Do we really NEED an OCC?!

Assemdew

2020 CX-5 GT w Premium PKG
Hi guys,
I have been here for the last couple of months and I have to say this thread really assisted me in buying my car. However, this is my first day as a registered user on the thread and I thought I would just post a concern that I am having to see what you guys have done/ responded to it. I bought my brand new 2020 CX-5 GT last week and I am really enjoying driving the car around and even my wife (which is so picky LOL) liked the Mazda over the RAV4 and the Forester (LOL she said they drove like a truck after driving the CX-5).
Anyway, I am planning to keep this car at least for the upcoming 6-7 years. With that being said, I would like to follow preventative maintenance measures and do whatever it takes to keep the powertrain and critical parts intact. Been reading some articles/ comments about the CD but I think it is something that we will be stuck with it unless you have the Turbo version which I don't and didn't want.
My major concern is the Gasoline direct injection (GDI), which of course nothing new to Skyactive, but I have been looking into some Youtube videos about carbon buildup on the manifold intakes. When you have some decent buildup say around (40K to 80K) miles, there are many different ways to clean that carbon (you name it). But I have also seen too many people try to reduce the effect of the carbon buildup in the first place. Most auto tech guys recommend the oil catch can (OCC) as an attempt to filter the air from oil vapor that will eventually travel through the PCV and stuck into the intake manifolds.
1- What do you guys think overall?
2- Is it something that you would do if you buy a new car, especially with GDI like the CX-5?
3- Are there any trustful brands for the OCC?
4- Most important question, am I breaching my factory warranty if I would install the OCC? P.S.: I have also purchased an extended warranty.

I really do appreciate the efforts and experiments/ pictures posted over this thread. You guys are spreading the knowledge!!
Salute Mazda Community,
 
I've never rebuilt an engine or anything that significant but here's my take on carbon build up, regularly increase the airflow by revving it up blowing some of that junk through before it can accumulate. Use the manual mode and hold higher revs a couple times a week, give it the beans when getting on the highway, etc.
8 years and 189k and haven't opened up the intake. I could be wrong and the valves are caked with build up.
 
:
2018 CX-5 Sport
I don't think it will have critical carbon build up in 6 or 7 years. I am planning on keeping mine 20 years and I didn't put a catch can on it. If you live in the salt belt you might want to spray it underneath with an anti rust chemical like fluid film to try and keep the new car shine underneath as long as possible.
 
:
2017 Mazda CX-5 GT, 2016 Mazda6 iGT, 2014 Mazda3 sGT hatchback
To OP:
I am concerned about this issue of carbon deposit on intake valves also.
However, Mazda has done the following on their Skyactiv engines:
1. Raised intake valve temperature (water-cooling less) to evaporate whatever falls on the intake valves.
2. Our Skyactiv engine has an oil separator built in. Not sure how it compares to OCC, but it does not need periodical draining.
3. Skyactiv requires thin synthetic oil (0w-20). This helps reduce deposit.

Felix Dan (youtuber) has a video showing his '16 CX5 intake valves. You can take a look over there. Keep in mind that he lives in Thailand (I think). The engine oil and fuel are all different there.

Also, even if you see deposit on the valves, that does not mean you will feel any problem. As long as the deposit is not severe enough, it does not hinder the engine performance.

Some people use CRC intake cleaner by spraying into the intake throttle body.
This has three problems.
1. the bad deposit then goes to your CAT. Who knows what it will do to the CAT? Shortening life span? By how much?
2. you might get CEL initially afterwards, which might take a few drives to disappear.
3. It is not really clean afterwards. Just cleaner than what you started with.

I have been trying to find a walnut blasting shop for Mazda engines (need adapters for specific engine models). None is near where I live. A lot of shops only do Audi/BMW/VW/Lexus(early IS). Apparently, the problem is more severe on those models.

Carbon deposit issue is very bad on diesel engine. You literally need to do cleanup at an internal of mileage like 50K km.

Anyway, this is as much as I learned so far on this.
 
:
2017 Mazda CX-5 GT, 2016 Mazda6 iGT, 2014 Mazda3 sGT hatchback
As to the question of "Do we really need an OCC??"
My thought is: Why not if you are up to DIY.
OCC is not expensive, and installation is not that difficult.
You just need to remember to drain the can periodically.

Does it void your warranty on the engine?
Guess not, but I am not sure of that.
Proceed at your own risk, :)
 

Antoine

Administrator
First of all, welcome and thanks for joining up @Assemdew! Once again the awesome Community here has jumped in to answer questions and provide input...You’re in great hands, enjoy the Forums!

