Ultimate Catch Can solution idea

[Spike00513]

Here is the information I have come up with so far. This may or may not apply to the 1.8T.

(All of the following information is theoretical as far as I'm concerned)




The B6 3.0L has a PCV system which has at least 2 functions:

-When the engine is up to temperature, the oil stays liquid while the water vaporizes. In order for the water to escape, there must be a PCV system in place. If the water can't escape, it will make the oil acidic. I don't know where this water comes from but I have read that it is from blow-by (gasoline has water in it) and condensation.

-Prevent excess crankcase pressure, which can blow seals and what not




Oils don't all have the same vaporization point. A cheap, low-quality dino oil that hasn't been changed in 15k miles will vaporize easier than a high quality oil with 5k miles, let's say Shell Rotella T6 or Motul 8100 X-Cess 5w40. For this reason, you don't just get water vapor escaping through the stock PCV system, into the intake, to be re-burned. You also get "oily aerosols" as Diagnosticator put it. I am guessing that with a high quality oil you will get less of these aerosols. My 3.0 intake tract, at 100k mi, is completely covered in what appears to be "oily aerosols". Maybe this is because the previous owner infrequently changed the oil with cheap dino oil. But then again, intake tract/carbon build-up is a hugely prevalent issue amongst VAG cars, namely the B7 chassis. Sure, we don't have the intake valve carbon build-up of a B7 RS4 but that is because they have direct injection, whereas we have port-injection (gas constantly sprays and cleans the intake valves). But the build-up still remains on other surfaces that don't get cleaned. Such as the intake manifold (in my 3.0).

What I am trying to do is clean my intake manifold, and keep it clean. The general consensus is that the Mann ProVent 200 is the best thing since sliced bread, so I'm inclined to go with this for a catch can set-up.



My questions are:

-Am I going about this the right way? Maybe cleaning my intake manifold once, and using good oil from here on out is the solution?

-If I should go with the Mann ProVent 200, how should I route it? Some suggest routing the drain to the crank-case/sump. Others suggest putting a filter on it and letting it go to atmosphere (doesn't make sense because there's liquid). Others suggest capping off the drain, then manually draining it every once in a while.

The less I have to touch the car, the better. I have a cheap eBay catch can. I'm thinking, maybe I can route the Mann ProVent drain to a "secondary catch can", so that I don't have to empty out all of the "crap" so often? ("crap" meaning oil/water, etc. that is collected by the catch can/caught by the filter).

Anybody running a similar set-up?


MK4 TDI installation write-up: http://forums.tdiclub.com/showthread.php?p=846480

Differences between real and fake China "Mann ProVent 200": www.carformance.com.au/hp200

Mann ProVent brochure: https://www.google.com/search?q=Mann...x-a&channel=sb


Mann ProVent 200:



eBay secondary catch can, to which the ProVent would drain to:




Although Mann says it is possible (and seems to recommend) routing the ProVent drain back to the sump/crank, I am not sure if this is healthy for the motor. I say this because those who use the ProVent report that it collects water. If this is the case, then why drain water back into the oil, which contaminates it and makes it acidic? Isn't that one of the main reasons for the stock PCV system in the first place - to get rid of water?

IF manually draining the ProVent (or a catch can that the ProVent drains TO) is the solution, might there be any issues in climates where water freezes? The ProVent has a sort-of emergency pressure relief valve. Meaning that if the filter were to get clogged, the valve would open, thus keeping the engine from building excess pressure and exploding. It would vent to atmosphere, get the engine bay messy, and hopefully you would notice in time to resolve the issue.

I take it that another "pro" of the ProVent is that with no more oil being burned, catalytic convertor life is increased.

[Spike00513]

So basically, it would look something like this:



But I'm unsure of a few things. Such as:

If I drain it to the crankcase, and use an in-line check valve (part no. 2400843621) like Mann suggests, would I be plumbing pure oil back into the crankcase? Or water(bad)? I assume I would have to clean all plumbing(hoses, etc.) thoroughly prior to installation, if draining to crank.

This would be convenient because I'd never have to manually drain the catch can - just change the filter every 50k miles. Whereas with a manual drain, I think you need to drain it every oil change.


