How would a catch can introduce moisture to the engine?
Or, how does a PCV system without a catch can remove moisture from the engine?

 

I have no idea, I don't claim to be an expert nor do I consider myself very technical savvy when it comes to the intricacies of an internal combustion engine. I am just relaying what the technician told me because I myself wasn't sure about the accuracy of his statement. But I guess he was trying to say that the introduction of the OCC reroutes the factory system and thus oil/moisture has been found in places it normally would not be. I'll try to ask for more specifics next time I talk to him but does anybody have a second opinion on this?

 

It doesn't reroute it, per se... the line still goes from point A to point B; you've just inserted something in-between.

 

What Fishbert said.
The crankcase fumes (oil and water vapor) will condense in the oil catch can for a number of reasons, for one, it is cooler, if it is located away from the engine, as recommended by the catch can manufacturers. Also, it is a suddenly larger volume in the crankcase vent line, which would slow the velocity of the vapors, encouraging any heavier components to drop out into the can.

Water vapor shouldn't be a problem with or without a catch can, if you let the engine warm to operating temperature. The water just boils off and is consumed by the engine. Just avoid very short trips. There is a reason they call it an oil catch can.

I don't think your technician really understands what the PCV system does.

Dave

 

I second what fishbert and DneprDave said. I think what the tech may have seen problems with were OCCs that used reduced-size plumbing or OCCs that were allowed to fill up. Either of these conditions could be worse than if the OCC wasn't installed in the first place.

 

This is a very accurate description of what the OCC actually does. I don't see how it could do harm but I am curious to see what others have to say. I just put mine in 3 days ago and already sucked out a little watery oil + particulate matter.

 

So are OCCs recommended for non-S cars as well? All the OCC threads seem to be in the S section. My 2008 seems to be still running fine at 60k with no seafoam or anything yet. The idle was never extremely smooth in either of my MINIs even when new.

 

No

 

Still nothing heard from these guys. I think BSH is missing out on a bunch of potential sales to '11 owners.

 

Gil-galad or anyone that has a 2011 MCS,

Have you installed an OCC yet?

 

OK, newbie here but would'nt this void the factory warranty ??? Now, I know it should'nt, but could'nt a dealer use it as an excuse to deny a warranty claim ???

 

No, it is just a large space, that encourages the condensation of oil and collects it, in the existing PVC system. It doesn't actually change the plumbing.

If you're worried, it isn't difficult to remove, before visiting the dealer.

Dave

 

Not yet. The PCV system on the '11 is sufficiently different that I'm not comfortable just hooking one into the single line between the valve cover and turbo inlet and assuming everything is going to work correctly. With no visible vent on the passenger side, I have no idea how the crankcase is ventilating itself under intake manifold vacuum conditions. Hard to believe that all of the crankcase gases are now being routed through the turbo.

I'm waiting for one of the vendors to get off their a$$ and offer a solution that has been integrated and tested with the N18 powerplant. No one seems interested in any business from the '11 owners right now.

 

I picked up my 2011 MCS on Tuesday. I'm glad I found this thread and held of ordering the BCS OCC after opening the hood for first time today. I've been busy. I did order the M7 reinforcing plates and strut bar today.

 

They don't have the 2011 model parts listed on the Real OEM site yet. http://www.realoem.com/bmw/select.do

But from what I've read, MINI eliminated the hose from the intake manifold to the connection on passenger side back of the valve cover. This put turbocharger pressure air into the engine, to help scavenge the crankcase of oil vapor.
It wasn't really needed, as there was already a hose from the valve cover to the turbo intake that already scavenged the oil vapor. This is the line that is recommended for the oil catch can installation.

To be sure that they didn't just relocate the pressure side hose, one of the owners of a 2011 Cooper S could just have a look and let us know.

You would have take the air filter housing off to get a good look, take pictures!


Dave

 

Realoem has had the 2011 parts online for quite a while, actually. They're listed under R56 LCI (life cycle impulse).

This is completely wrong.

The important line for the PCV system is the one directing crankcase vapors to the combustion chamber. This line is (by far) of greater concern when trying to prevent carbon buildup in the intake ports and on the back of the intake valves. In an R56 MINI, this line is the one on the passenger side that seems to have gone missing on the 2011s (that's why understanding its disappearance and how crankcase vapors make their way to the combustion chamber in the N18 engine is important before messing about with the PCV system).

The driver side line (coming from the cold air intake) is there to improve ventilation efficiency of the PCV system... and not much else.

 

Well, I'm certainly no expert but my understanding of the dual vents on PCV systems in turbo powered vehicles had to do with the fact of the varying intake manifold pressure.

I believe under non-boost conditions the crankcase is only slightly pressurized due to blow-by at lower rpms and the intake manifold is operating under a vacuum. This vacuum holds the PCV valve open allowing the manifold vacuum to naturally draw the crankcase vapors into the manifold and then into the combustion chamber, depositing icky stuff on your intake valves in the process.

