Oil Catch Can. Yes or No?

[Wschnitz]

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.

Unless its a Rotary, then its Pre-mix or death.

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[RCMUSTANG]

Unless its a Rotary, then its Pre-mix or death.

Apples and oranges.

 

[RCMUSTANG]

@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?

Yeah, I did it later. I'd have to post updated info. It's complicated looking and takes a bit of thought to get it sorted out with a single in/out can. I used one check valve and plumbed after the sensor. No issues.

 

[DavidR]

Yeah, I did it later. I'd have to post updated info. It's complicated looking and takes a bit of thought to get it sorted out with a single in/out can.

OK, look forward to seeing it, and thanks in advance for posting any description. I'm pretty light on the throttle, so maybe the manifold-side connection is good enough for me, but I do carry a 1000-lb pop-up camper at times, and it will probably be in boost a lot more when that's on, so might be good to protect the boost side as well. I've just been wondering how to do it correctly and if the flow sensor presents any issues.

 

[Floyd]

Every good study requires a control, for now at least I will fill that position.
I think the Ford system is adequate and certainly well thought out.
I will keep clean fuel,oil and injectors and will try and report back here in 7 years if all is well at 100,000 miles,
earlier if problems develop.

As for the cause of intake valve carbon deposits...
I assume we agree that the problem is blamed on direct injection and not exclusively to crankcase ventilation.
Personally I think that the EGR strategy tied to variable valve timing would prove to be as culpable as PCV.
That is if there proves to be anything to be culpable about.
We've had nearly a decade of experience with direct injection on EcoBoost as a spring board and very little data on intake valve carbon deposits.
In addition we have seen both improvement in PCV and the reintroduction of conventional MFI.
The reason for the former is obvious.
The reason for the latter is not so much and is officially not intended to address intake valve carbon deposits.
In ten years I will be adequately satisfied as to the facts, or sooner if more information is forthcoming.

The PCV system on the 2019 Ranger is pretty impressive and surely expensive to develop and produce.
Are we to believe that Ford saw the problem and didn't address it at the cost of a simple catchcan or a separator?
With the reputation of the best selling and most profitable vehicle in history at stake?
Are we to suppose that the catchcan developer was that far ahead of the curve or had more experience than Ford who simply does not have the talent or experience to develop a solution which has been so easily found?

If the valve problem as described and the cause is accurate, then a single intake injector for enrichment at cold startup (like VW of 3 decades ago) would solve it far more effectively and could be produced at the cost of a separator.

Not addressing a serious known problem would be far more costly than the few cents it would cost.
An ounce of prevention is still worth a pound of cure, no matter which side is right.

In the mean time we must hope and suppose that a catchcan will do no harm and perhaps even mitigate the issue. The caveat being that it is properly installed and adequately maintained.

 

[RCMUSTANG]

It's not a "serious" problem. Any system with a pcv will draw in oil into the intake and therefore end up going down the line. I just don't like to have any oil mixed in with my air/fuel on any of my vehicles, DI or not. The valves are a secondary reason for me. You'll probably only see separators on higher end or performance vehicles. Not mass produced commuters.

 

[DavidR]

As for the cause of intake valve carbon deposits...
I assume we agree that the problem is blamed on direct injection and not exclusively to crankcase ventilation.
Personally I think that the EGR strategy tied to variable valve timing will prove to be as culpable as PCV.
That is if there proves to be anything to be culpable about.

I think there are a lot of good points you make. As you mentioned before, a lot of the evidence of problems is anecdotal, and I admit I have generally seen more reports of problems with earlier DI engines from Volkswagen, BMW, etc., but there have been some reports of Ecoboost engines with valve coking problems as well.

Yes, there will be other sources of valve deposits, like EGR and maybe even leakage around valve stems and turbo bearings, especially as the engine ages, but the PCV system seems likely to be a significant contributor. Even if it accounts for only half the deposits, getting mostly rid of it would at least push the problem (if there is a problem, as you say) out twice as far in mileage.

In my mind, I think it comes down to cost-benefit. If the cost of a separator is relatively low, which they are (the most common ones are under $450) and there are no technical downsides, only some minor inconvenience, then it seems to make sense to add it. Like you point out, a lot depends on other things, like frequent oil changes with high quality oil, using top tier fuel, keeping the injectors clean for optimum combustion, balancing out short stop-and-go trips with longer ones, etc. An oil separator just adds to those for relatively little cost. Everyone will fall in a different spot in that cost-benefit trade-off and that's fine.

