Oil Catch Can. Yes or No?

[Wschnitz]

What 'Cons' are you guys even finding for running one besides having to empty it every oil change?

Oil reduces octane so if anything not having oil mist going into intake is good overall, even if its not really a problem in the first place.

I think I'm eventually going to get a nice one from Radium/Nuke/Mishimoto eventually because of what I've seen the BMW guys deal with on their DI. I'm pretty sure BMW even made a TSB about it saying they recommend walnut blasting the intake at least every 80k miles on cars with DI.

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[RCMUSTANG]

None.

 

[Floyd]

What 'Cons' are you guys even finding for running one besides having to empty it every oil change?

Oil reduces octane so if anything not having oil mist going into intake is good overall, even if its not really a problem in the first place.

I think I'm eventually going to get a nice one from Radium/Nuke/Mishimoto eventually because of what I've seen the BMW guys deal with on their DI. I'm pretty sure BMW even made a TSB about it saying they recommend walnut blasting the intake at least every 80k miles on cars with DI.

A couple of questions..
1] Where can I find information on your claim that oil(in this context) reduces octane? Assuming you mean in the fuel charge at the cylinder?

2] What oil? I expect my oil to show on the exact same place on the stick before and after an oil change.

I would guess that you would see that the "mist" is composed mostly of condensation an blow-by fuel.
I would also expect that both would be minimal, considering the most advanced fuel management in history,combined with the most advanced PCV system ever devised.

I'm not opposed to a catch can or questioning your choices, but if you think there is a need why not choose an Air/Oil Separator, which doesn't require manual draining? Is it just the cost?

 

[DavidR]

What 'Cons' are you guys even finding for running one besides having to empty it every oil change?

Oil reduces octane so if anything not having oil mist going into intake is good overall, even if its not really a problem in the first place.

I think I'm eventually going to get a nice one from Radium/Nuke/Mishimoto eventually because of what I've seen the BMW guys deal with on their DI. I'm pretty sure BMW even made a TSB about it saying they recommend walnut blasting the intake at least every 80k miles on cars with DI.

The cons are pretty small. One of them is that here in CA, you will likely need to remove the can, connect the two hoses together, and tuck the hoses away somewhere out of view when getting smog checks. That seems a pretty small disadvantage if it helps push the walnut shell blasting out well beyond 80K miles.

 

[RCMUSTANG]

Here's what I caught in about 3000 miles. It's pretty much just oil. Not cold enough for condensation in southern California.

 

[DavidR]

Here's what I caught in about 3000 miles. It's pretty much just oil. Not cold enough for condensation in southern California.

Just curious, which can?

 

[DavidR]

I'm not opposed to a catch can or questioning your choices, but if you think there is a need why not choose an Air/Oil Separator, which doesn't require manual draining? Is it just the cost?

From what I've read, it's also complexity. In colder areas where it will catch a lot of fuel/water condensation, you don't want that to be returned to the engine oil, so cans like that need to be heated, often requiring engine coolant routing, in order to further separate the oil from the fuel/water condensation. Again, not direct experience, just from what I've read. In the 2.3L Ecoboost engine, Ford solves that by building the separator into the engine block.

 

[RCMUSTANG]

Just curious, which can?

Look at my build thread. I detail it there.

 

[DavidR]

Look at my build thread. I detail it there.

That's a great build thread and a lot of cool mods! It's probably a lot more than I'll ever do but thanks for posting all that info, and I'm glad I caught the post about the upgraded coils - I've noticed the stumble when cold/ low acceleration and it's nice to know the coils will solve that - it's not horrible but it's definitely annoying and would be nice to get rid of. I'll probably go for the Forscan as well.

We've only had the truck for two weeks and I ordered a JLT can which is on its way. After some more reading around, it sounds like it might not be the best one out there and I'll likely upgrade it at some point, but at least I'll have the plumbing done, which is a PITA on this truck.

Even so, I'm surprised at the relatively small amount of oil caught by your Mishimoto can over 3000 miles. Maybe Ford actually has improved the stock PCV system. I still think it's worthwhile to catch the remaining amount.

