Catch Can

S

SmurfaceWarfare

Member
:
2013 CX5 Touring
I am on the newsletter from Corksport, and they sent out an email describing why catch cans are beneficial for direct injection engines. How many are considering running one as extra insurance? To me it is tempting, it's not much $$, and it seems easy enough to install, I just don't see how you empty it. How strict is Mazda about voiding their warranty if one were to be installed? I know the Magnuson Moss act, but it is a huge headache that I really don't want to deal with.
 
SmurfaceWarfare said:
I am on the newsletter from Corksport, and they sent out an email describing why catch cans are beneficial for direct injection engines. How many are considering running one as extra insurance? To me it is tempting, it's not much $$, and it seems easy enough to install, I just don't see how you empty it. How strict is Mazda about voiding their warranty if one were to be installed? I know the Magnuson Moss act, but it is a huge headache that I really don't want to deal with.
Click to expand...

These cans work really well at increasing the wallet thickness of those who pimp them and decreasing the wallet thickness of those who purchase them. The only way it's worth the money is if your thinner wallet helps prevent lower back problems.

If you have ever disassembled a modern engine that was kept in proper running condition for over 100,000 miles you will be amazed at how clean they are. If the CX-5 engine could get higher fuel economy and more power from a simple steel can and a bit of hose then Mazda would have included one (and they probably would have included a petcock drain valve to make it easy to service). It would be foolish of Mazda engineers to leave performance and MPG on the table for want of a small amount of steel and tubing.

This is a solution to a problem that doesn't exist. Spend your time and money on something that will actually improve your life.
 
Anyway... Catch cans are a good idea... It simply catches the oil that gets blown by the PVC valve and eventually ends up in the intake manifold and valves...

It won't help performance, and don't buy anything that is multiple hundreds of dollars...

The cheap/easy thing is to get the inline air compressor filter... They are typically smaller, so you'll have to empty it more frequently, but it's far cheaper, and does the same job... Well worth it.
 
It is possible to make a catch can out of any solid bottle. I would not bother installing a catch can into the CX-5 especially if it is under warranty. Oil accumulation in the CX-5's intake is not an issue as of yet and highly doubtful it will be an issue.
 
SmurfaceWarfare said:
I found this over at a Mazda3 forum. They OP used a scope and looked at his valves at 20k miles or so. I am coming from the VW community which is why I started looking into it. The reviews are mixed so far, some are for and some against.

http://mazda3revolution.com/forums/...ctiv-owners-beware-intake-valve-deposits.html
Click to expand...

I visit this forum as well and I was worried about that post. I removed my exhause to replace it and there are serious deposits after only 10k that will just build up over time (we'll see). I don't have the equipment to look in the motor though.
 
This potential issue has been in the back of my mind since I purchased the car.
My Speed6 is DI, and this is a pretty serious issue with that engine. I didn't read the CS newsletter, but I imagine it may have detailed how carbon deposits on DI engines is quite common on many other makes/models.
Without the benefit of gas additive detergents washing over the intake valves, as is the case with port injection, and with multiple emissions based functions that are still implemented into DI engine designs, like PCV, CCV, and EGR, it is very real probability that carbon will cake over time.
I think a OCC is a good idea on a DI engine overall, on the PCV system. I think simply suggesting the manufacturer's warranty is something to fall back on is a little unrealistic.
And an OCC isn't simply a steel can. Good ones, like CS's, features an internal baffle, which is where the magic happens.

Anyway, it may be something to look into. I'm going to remain pretty hands off myself. Maybe I'll take a peek at around 50K miles or so to see what exactly we are up against.
 
Chris_Top_Her said:
I visit this forum as well and I was worried about that post. I removed my exhause to replace it and there are serious deposits after only 10k that will just build up over time (we'll see). I don't have the equipment to look in the motor though.
Click to expand...

You installed the Corksport Short Ram Air Intake on your CX-5 back in October and reported it dropped your mileage by 4 MPG down to only 20 MPG. You were warned this would not improve the way your engine ran but you did it anyway.

If you have excessive carbon deposits in your exhaust it's because the Corksport Short Ram Air Intake changed the breathing characteristics of your engine, a catch can will do nothing to fix this!

Modern cars in good running condition do not build up excessive carbon in the exhaust.
 