From what I've heard, port injection is being reintroduced mainly to help with certain emissions issues, possibly particulates, and not just to address valve deposits. Helping with deposits will be a side benefit, but our versions of the 2.3L engine have missed that boat, if it ever happens.

 

[Kataphrakt]

It's almost like we need a society of engineers from the automotive industry to do some testing on how much impact the PCVs have on buildup... oh wait...

Here is a good video presenting some info on an oil catch can.



The study he references is from SAE: "Formation of Intake Valve Deposits in Gasoline Direct Injection Engines" In their study they tested the same vehicle and experimented with the impact of the PCV system on engine valve buildup. They started with a baseline test to prove they could get consistent engine buildup through their test methods, then went on to testing the PCV. To test the impact of the PCV they vented the gas from the PCV into the atmosphere. Their conclusions are:

• Higher engine-loads lead to an increased rate of deposit formation.
  
• IVD formation in this protocol is an oil-related process, and the majority of the oil that finds its way onto the intake valves comes from the PCV system.
  
• The oil leaving the crankcase through the PCV system is whole oil containing additives and contaminants (not distilled base oil vapor which contains no additives).
  
• PCV gas flow in the intake manifold is inconsistently distributed among the eight runners of the manifold leading to the valves.
  
• Inhibiting the carbon-formation process lessens the rate of deposit formation on the intake valves.
  
• Oil consumption past the rings bring both additive and nonadditive elements into the combustion chamber where they are incorporated into the exhaust-gas particles.
  
• Particles found in EGR exacerbate deposit formation rate
  
• Particles found in EGR appear to incorporate combusted oil additive components, engine wear metals, and ambient air contamination.

The graph of their findings, basline testing vs venting directly to atmosphere.

From here the real question now seems to be "How well does a catch-can actually remove oil/etc from the PCV?"

For anyone who wants the info on the SAE article you can find that here but may or may not be able to access it. I used my University's library to read the article.

EDIT: Also with their point: "Oil consumption past the rings bring both additive and nonadditive elements into the combustion chamber where they are incorporated into the exhaust-gas particles." I'd also say that more frequent oil changes would help since the crap in you oil is part of what gets onto your valves, even without a PCV.

 

[RCMUSTANG]

From the amount that mine has caught, I feel more than justified in running it. Percentage wise, how much it catches? I would say at the minimum 75% as a conservative estimate. The hose that leaves the catch can remains pretty dry. So, I would say closer to 95% oil stopped. I'm happy with that for an investment of less than a $100.

 

[Floyd]

So, consensus is ...that despite the unique and maybe arcane PCV system devised for this application by Ford...,it is inadequate?
Implying that Ford is not competent to solve a problem which could easily be eliminated with the installation of a simple catchcan?
Another possibility is that they conspired to limit the longevity of the engine to enhance repeat sales.
Would you buy another if it was designed to fail at 80,000miles?

Accepting this consensus leads to two inevitable conclusions...

1] The addition of a catchcan is prudent, if not imperative.

2] The purchase of a new Ranger may have been ill advised.

 

[RCMUSTANG]

Ford counts pennies at the bottom line. Weighing the amount of deposits that accumulate over the life of the engine vs actual repairs because of them will come down to dollars. The acceptable decline in performance due to deposits is acceptable to most manufacturers. Again, high performance or higher end lower production number vehicles may decide it's worth not. Generally not mass produced by the hundreds of thousands to millions. Nobody is forcing anyone to run one. That's your preference. Many people don't keep cars as long as they used to. 99% of the people won't notice or will even be aware or care about this issue. Lot's of people will trade in or sell shortly after 100,000. It's the disposable mentality most people have. Eh, I'll just get a new one vs fixing stuff now a days. There clearly is a benefit to running one. How great a benefit depends on you. How long you keep it, whether you care about it or not, etc. No one is saying that you'll destroy your engine by not running one.

 

[Kataphrakt]

So, consensus is ...that despite the unique and maybe arcane PCV system devised for this application by Ford,it is inadequate?

Considering that ford is moving from DI to a combination of DI and PFI, yes.

Implying that Ford is not competent to solve a problem which could easily be eliminated with the installation of a simple catchcan?

