Oil Catch Can for 2017~2018 CX-5?

Mendel Leisk

Member
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2018 Mazda CX-5 GS FWD
I see there's already an "oil separator", as the car comes from the factory, shows in pictures here:

http://www.mcx5.org/positive_crankcase_ventilation_pcv_valve_removal_installation-1410.html

Has anyone added an Oil Catch Can, spliced into the hose between PCV valve and intake manifold? How much did it catch? I'm a little concerned with direct injectors, that they don't get "washed" by gasoline.

I've installed Moroso 85474 on another vehicle, but they are pricey.
 
My MX5 has a similar setup with an "oil separator" that looks like the one in the linked image. I designed a few variations of aluminum and glass catch cans, but most buyers use them with V8 engines that produce the most airborne oil droplets in crankcase ventilation systems. I will see if there is a good spot in which to mount the CC so that it is lower than the valve cover and away from the engine.
By the way, Mazda dealership techs are required to inspect various area for excessive oil buildup, when customers have their Skyactive engine-equipped vehicles in for service or even software updates.
 
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Thank you.

My past experience has been with a 2010 Prius. Looking down through the throttle body, there was always a little "lake" below. I finally cleaned it all out, and the EGR circuit, and installed the Moroso can last fall. In 4000 kms over winter, it collected about 100 cc's, looked to be about 50% oil, and the rest maybe a mix of water/sludge/gas. The Moroso has a tap and spigot on the bottom, so you can mount it low, keep everything looking stock, and drain at oil changes.

It's the direct-injection on the CX-5 that has me especially concerned, no gas washing the valves.
 
Did your Prius have an OEM oil separator, as does our vehicles? If not, the oil pooling could have accumulated faster than it would in our engines. Based upon what I have seen, very few auto gasoline engines have anything similar to what we have. Typically, the valve cover(s) would have internal geometry that is designed to trap some of the oil before it is pulled out, but this "trap" only reduces the oil accumulation downstream slightly.
I designed my catch can filtration so that its primary media is made of larger diameter 316 stainless steel wire. The secondary filter media is made of much finer non-metallic strand that is supported by a stainless steel wire skeleton of sorts. You can see my white paper on air/oil separation here:
http://www.conceptualpolymer.com/Documents/pcvor.pdf
 
Thanks for the info.

My Prius (2010, first year of 3rd gen) did have a rudimentary oil separator: a bolted-on plate area on the crankcase side wall, maybe 5~6 inch square, with a gasket. The PCV valve screwed into that. I didn't remove that plate on ours (the gasket is very tenacious), but I've seen pics with the plate off, and there's a simple labyrinth behind, it looks like the object is to slow the air (with oil vapour) down, have it condense and drip back into the crankcase. Still, not that effective.

I wish it was easier to post pictures here, say just cut-and-paste in the message while posting.

At the end of the day, I think if we just monitor the intake manifold of the CX-5 for the first little while, we'll get some idea. As long as there's a low point where oil vapour might condense and accumulate.

I can get the Moroso 84574 locally in a few hours for $220. Frustrating when I bought one for our Prius through Amazon last fall for $197. These are Canadian prices btw. US mail order I could get for around $145, but when you factor in shipping, duty, and the conversion rate, it works out the same lol.
 
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That is quite a bit of oil and carbon buildup. I have read that Audi 2.0 turbo engines with direct injection require a walnut media-blasting of the intake at 60,000 miles.
My MX5 does not have direct injection, so Chevron Techron and Shell premium gasoline with nitrogen is probably helping. However, My 3 may be accumulating oil where I don't want it.
Thanks for the link to that video.
 
Just an update, after talking to a local Mazda dealership service rep (the Service Manager I think):

1. They haven't been seeing serious intake valve carbon build-up on the CX-5, but they have seen some, enough to warrant cleaning.

2. He's heard of Oil Catch Can use, but mostly on turbocharged.

3. Just off top of his head: Mazda is "maybe" open-minded about OCC and warranty, would not just disallow any-and-all issues due to an OCC. But if there was a direct correlation, if a botched install evidently caused a problem, then then they would fight it.