Ps...I think you mean “Forum/Forums” when you say “thread”. This is a thread posted in the CX-5 Forum (CX-5 Engine & Transmission Sub-Forum to be more specific). :)
 

sm1ke

Work In Progress..
Moderator
Contributor
:
Canada
:
'18 CX-9 Signature
IMO an OCC is not really required depending on your driving habits. Temp extremes and short drives can lead to more blowby than usual. The car has an oil separator and PCV valve, plus everything that @ceric mentioned. Use engine oil that meets the OEM spec, and press the accelerator a little harder every once in a while to help the engine burn up some of the deposits. I had an 08 IS250 that should have been affected by carbon build-up, but I suspect my driving habits delayed it long enough for me to never have to worry about it.

Regarding warranty, I'm unsure if it voids it or not, but most of the time the OCC can be installed in a way that is easily returned to stock, in case you do need to make a claim. Because of this, I've installed a no-name Aliexpress OCC on my engine just as a redundancy. So far it hasn't caught any blowby on my 2.5 turbo, but others who installed OCCs have reported catching some blowby.

CorkSport sells an OCC. They come with instructions for installation. CorkSport also sells a valve cleaning tool kit, but you'd need to contact them to see if it would work for the 2.5L engine.
 
:
2019 CX-5 GTR
Ill just have to chime in on the "does X void the warranty?" question.

Modifications of any sort from factory specifications / configuration are always a slippery slope. Does your oil catch can void the braking system warranty? No.

Does the oil catch can void / invalidate / cause hassle for engine warranty? perhaps. But depending on how it is installed / configured - it could be easily removed before warranty work. It really is up to the local dealer on how much hassle they will give the customer for modifications. OCC is a low risk modification with an easy reversal process should you be worried your dealer is not "mod friendly".
 

erhayes

Contributor
:
Mazda CX-5 FWD Touring
I reviewed the MAZDA pictorial example and there seems to be a very nice oil/vapor separator mounted on the engine. In addition; MAZDA claims to address the carbon build up by keeping the intake valve above 400 degrees. Ed
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Hi guys,
I have been here for the last couple of months and I have to say this thread really assisted me in buying my car. However, this is my first day as a registered user on the thread and I thought I would just post a concern that I am having to see what you guys have done/ responded to it. I bought my brand new 2020 CX-5 GT last week and I am really enjoying driving the car around and even my wife (which is so picky LOL) liked the Mazda over the RAV4 and the Forester (LOL she said they drove like a truck after driving the CX-5).
Anyway, I am planning to keep this car at least for the upcoming 6-7 years. With that being said, I would like to follow preventative maintenance measures and do whatever it takes to keep the powertrain and critical parts intact. Been reading some articles/ comments about the CD but I think it is something that we will be stuck with it unless you have the Turbo version which I don't and didn't want.
My major concern is the Gasoline direct injection (GDI), which of course nothing new to Skyactive, but I have been looking into some Youtube videos about carbon buildup on the manifold intakes. When you have some decent buildup say around (40K to 80K) miles, there are many different ways to clean that carbon (you name it). But I have also seen too many people try to reduce the effect of the carbon buildup in the first place. Most auto tech guys recommend the oil catch can (OCC) as an attempt to filter the air from oil vapor that will eventually travel through the PCV and stuck into the intake manifolds.
1- What do you guys think overall?
2- Is it something that you would do if you buy a new car, especially with GDI like the CX-5?
3- Are there any trustful brands for the OCC?
4- Most important question, am I breaching my factory warranty if I would install the OCC? P.S.: I have also purchased an extended warranty.

I really do appreciate the efforts and experiments/ pictures posted over this thread. You guys are spreading the knowledge!!
Salute Mazda Community,
Our Chris_Top_Her has been using a catch can for many years. You’d be amazed how much blow-by his catch can caught. No wonder they saw so much deposit on intake valves whoever took the intake manifold out like felixd and Chris_Top_Her.

Video Cleaning Intake valves CX 5 Skyactiv Gasoline engine
 
:
2017 Mazda CX-5 GT, 2016 Mazda6 iGT, 2014 Mazda3 sGT hatchback
Yrwei52,
I see the point. People look at how much junk got caught inside the OCC and immediately think it works. True, but how effective? Does it reduce 1% of deposit or 90%? No scientific data. Someone (I cannot find the source now) did an OCC and checked the deposit again after a few tens of K miles, and he did not see much improvement over w/o OCC. That is the counter arguement.
So, I am saying that it is not a matter of whether OCC works or not. It does, but how effective?
That is the question we should be asking.

If one can do the following test, that would be very helpful.
1. drive 30K, check carbon deposit
2. clean up fully, install OCC. Drive 30K again, check deposit
Compare the pic between #1 and #2.
That should be convincing. To me, at least.
 