Under boost conditions the intake manifold is under pressure from the turbo. To avoid back-pressure from the manifold into the crankcase, the pressure differential on the passenger side vent allows the PCV valve to close. Since now there is no vacuum in the intake manifold to draw the vapors, the vacuum source that is used is the intake pipe upstream of the turbo. The boost pressure differential allows the intake pipe to serve as the vacuum for drawing out the crankcase vapors. I understand the nasty crankcase vapors are produced at a much higher rate under boost conditions, but of course under normal driving one spends a lot less time with the engine under boost. In this mode, the icky stuff also gets deposited in your turbo, intercooler, intake manifold, and on the valves.

This feeble understanding may or not be fully correct but still leaves me with the question on the N18 as to where the crankcase vapors go under non-boost conditions.

 

I just looked again, the parts list for the R56 LCI ends at 09/2010, not 2011. Do you have another link to the 2011 parts list, I can't find it.

Completely wrong? That's a rather broad statement! I'm not wrong at all. That line, which connects the valve cover to the intake manifold, under boost, is feeding boost air to the valve cover, that is why BSH uses it as a boost port. It is definitely aiding crankcase scavenging. At lower power output, there will be a vacuum at that hose, drawing air and oil vapor into the intake manifold, where we don't want it. That's why we put the BSH dual boost tap on 2010 and older series two cars, because it blocks that line.

The other line that connects the other side of the valve cover to the turbocharger intake, is the PCV line. Which is why we put the oil catch can on that line. The turbocharger pulls air, oil vapor and water vapor out of the engine, then pushes it through the intercooler and into the intake manifold and the engine. The original intent of the oil catch can was to prevent oil from coating the inside of the intercooler, reducing its efficiency. It is good, for those of us with direct injection engines, that it also prevents oil from getting into the intake manifold and the intake ports.

It appears that on 2011 MINIs they have eliminated the boost line from the manifold to the engine, via the valve cover. That is why I asked any 2011 Cooper S owners, to take the air filter housing off of their cars so they can see if Mini has done away with the hose or just moved it.

Then, we'll know!

Dave

 

Dave,
Please read my earlier post in this thread on this issue. I confirmed with the Head Tech at Mini of Annapolis that the PCV line from the crankcase to the intake manifold was removed on the refreshed engines. This is confirmed by looking at Real-OEM and looking at the cylinder head diagrams and the "intake muffler" diagrams.

So now the PCV system on the refreshed engine operates exactly as the system on the older Prince engine WITH the BSH dual boost port tap (aka, line plug) operates. The air line going from the valve cover (on the drivers side) to the intake tube (just before the turbo) performs the PCV function. The air pressure in that line will always be lower than the pressure in the crankcase so the blowby gases will be sucked out (and shoved into the turbo and intercooler).

It seems to me that an OCC is absolutely called for. It will keep the slimy emulsified water/oil mixture out of your turbo and intercooler. I should note that my almost 15 months experience with a catch can says that it pulls mostly water with a small layer of scummy oil/water mixture out AND it does it mostly in cold weather. I hardly got anything out of my OCC during the warmer months. I get about 8 oz of stuff out every time I check (when I do a gas fill up -about every 400 miles) during the winter.

So is this PCV system optimal? The BMW engineers must think so. I like the idea of the system on my MCS engine where one line acts like a scavanging air supply (most of the time) and the other acts as the discharge line. But what do I know?

Cheers,
Greg

 

Agree with those on this thread that think a catch can would provide benefit on the 2011 N18 engines. Seems like business owners who sell Mini parts (like WMW and Alta) who participte on NAM would be all over this issue to develop a solution.

C'mon someone!

 

The whole point of the PCV system is to eliminate crankcase fumes by recycling them to the combustion chamber and burning them off.

The hose connecting the crankcase to the intake manifold (and thus to the combustion chamber) is the primary path for the PCV sytem. The hose from the cold air intake brings fresh air in, helping to make the PCV system more efficient (in the same manner as opening both the front and back door helps clear your house of smoke when the roast in the oven gets burned).

For the short periods of time that the engine is under boost conditions, this normal direction of air flow is reversed, which is why people find oil in their intercoolers. But this condition is secondary (by far) to the normal operating condition of the engine and the PCV system, which (as described above) direct crankcase fumes to the combustion chamber via the crankcase ventilation hose on the passenger side of the vehicle.

-------

DnperDave, I don't intend to get in a big argument in here with you over how the PCV system operates (though I certainly could if you like). Suffice it to say, your claim that the ventilation hose directing crankcase fumes to the combustion chamber "wasn't really needed, as there was already a hose from the valve cover to the turbo intake that already scavenged the oil vapor" is just plain wrong.