Something like that. This was just on the phone, I maybe should asked for an email follow up, but I appreciated his candor, and didn't want to push it.
 
So is carbon buildup on the intake valves a thing? I was under the impression that the oil seperator does a good enough job of keeping the buildup in check.
 
So is carbon buildup on the intake valves a thing? I was under the impression that the oil seperator does a good enough job of keeping the buildup in check.

Definitely still an issue with all direct injection engines. The factory oil separator does a good job, but it really just prolongs the time between needing to get the valves cleaned. An oil catch can would simply prolong this time even further, as the oil/fuel/water (blow-by) would need to make its way through the oil separator, then the oil catch can, before being reintroduced into the intake manifold.

If I can skip the time and cost of at least one cleaning, the $50 I paid for my oil catch can is well worth it. Just need to remember to check/empty it every now and then.
 
Definitely still an issue with all direct injection engines. The factory oil separator does a good job, but it really just prolongs the time between needing to get the valves cleaned. An oil catch can would simply prolong this time even further, as the oil/fuel/water (blow-by) would need to make its way through the oil separator, then the oil catch can, before being reintroduced into the intake manifold.

If I can skip the time and cost of at least one cleaning, the $50 I paid for my oil catch can is well worth it. Just need to remember to check/empty it every now and then.
How often would you say the intake valves should be cleaned? I'm at 110,000KM and the car seems to be running well. A rough idle/ rough acceleration is a sign that the valves need to be walnut blasted and I think my idle is getting a little rougher, so I think I will be cleaning the valves soon
 
How often would you say the intake valves should be cleaned? I'm at 110,000KM and the car seems to be running well. A rough idle/ rough acceleration is a sign that the valves need to be walnut blasted and I think my idle is getting a little rougher, so I think I will be cleaning the valves soon

I'm unsure of how often the valves should be cleaned. I think it will vary between engines, but a shop should be able to use a scope to get a look at the valves. I'd just ask a shop to take a look if possible, otherwise I would wait until I know I have the symptoms before getting them cleaned.
 
I'm unsure of how often the valves should be cleaned. I think it will vary between engines, but a shop should be able to use a scope to get a look at the valves. I'd just ask a shop to take a look if possible, otherwise I would wait until I know I have the symptoms before getting them cleaned.

I find it very strange that is varies so much between engine to engine. There was one case on this forum where some guy drove 25,000KM and the inside of his valves looked like the engine has done 4x that amount. very unsettling to see. Over at the BMW forums, the 2007-2010 "N54" version of the 35i turbo engine would consistently get dirty by 60K miles and really need a clean by around 100K. I find it alarming that is it so much less consistent with Mazda's motor. Once you notice a rough idle and acceleration, with noticeably reduced power and efficiency from when new, that is a major sign that the valves require cleaning. I don't recall where exactly I read this, but Mazda studied why DI motors suffer from carbon build-up and determined that when the combustion chamber falls below a certain temperature (<400F?) carbon buildup starts to form. So, this means two things: 1. Short distance driving, not allowing the engine to fully come up to temp is very bad (for other reasons too) and 2. The italian tune-up, when done regularly DOES in fact work, because this increases the internal engine temperatures which will bring it into the threshold where carbon buildup does not form (<400F)
 
I find it very strange that is varies so much between engine to engine. There was one case on this forum where some guy drove 25,000KM and the inside of his valves looked like the engine has done 4x that amount. very unsettling to see. Over at the BMW forums, the 2007-2010 "N54" version of the 35i turbo engine would consistently get dirty by 60K miles and really need a clean by around 100K. I find it alarming that is it so much less consistent with Mazda's motor. Once you notice a rough idle and acceleration, with noticeably reduced power and efficiency from when new, that is a major sign that the valves require cleaning. I don't recall where exactly I read this, but Mazda studied why DI motors suffer from carbon build-up and determined that when the combustion chamber falls below a certain temperature (<400F?) carbon buildup starts to form. So, this means two things: 1. Short distance driving, not allowing the engine to fully come up to temp is very bad (for other reasons too) and 2. The italian tune-up, when done regularly DOES in fact work, because this increases the internal engine temperatures which will bring it into the threshold where carbon buildup does not form (<400F)

People have different driving habits and also live in varying climates. Also, engines have different manufacturers, which means they likely have different factory specs and differing levels of tolerances (i.e. GM likely has different engineering tolerances compared to Honda). The CX-5 with 25k is only one outlier.