Assemdew

2020 CX-5 GT w Premium PKG
My 2014 2.5 CX5 is running like new at 64,000 miles. I've done nothing special to the engine. Why are you concerned about something no one is having issues with? Ed
Thank you for your reply. That's good news, hopefully, your car will last forever. I understand that it might doe not seem like a major concern at least below 100K miles, however, it is something that does concern anyone who has a GDI engine. I am not trying to disturb you guys or something, I am just trying to see what other fellas have done or responded to the issue.
 

Assemdew

2020 CX-5 GT w Premium PKG
I've never rebuilt an engine or anything that significant but here's my take on carbon build up, regularly increase the airflow by revving it up blowing some of that junk through before it can accumulate. Use the manual mode and hold higher revs a couple times a week, give it the beans when getting on the highway, etc.
8 years and 189k and haven't opened up the intake. I could be wrong and the valves are caked with build up.
Thank you for your reply. I gave it some good eves today on the highway. I have also used the manual pedals, roughly reved it up till 4000 rpm then shifted to the next gear. I think like you said it is something good to be done once or so every week. But if the OCC proven to be working with 2.5L Skyactive, I am definitely going to install one. My main concern is the warranty. I don't wanna end up voiding it lol with the car hasn't exceeded 1K yet lol.
 

Assemdew

2020 CX-5 GT w Premium PKG
I don't think it will have critical carbon build up in 6 or 7 years. I am planning on keeping mine 20 years and I didn't put a catch can on it. If you live in the salt belt you might want to spray it underneath with an anti rust chemical like fluid film to try and keep the new car shine underneath as long as possible.
Thank you for your reply. I do live in the rust-belt unfortunately. Do you have any recommendations for DIY for undercoating? I honestly do not want to be ripped every year going to the shop to undercoat the car. Thanks, man!
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Thank you for your reply. That's good news, hopefully, your car will last forever. I understand that it might doe not seem like a major concern at least below 100K miles, however, it is something that does concern anyone who has a GDI engine. I am not trying to disturb you guys or something, I am just trying to see what other fellas have done or responded to the issue.
I’d use Top Tier gas (Shell only to me) and the latest SP / GF-6 oil trying to prevent those blow-by carbon deposits.
 

Assemdew

2020 CX-5 GT w Premium PKG
To OP:
I am concerned about this issue of carbon deposit on intake valves also.
However, Mazda has done the following on their Skyactiv engines:
1. Raised intake valve temperature (water-cooling less) to evaporate whatever falls on the intake valves.
2. Our Skyactiv engine has an oil separator built in. Not sure how it compares to OCC, but it does not need periodical draining.
3. Skyactiv requires thin synthetic oil (0w-20). This helps reduce deposit.

Felix Dan (youtuber) has a video showing his '16 CX5 intake valves. You can take a look over there. Keep in mind that he lives in Thailand (I think). The engine oil and fuel are all different there.

Also, even if you see deposit on the valves, that does not mean you will feel any problem. As long as the deposit is not severe enough, it does not hinder the engine performance.

Some people use CRC intake cleaner by spraying into the intake throttle body.
This has three problems.
1. the bad deposit then goes to your CAT. Who knows what it will do to the CAT? Shortening life span? By how much?
2. you might get CEL initially afterwards, which might take a few drives to disappear.
3. It is not really clean afterwards. Just cleaner than what you started with.

I have been trying to find a walnut blasting shop for Mazda engines (need adapters for specific engine models). None is near where I live. A lot of shops only do Audi/BMW/VW/Lexus(early IS). Apparently, the problem is more severe on those models.

Carbon deposit issue is very bad on diesel engine. You literally need to do cleanup at an internal of mileage like 50K km.

Anyway, this is as much as I learned so far on this.
Thank you for your reply. Felix Dan has scrubbed some good amount of carbon buildup. I understand that he lives in a different country and maybe with different specs for oil/ fuel, but still, it is something to concerned about. I trust the Skyactiv motors, they seemed superior so far and they do have some excellent reviews all over the web. But if there is something that we can prolong the life of the car and enhance its time span, why not? The pre-installed oil separator is doing a nice job but still, some oil mist/ vapor will escape to the intakes! I believe all modern GDI cars have a pre-installed oil separator but unfortunately, it is not enough!
 

Assemdew

2020 CX-5 GT w Premium PKG
As to the question of "Do we really need an OCC??"
My thought is: Why not if you are up to DIY.
OCC is not expensive, and installation is not that difficult.
You just need to remember to drain the can periodically.

Does it void your warranty on the engine?
Guess not, but I am not sure of that.
Proceed at your own risk, :)
Don't forget the models of cars you have mentioned are more popular and sold than Mazda. Again this is a completely different story (market-share, advertisement, company volume, etc.). So it might be a problem in Mazda but it is not well documented due to the lack of vehicles sold compared to the models you have mentioned.
 
Top