 

[RCMUSTANG]

That's a great build thread and a lot of cool mods! It's probably a lot more than I'll ever do but thanks for posting all that info, and I'm glad I caught the post about the upgraded coils - I've noticed the stumble when cold/ low acceleration and it's nice to know the coils will solve that - it's not horrible but it's definitely annoying and would be nice to get rid of. I'll probably go for the Forscan as well.

We've only had the truck for two weeks and I ordered a JLT can which is on its way. After some more reading around, it sounds like it might not be the best one out there and I'll likely upgrade it at some point, but at least I'll have the plumbing done, which is a PITA on this truck.

Even so, I'm surprised at the relatively small amount of oil caught by your Mishimoto can over 3000 miles. Maybe Ford actually has improved the stock PCV system. I still think it's worthwhile to catch the remaining amount.

I don't think that's a small amount at all. That's a lot coating you intake and valves and burning off.

 

[Floyd]

Here's what I caught in about 3000 miles. It's pretty much just oil. Not cold enough for condensation in southern California.

Ambient temperature has little to do with crankcase condensation, It occurs much more as the result of very short trips with time between to allow temperature fluctuation.
Thanks for the photos, I see they are open to interpretation especially as to the effect of the volume produced.

Do you think you caught it all? If not, what percentage would you suppose?

If that oil had made it all the way to the intake, considering that it too is designed to separate oil, how much of that oil would have been returned to the crankcase?

What type of driving have you done?

Do you think that different driving habits produce different results?

How much oil over how long will produce enough deposits on the intake valves to affect performance?
Has anyone considered or studied the effect of the EGR strategy?

I have not yet met anyone with the complaint, on any EcoBoost, 3,4 ,or 6. Has anyone here?
I realize that would only be anecdotal, but it might at least add credence to the issue, provided some of the above questions were answered.

 

[RCMUSTANG]

The post can side is pretty dry. So, it catches almost all of it. Anything in the intake goes right into the combustion. There's no way for it to make it back into the crankcase. I do mixed driving for around 30 miles round trip. And a trip from LA to Phoenix and back. Either you're pulling it in through the pcv or the "breather" side when under boost. I've routed it to catch on both. So, if you drive it harder you'll probably pull more through. I'm pretty light on the pedal despite being mod heavy. I'm of the thought that an engine should not have oil introduced into the combustion at any point. Spending less than $90 on the one I put together is more than worth it.

 

[DavidR]

I don't think that's a small amount at all. That's a lot coating you intake and valves and burning off.

I agree, any amount is bad, it's just a lot less they you typically see in most videos and reviews for similar mileage runs

 

[DavidR]

How much oil over how long will produce enough deposits on the intake valves to affect performance?
Has anyone considered or studied the effect of the EGR strategy?

I have not yet met anyone with the complaint, on any EcoBoost, 3,4 ,or 6. Has anyone here?
I realize that would only be anecdotal, but it might at least add credence to the issue, provided some of the above questions were answered.

Those are good questions, and part of the problem is that there doesn't seem to be a lot of actual scientifically obtained data, at least not generally available (I'm sure auto manufacturers have done extensive internal testing). I was only able to find one research paper comparing various types of catch cans in any sort of scientific way (which I posted a link to earlier), but that doesn't answer the questions you have about actual rates of degradation.

This is the first vehicle I've had with a DI-only engine. My philosophy is that while much of the evidence out there is anecdotal, if the cost of even a good catch can (better than the one I ordered) is less than the cost of walnut shell blasting at 60K-80K miles, and if it reduces the gradual degradation of performance, it seems worth it given that the drawbacks are pretty minor and mostly just convenience related.

There isn't much that can be done about other sources of deposits such as EGR or oil leaked in through the turbine or valve guides, so a catch can, even if it catches all PCV oil, won't completely eliminate the problem, but if it pushes it from 60K-80K miles to twice that or more, it would be a big improvement.

 

[DavidR]

I've routed it to catch on both.

@RCMUSTANG , unless I missed a post, I don't recall your build thread discussing the connection to the breather (boost) side. Did you do that later on? The stock breather hose looks like it has a flow sensor or some other sensor in it. Did you have any issue with error codes when you put the can in? Did you use two hoses with check valves to provide the direct connection for breather air under non-boost conditions?

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