately I noticed better engine response, and also noticed better mileage. The point in this story is that while a cleaning isn't required, sometimes it can help, even when you aren't seeing any major symptoms. All a catch can does is delay having to do that cleaning even longer. It helps to prolong the efficiency of the engine.
Isn't something like Seafoam not really going to do anything for a DI engine? I had heard that, but wasn't sure.
 
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2014 Mazda3 S GT auto, 2008 MX5 6-speed
I wrote this "white paper" about catch cans, a while back.

http://www.conceptualpolymer.com/Documents/pcvor.pdf

A couple of pointers:
1. Catch cans are typically mounted downstream of the PCV valve, since many PCV valves require some oil to stay functional.
2. Oil is easier to trap if it is more viscous, so the cooler the filter media and catch can, the greater the volume of oil and moisture that will be trapped.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
Well, oil separator to get the oil out. I haven't seen anyone having problems from carbon build up on valves and there are people who have driven over 100K miles. There will be carbon, even non DI engines got carbon build up over time. For those with an after market catch can, I would be curious what is caught and how much caught when driving normal conservative vs driving fast and aggressive.
Wait until you actually take your intake manifold off and see if you have any carbon build up on valves. This video shows very severe carbon build-up on his CX-5 with only 28.9K kms (18K miles):

Hi all , just would like to share a video . If you haven't done intake valve clean up check out this video . There's a lot of carbon build up on our engines.

Vehicle done 28.9xxKms on the clock.

Enjoy

Chris_Top_Her installed oil catch can because he also took intake manifold off and saw the carbon build-up. We shouldn't be questioning his driving style to contribute carbon build-up. Like Chris_Top_Her said, factory separator dumps the blown-by right back into the system, because there's nowhere to go.
 

NelsonLewis

Banned
:
16.5 CX-5 GT AWD w/Tech BRMica
We shouldn't be questioning his driving style to contribute carbon build-up. Like Chris_Top_Her said, factory separator dumps the blown-by right back into the system, because there's nowhere to go.
I question his driving style, it's one of the main reasons to have it...Necessary, certainly not, but I can't blame someone for installing one with how simple and cheap one is...
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
Like you said, carbon build-up is pretty much an eventual thing all car owners will have to deal with if you keep the cars long enough or drive them a certain way for a long enough time.

The oil separator delays the carbon build-up cleaning by catching most of the blow-by. An aftermarket catch can attempts to catch the blow-by before it makes it to the oil separator. If anything, theoretically an aftermarket catch can will extend the lifecycle of the OEM oil separator just by taking on some of the "load". That in itself is worth the $25-$100 and 20 mins install time to me.

In case there's any confusion, blow-by is produced when the engine is not at operating temps. More blow-by is produced in climates with high humidity. This means that if your commutes are short enough that the engine doesn't reach operating temps, it will not be hot enough to burn off the excess blow-by. This is why aggressive driving helps, it gets the engine to operating temps faster.

Here are pics of the blow-by caught by an aftermarket oil catch can on Silly Wabbit's CX-9. This was 2k miles after the installation.



Chris_Top_Her also has an oil catch can installed on his 2.5 NA and he has mentioned before that he catches "a lot of blow-by".



The only difference between an oil separator and a catch can is that the catch can needs to be manually emptied. If one "filter" works well, and a second "filter" can be added without any impact to "flow", then the second filter helps much more than it hurts. Thus the aftermarket catch can is an improvement to the existing system.
Well said!

Chris_Top_Her had shown us a picture before on how much blow-by his catch can gathered which has similar amount, if not more, from Silly Wabbit's CX-9. Unfortunately he seems to have lost his picture after the forum system update.
 
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