If water collects in the ProVent, I guess those of us in cold climates could simply mount it close to the engine, so that the engine warms up the ProVent and melts the ice.

My main worry is whether or not that water goes back into the engine, or is burned like it's supposed to be.


I can't help but notice that BMW E46's come from the factory with oil separators, similar to this Mann ProVent, that drain into the crankcase via the oil dipstick tube.



Factory B6 3.0 dipstick tube:



Maybe I could drill/tap into the factory B6 dipstick tube, and weld/modify it to be like the BMW one.

Seems like most people who run catch can use hoses for the plumbing, such as heater hose. No matter what kind of hose you use, it will eventually deteriorate. Maybe a solution is to use metal piping and add some bling to the engine bay.



Mann ProVent video starts at 8:20

[SlickFix]

This looks very interesting. Some random questions, though:

1) Is what they call the CCV Puck, our PCV valve?

2) If so, that means the PCV valve would connect to the intake of the Pro Vent. The output of the Pro Vent would go to...where exactly on the intake tract?

3) Where is there enough space in our engine bay to install this setup, and would you have to remove it to do other repairs?

I have to admit, the current PCV system of the 3.0 seems to be woefully inadequate.

[SquiddyB6S4]

This all sounds like an excellent thought process. Please allow me to think out loud.

For starters, I see this thing separating out some of the sludgy vapors; catch cans always seem to catch some funk inside that you don't really want bank inside the crankcase. I figure this is probably because of their lack of proximity to the engine - oil turns to coke when it gets very hot and is allowed to stagnate and cool. If you keep it moving and warm, it will stay in oil form. But either way, most of what you catch in the can should stay as oil that you would have rather had back. Mixing the coke and the oil probably means that you don't really want it back. So I'm seeing a little test, if you don't want to touch it that often: install without dropping it back into the crankcase, monitor weekly, figure out about how long it takes to fill up, then get an appropriately sized overflow bottle to hold the liquids for the amount of time you don't want to touch it. Or just drain it; it shouldn't take long, especially if it has a drain petcock on the end of a hose that conveniently is fastened to the sound pan, so you can quickly open, drain, and close.

Alternatively, and probably better, situate this thing close to the block and NOT the exhaust, to try to glean warmth from the engine and keep the oil inside toasty and fluid. This would also help drain-back, and it would help burn off the thinner compounds, such as water and fuel. I vote this as the best case scenario for installing a catch can. Tying in to the dipstick tube might not be optimal, as you will probably want something more vertical and direct, to promote draining. I would think that more liquid built up in there unable to drain, such as drain tube above the bottom of the vessel or drain tube/hose with local high points instead of being fairly vertical, would be worse, since it would allow liquids to build up and except for longer drives, they wouldn't get warmed completely.

For the intake piping, once you install a catch can that does not feed back into the inlet, your oily issues will be all but gone. However, how much power do you think you might be losing from said build-up? What you have in your intake piping looks bad, but does it really rob performance? Does it really cause a maintenance issue? I have had multiple cars surpass 200k miles easily that had never had these build-ups cleaned. None were German made, of course; all Japanese.

Have you run used oil analyses at all? There is a part of the report that should show water content; mine has always been extremely low or non-detect with factory PCV. I would collect a before and after, with similar mileage and usage styles, to see if what you install works as intended.

I know the FSI 4.2 has a decent PCV system in it, with swirl pots and whatnot, that does return the oil to the crankcase. Perhaps that's another easy answer? The filter on the ProVent would probably start building up with tiny particulates quickly is my guess, so it would actually help filter out the gummy stuff and allow only actual liquid oil and water through, though possibly it would leach contaminants from the caked on stuff as it passes through.

But furthermore, if you vent this thing to atmosphere instead of the engine, you will be losing the scavenging effect of the PCV system. It's not just intended to allow pressurized gasses to escape; it's designed to forcibly remove them, presumably to reduce windage. It will greatly increase the collection rate, but I don't see where a properly designed system would have a huge problem here. To go back to the FSI PCV system, it swirls out the material to return to the crankcase and disposes of the vapor (to the intake) that doesn't filter out. The valve covers in probably every import engine I've seen made since the 90's also have a trap in the top, to help drop out liquids. I know this can be done effectively because my S4 has never consumed enough oil in 5k miles to be visible on the dipstick, and it's on the factory, simple PCV system. And my oil analyses have been quite good.