SayNoToPistons said:
It is possible to make a catch can out of any solid bottle. I would not bother installing a catch can into the CX-5 especially if it is under warranty. Oil accumulation in the CX-5's intake is not an issue as of yet and highly doubtful it will be an issue.
Click to expand...

Very sensible advice.

People visiting car forums need to be aware that there is a lot of misinformation being spread by people who want to make a profit from problems that do not exist. Sometimes they even pose as regular forum members.

I do not know of a single new car from Mazda, Honda, Nissan or Toyota that would benefit from a catch can. But of course it's your car and your $170.00.
 
Never expressed interest in the catch can. And I highly doubt the filter is making more soot; just externally there was always a lot of soot accumulation on the exhaust compared to my old vehicle, and the guy who did that stetho doesn't have an aftermarket intake. Really the 20mpg probably has more to do with the speed at which I drive and the area I drive in (as most users report an MPG increase). Again, I can't speak for the motor because I've haven't looked in it, nor would I have a comparison to the stock intake if I did.
 
Chris_Top_Her said:
Never expressed interest in the catch can. And I highly doubt the filter is making more soot; just externally there was always a lot of soot accumulation on the exhaust compared to my old vehicle, and the guy who did that stetho doesn't have an aftermarket intake. Really the 20mpg probably has more to do with the speed at which I drive and the area I drive in (as most users report an MPG increase). Again, I can't speak for the motor because I've haven't looked in it, nor would I have a comparison to the stock intake if I did.
Click to expand...

Last november you posted this:

I bought the Corksport SRI about 2 months ago. First, I would not recommend it. It does makes my car sound like it has a beast engine, and gives that popping when shifting at high rpm's. You waste gas to hear this and it doesn't really seem to be adding anything noticable. It also reduced my mpgs to about 24 max (w/ cruise control), now i average about 20mpg, when before I was at about 24mpg.
Click to expand...

That popping noise you heard when shifting at high rpm's is unburned fuel/air mixture igniting in the hot header. And if you don't think that's going to cause soot and consume more fuel than a car that is not "popping" then I can't help you.
 
Geeze...

Carbon depositing on the intake valves on DI engines is nothing new. It is FACT and isn't indisputable. It isn't just some selling point for catch cans. If you have soot, and oil mist/vapor introduced into the intake tract by the PCV, VCC and EGR, which is FACTUAL, carbon is going to deposit on the intake valves. This isn't arguable.

The question is, has Mazda implemented something into the design of the S-G engine (valve timing?), seeing as it is a problem on their previous DI engines (like the DISI MZR), and a recognized issue in the industry.
I agree a couple hundred bucks is alot to drop before knowing how serious of an issue it is on these engines. That is why I am playing it safe, and not worrying about it until more data becomes available.

I am not surprised either about negative results with the aftermarket intake. The ECU ought the be able to compensate (LTFT/STFT) fueling for the increased airflow/lost restriction. But it certainly is optimized without some sort of tuning solution to remap the ECU.
 
IHeartGroceries said:
The question is, has Mazda implemented something into the design of the S-G engine (valve timing?), seeing as it is a problem on their previous DI engines (like the DISI MZR), and a recognized issue in the industry.
Click to expand...

I will look for the website I found this in, but I heard that Mazda was increasing the temperature in the intake to minimize carbon deposits. It seemed like it was their solution to the common DI issue.
 
IHeartGroceries said:
Geeze...

Carbon depositing on the intake valves on DI engines is nothing new.
Click to expand...

Obviously I was responding to Chris_Top_Her who said he was concerned about the carbon he saw in his exhaust when he removed it. Carbon build up in the exhaust system is from a poor running engine.
 
IHeartGroceries said:
Geeze...

Carbon depositing on the intake valves on DI engines is nothing new. It is FACT and isn't indisputable.
Click to expand...

Actually, carbon forms on the valves of non-direct injection engines also. The amount varies by engine, type of driving, climate, etc. There are already GDI engines that do not have a history of carbon issues (GM V-6 for one). The real question for any type of engine: will the engine go it's full service life without experiencing an issue from carbon deposits. And here I think we largely agree, without good evidence that the SKYACTIV engines have a carbon build-up problem, I'm not worried about it.