I am not claiming Ford's engineers to be incompetent or incapable of solving the buildup issues PCV systems cause, those are all your words. Adding more parts to a vehicle which then need to be serviced regularly, and which were never present in previous vehicles would be the equivalent of marketing suicide in the US. Many people dont like to bother maintaining their vehicles, that's why the oil change industry is so big for a task which is so easy on nearly every vehicle. Heck, just look back on the outrage people had over needing to remove three screws to access the oil filter on the ranger!

As someone else mentioned, a separator costs around $450, when we're talking car parts that's a significant cost for something which then has to be maintained and for little perceivable benefit to the 5-year owners. While Ford's engineers do their best to put vehicles into production that will last decades, their marketing team; however, does their best to make sure those only last 100k miles. The perfect case-study is the PTU on the Explorer. Original production did not require that the fluid in the PTU be changed. This was because the engineers said "The fluid needs to be changed every 100k miles" and marketing's reply was "100k miles? that's the lifespan of the vehicle! drop it from the maintenance tasks" The drain port was promptly moved to the most asinine location requiring you to lay under the vehicle and reach shoulder-length upwards into the engine bay to find a port that you can only see from above, not below (Yes, i have done this, it sucks). After complaints rolled in about needing to drop the entire sub-frame to replace the PTU after only about ~150k miles there was a model-year refresh in which the drain port for the PTU got moved somewhere serviceable and changing fluid in the PTU every 100k miles became a PM task. (And if you'll note the Ranger's manual also lists changing the PTU fluid, but at 150k miles)

Solving the issue with an additional injection method instead of adding parts that need regular service is an obvious choice, it quite possible also costs less than a separator. There's also the concerns about emissions with any additional system you hook up to the PCV. You have to make sure the entire system is sealed to prevent any of the gasses from being released (otherwise the whole point of the PCV is lost) and for a catch can in particular, how do you make sure it's evacuated of gasses before the user removes the reservoir releasing all the contaminants into the air?

 

[Floyd]

Ford counts pennies at the bottom line. Weighing the amount of deposits that accumulate over the life of the engine vs actual repairs because of them will come down to dollars. The acceptable decline in performance due to deposits is acceptable to most manufacturers. Again, high performance or higher end lower production number vehicles may decide it's worth not. Generally not mass produced by the hundreds of thousands to millions. Nobody is forcing anyone to run one. That's your preference. Many people don't keep cars as long as they used to. 99% of the people won't notice or will even be aware or care about this issue. Lot's of people will trade in or sell shortly after 100,000. It's the disposable mentality most people have. Eh, I'll just get a new one vs fixing stuff now a days. There clearly is a benefit to running one. How great a benefit depends on you. How long you keep it, whether you care about it or not, etc. No one is saying that you'll destroy your engine by not running one.

So you adhere to the consensus and concur with my post?

Nobody forces me to do anything.

After I'm convinced by empirical evidence of the possible need, I will install one.
After I am convinced that it is effective, I will endorse its use.

Keep this thread open for a few years,...
Skepticism is not the same as rejection.
Some folks are just convinced on less evidence than others.

 

[RCMUSTANG]

Again, look at what mine caught in about 3000 miles. Is that more or less than you want to go through your intake and down the line? That's a hundred times more than I would want. I've run these for probably 20 years. N/A to blown. Never liked the idea of oil coating my intake and everything else along with burning it.

 

[Kataphrakt]

So, consensus is ...that despite the unique and maybe arcane PCV system devised for this application by Ford...,it is inadequate?

I think it's also worth pointing out that Ford sells a catch can for the 2.3l ecoboost engine.

Accepting this consensus leads to two inevitable conclusions...

1] The addition of a catchcan is prudent, if not imperative.

2] The purchase of a new Ranger may have been ill advised.

And of course, a strawman argument. because clearly we're all saying your engine will explode in 2000 miles if you dont use a catch can. You also neglect a scholarly article published by SAE, as well as literally every consideration that goes into the engineering design process and the marketing process, aside from simple function.

After I'm convinced by empirical evidence of the possible need, I will install one.
After I am convinced that it is effective, I will endorseits use.

A) The previously mentioned SAE article that shows any connection of the PCV to the intake contributes significantly more intake valve buildup than the EGR does.

B) The previously mentioned SAE article that shows the presence of PCV to the intake compounds the issue of EGR

C) The fact that a simple catch-can is able to catch anything after Ford's brilliant PCV system?

D) The following video about this exact carbon buildup issue with ecoboost engines:

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