What Gil described in his recent post and what I wrote above the line is how the PCV system operates. The hose from the crankcase to the intake manifold is the primary PCV fumes path and is absolutely necessary if the engine is to burn off crankcase fumes (i.e., have a PCV system). The **ONLY** reason this path can be blocked off with (relative) safety by the BSH boost tap is because a catch can is inserted into the other line to collect those vapors instead of burning them. Without a catch can on that line, the crankcase fumes would not still make their way to the intake manifold (as you claim -- which would also lead to the question of how this design would do anything to prevent carbon buildup either), but would collect in the intercooler, its large interior surface area acting as the baffles of a catch can (one with no drain and that negatively impacts intercooler performance).

Exactly!

 

You are confusing build dates with model years.
The R56 LCI parts on realoem.com are for the 2011 model year R56 MINIs.

2011 model year R56s that were actually built in 2011 are only just now arriving to those who ordered them. If you go today and look at a 2011 in stock at your nearby dealer, it was built in 2010.

 

This actually makes some sense to me. Not sure how the pressure in the intake pipe changes under different loads, but one could imagine that the PCV valve in this configuration never completely closes. It merely changes how wide it is open based on the pressure differential between the intake pipe and the crankcase.

It also means that the blow-by gases are always passing through the turbo and intercooler, making installation of an OCC seem even more imperative. C'mon BSH -- are you not listening?

 

[quote=fishbert;3224493]The whole point of the PCV system is to eliminate crankcase fumes by recycling them to the combustion chamber and burning them off.

OK, you have that right!

The hose connecting the crankcase to the intake manifold (and thus to the combustion chamber) is the primary path for the PCV system. The hose from the cold air intake brings fresh air in, helping to make the PCV system more efficient (in the same manner as opening both the front and back door helps clear your house of smoke when the roast in the oven gets burned).

Nope, this is where you miss the point, it is a path, not the primary path. They don't even use it anymore on the 2011 MCS engines, see NAProf's post.

For the short periods of time that the engine is under boost conditions, this normal direction of air flow is reversed, which is why people find oil in their intercoolers. But this condition is secondary (by far) to the normal operating condition of the engine and the PCV system, which (as described above) direct crankcase fumes to the combustion chamber via the crankcase ventilation hose on the passenger side of the vehicle.

There is alway a flow of crankcase fumes from the driver's side of the valve cover to the turbo inlet, regardless of engine load. The other path, switches back and forth depending on load, or boost.

-------

DnperDave, I don't intend to get in a big argument in here with you over how the PCV system operates (though I certainly could if you like). Suffice it to say, your claim that the ventilation hose directing crankcase fumes to the combustion chamber "wasn't really needed, as there was already a hose from the valve cover to the turbo intake that already scavenged the oil vapor" is just plain wrong.

Don't worry, I am loving this discussion, please continue! I know that I am correct and you are mistaken. So tell me, why did MINI's engineers delete the "primary" PCV line for the 2011 models?

What Gil described in his recent post and what I wrote above the line is how the PCV system operates. The hose from the crankcase to the intake manifold is the primary PCV fumes path and is absolutely necessary if the engine is to burn off crankcase fumes (i.e., have a PCV system). The **ONLY** reason this path can be blocked off with (relative) safety by the BSH boost tap is because a catch can is inserted into the other line to collect those vapors instead of burning them. Without a catch can on that line, the crankcase fumes would not still make their way to the intake manifold (as you claim -- which would also lead to the question of how this design would do anything to prevent carbon buildup either), but would collect in the intercooler, its large interior surface area acting as the baffles of a catch can (one with no drain and that negatively impacts intercooler performance).

One problem with Gil's description is that the MCS doesn't have a PCV valve, that is something that is necessary on a normally aspirated engine, to prevent a massive vacuum leak, not a problem with a boosted engine.

The way the crankcase fumes get to the intake manifold with the breather to the intake manifold blocked, is the same way all the air get to the intake manifold, through the turbo, intercooler and into the intake manifold.

As you said, the intercooler makes a great oil catch can, that's why we put an oil catch can in the PCV line before it gets to the turbo.

Just look at it, I don't understand how you can't see it.

Dave

 

I can't honestly tell if you believe that or are just trolling the thread.

You seriously believe that, instead of taking a direct route to the intake manifold (as was already on the car before), BMW/MINI has redesigned the 2011 MCSs to first push those oil-laden crankcase fumes through the turbo and intercooler instead?
How would that be any kind of improvement over the previous design?!
Are you even listening to what you are saying?!

The PCV system isn't some MINI-specific invention that nobody else has. Pretty much any car made in the last couple decades has a PCV system as part of the engine design. In all of these systems, crankcase fumes are directed to the intake manifold ... and in some of these sytems, an additional airway is added to the cold air intake to improve the ventilation efficiency of the PCV system (but this second hose to the CAI is not necessary). And furthermore, having a turbo at all has ABSOLUTELY NOTHING TO DO WITH THE PCV SYSTEM!

Also, the PCV valve function is built into the valve cover on the MINI. It's not just some simple plastic hat on the engine head.

Here, this series of videos on what a PCV system is might prove helpful to you (and others reading this discussion).
http://www.youtube.com/watch?v=rs6YtHUscCA