What is the "Italian tune-up"?
 
People have different driving habits and also live in varying climates. Also, engines have different manufacturers, which means they likely have different factory specs and differing levels of tolerances (i.e. GM likely has different engineering tolerances compared to Honda). The CX-5 with 25k is only one outlier.

What is the "Italian tune-up"?

An occasional spirited drive where you bring the engine all the way up to redline 1-3 times within a short period of time. If you haven't done so in a while, you will notice a very strong smell from your exhaust, (which is good)
 
I'd be interested to know if Mazda would be open to an aftermarket oil can installation not affecting the warranty. I've been reading about oil cans because I'm looking at new cars and they all have direct inject engines, and I read where a guy had an issue with either Ford or Chevy refusing a major engine repair under warranty (complete loss of oil pressure) at 20,000 miles because the guy installed an oil can. Of course, who knows what all the facts really are...

Regarding valve cleaning, I've seen multiple step maintenance-cleaning products (generally at 20,000 mile intervals) as a preventative. http://penray.com/products/2601-direct-injection-cleaning-kit/ This is injected through the throttle body to clean the back of the valves, in combination with gas tank additive. My brother is a mechanic and told me about them. I've read no reviews of them.
 
What is the "Italian tune-up"?

Synonymous with expensive Italian super/sports cars (when carbs were in) that weren't driven very often and when they were, they were babied. The owners would then take them in for service because the owners complained about something something with way the engine ran.

Well, the mechanics usually determined the car was never appropriately given the beans and they would proceed to do just that. Just as Humid Hummus said, the car's engine, after reaching operating temps was flogged to redline as the engine designers intended them to be used. Doing this on a "quick" 20-30 minute drive usually cleared up any foul running engine as things were "burned" away under the aggressive engine rpms. I could be totally wrong on most of this, but multiple pulls to redline to get the juices flowing is considered an Italian tune-up.

Driving like Ms. Daisy = bad.

Driving like the two car valets in Ferris Bueller'd Day off = good, unless the car belongs to your friend's dad who loves his car more than his wife...

Cheers. (drive2)
 
I'd be interested to know if Mazda would be open to an aftermarket oil can installation not affecting the warranty. I've been reading about oil cans because I'm looking at new cars and they all have direct inject engines, and I read where a guy had an issue with either Ford or Chevy refusing a major engine repair under warranty (complete loss of oil pressure) at 20,000 miles because the guy installed an oil can. Of course, who knows what all the facts really are...

Regarding valve cleaning, I've seen multiple step maintenance-cleaning products (generally at 20,000 mile intervals) as a preventative. http://penray.com/products/2601-direct-injection-cleaning-kit/ This is injected through the throttle body to clean the back of the valves, in combination with gas tank additive. My brother is a mechanic and told me about them. I've read no reviews of them.


Curious if dealer would be willing to install catch can before delivery of my 2019 gt turbo? I*m going to call in the morning and inquire as im still awaiting my delivery. Dealer installed if possible would intact warranty. Would this be crazy expensive?
 
This would be a hard "NO". No dealer would take the warranty risk with this type of thing.

x2. You can install an OCC after you take delivery. Basically, if something goes wrong, the manufacturer/dealer has to prove that the cause is due to the OCC or the installation of the OCC. For example, if your engine appears to be leaking oil and can be traced back to a botched OCC installation, the dealer can refuse warranty. But, if you installed it correctly and the leaking oil is caused by a faulty gasket, that would be covered under warranty.

Conversely, you can just uninstall the OCC whenever you take it in for service. I'm not sure about the CX-5, but on the CX-9 I didn't have to replace/modify any hoses, I just added an OCC to the existing circuit. This makes it easy to uninstall (takes maybe 5 mins to return to OEM).
 
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