The question is, has Mazda implemented something into the design of the S-G engine (valve timing?), seeing as it is a problem on their previous DI engines (like the DISI MZR), and a recognized issue in the industry.
Click to expand...

Yes. All SKYACTIV engines feature variable valve timing (ECU controlled) on both the intake and exhaust valves. This is a big help in controlling valve deposits. Perhaps just as valuable is that all SKYACTIV engines have extra long, scavenging exhaust headers that are designed to prevent combustion exhaust from being drawn into adjacent cylinders. The synergistic effect of both these technologies working in harmony should insure it's not an issue. Note also that some of Mazda's early direct injected (non SKYACTIV) engines did have issues with carbon deposits under some conditions. You can bet that Mazda was aware of the source and composition of these deposits and the conditions under which they formed. You can also bet that if they could reduce these deposits with a more effective breather catch system - they would have. It would likely be built into the crankcase itself - not an external steel can with hoses running all over the engine bay.

The SKYACTIV technologies were released as a move away from older, less effective technologies, it is Mazda's way of saying, yes, we ARE moving forward. I am confident Mazda engineers would not have over-looked a more effective breather catch system if such a system would reduce or eliminate valve deposit issues.

I have complete confidence that carbon valve deposits will never be an issue for my CX-5.
 
Getting very tired of the "Mazda knows best" argument... It's shallow when applied so liberally and doesn't hold up very well...

Manufacturers have issues... They try to minimize any issues, but they don't factor in every possibility...

Getting to this discussion: nearly every car out there would benefit from a catch can... They're inexpensive when diy'd, and effective in helping to keep out as much oil vapor out of the intake as possible... Oil wasn't designed to be fed through the intake and combusted in the chamber... It won't create any more horsepower, but it will help to keep things clean and working well years down the road...

The inline filter I was talking about can look similar to:

22724250052_large.jpg
 
apexanimal said:
Getting very tired of the "Mazda knows best" argument... It's shallow when applied so liberally and doesn't hold up very well...
Click to expand...

I didn't say "Mazda knows best" but they do know more about their engines and the possibility of carbon deposits than your neighborhood "performance" shop. My point was simply that if the engine had a carbon deposit issue that could be fixed with a more efficient oil catch system that would cost practically nothing, don't you think they would have adopted it by now?

And, no, not every engine would benefit from an aftermarket oil catch system. In fact, most cars would show zero benefit. I have a long history of cars that did not have any aftermarket OCS and did not suffer any adverse effects from not having it.
 
I'm with MikeM this time. I think he is completely right about Mazda engineers knowing what is best. They spend millions designing these things and Mazda's overall reputation for reliability (some exceptions) is on the line. I know my first year CX5 has had some minor issues and Mazda so far has taken care of them expeditiously. The carbon deposit issue (for some early DI engines) is a very well know thing now and the loss of power over time is the result. Mazda engineers could not have just looked something like this over. Its been all over the net for years.

Its a fact that synthetic oil is far less prone to carbon/sludge buildup than regular motor oil and I feel that this is just one reason why Mazda engineers recommend it in the direct injected Skyactive engines.

You guys should be careful too when modifying anything to do with the Positive Crankcase System. Its plays a critical roll in keeping the pressure inside the engine on the negative side in relation to atmospheric pressure outside the engine. its not just a pollution control system. Those inline filters (shown above) are designed for high pressure air systems so I would be wary of them; the idea does seem sound at first. I've seen many engines with failed main seals and leaking oil everywhere because the PVC system failed and it doesn't take much to upset the balance especially as an engine ages. Actually I think faulty PVC valves were an issue with the 3-liter sixes in the 2005 Mazda 6 right?
 
Last edited:
The issue of carbon build up on direct injection engines is a BIG issue with Turbocharged engines. Up To this point, I have not seen much of an issue with normally aspirated engines. Unless there was some proven performance benefit of catch cans, I would not worry about carbon build up with our cars.
 
Please log in or register to reply here.

Similar threads

C
Is the stock catch can/system replaceable on a 2017 CX-5?
Replies
15
Views
4K
clownshoes2
C
G
DIY Engine oil change and Manufacturer Warranty
2 3 4
Replies
64
Views
7K
N7turbo
N7turbo
W
2017~2024 Weird feeling accelerating with CX-5 Turbo
Replies
13
Views
2K
1killera4
1killera4

Latest posts

Back