So I guess what I am getting at is this - what's wrong, exactly, with the factory system? At least to me it appears to do a decent job. Yes, it causes some build-up in the intake manifold, but I have had many cars run on the dyno with very high mileage that still made the same or nearly the same power as when new, with other maintenance done and the build-up left in place. In whatever case, if you are bent on installing something, I would think that keeping it warm and close to the block with a return to the crankcase would be the best.

[SquiddyB6S4]

I have to admit, the current PCV system of the 3.0 seems to be woefully inadequate.

Is this because it's old and not working well? Forgive me not knowing the difference and not caring to look it up, since I don't own one. Many S4's suck oil through the PCV system, but there have been many, many S4's lately getting new, OEM PCV valves, which have essentially stopped their oil consumption issues. Just a thought. Early valves were prone to freeze damage, apparently, and later ones have been said by some to be more stout, but either way it's still a paper diaphragm in a plastic housing. It's not a forever part.

[SJorge3442]

Is this because it's old and not working well? Forgive me not knowing the difference and not caring to look it up, since I don't own one. Many S4's suck oil through the PCV system, but there have been many, many S4's lately getting new, OEM PCV valves, which have essentially stopped their oil consumption issues. Just a thought. Early valves were prone to freeze damage, apparently, and later ones have been said by some to be more stout, but either way it's still a paper diaphragm in a plastic housing. It's not a forever part.

these are popular with mustang owners and many wont run their cars without them. Wouldnt something this similar work for us? http://www.americanmuscle.com/jlt-bl...or-0509gt.html

[SlickFix]

Is this because it's old and not working well? Forgive me not knowing the difference and not caring to look it up, since I don't own one. Many S4's suck oil through the PCV system, but there have been many, many S4's lately getting new, OEM PCV valves, which have essentially stopped their oil consumption issues. Just a thought. Early valves were prone to freeze damage, apparently, and later ones have been said by some to be more stout, but either way it's still a paper diaphragm in a plastic housing. It's not a forever part.

In my 3.0, even with a completely new PCV system, the "yellowish gunk" still seems to accumulate on the inside walls of the breather hoses. I don't know whether the Pro Vent would prevent that or not, but it would be nice to find something that would.

My S4's PCV seems to be okay for now, no real oil consumption to speak of. But I do get the "chain rattle" on cold starts, though.

[Spike00513]

In my 3.0, even with a completely new PCV system, the "yellowish gunk" still seems to accumulate on the inside walls of the breather hoses. I don't know whether the Pro Vent would prevent that or not, but it would be nice to find something that would.

My S4's PCV seems to be okay for now, no real oil consumption to speak of. But I do get the "chain rattle" on cold starts, though.

If you hook up the ProVent after the PCV, but before the intake, I do not think this would put a stop to the yellowish gunk building up in the PCV breather hoses.

In my above illustration that I found on TDI club, the "CCV Puck" = our "PCV Valve".

One place we might be able to put the ProVent is in the TCM cubby hole. Or re-locate the battery, and use that as a spot for it. There may be other places, I haven't really dug in. We may not have to remove the ProVent to do other repairs, probably just any hoses/piping, which shouldn't take more than a few minutes to remove. If it is something that calls for ProVent removal, it shouldn't be that hard to take it out. Most likely, the ProVent will be held in position by a a detachable bracket of some sort - possibly held on by just two screws. Maybe it would even fit somewhere behind the firewall and not necessitate battery relocation. I know at the very least, chafing will have to be kept in mind. Over time, if the ProVent hoses were to rub against other hoses, they would tear.

Here is where I think you could connect the outlet of the ProVent. Underneath the plastic tray (3.0L) at the back of the manifold, you will find your throttle body. Next to it, there is a thick, maybe .75in diameter hose, 2 inches long, with a 90 degree bend. This hose attaches to the PCV outlet, and connects to the intake manifold. I think this hose is what you would "intersect" with a ProVent.

[BARRY]

this is such a cool idea...i wish someone would make a steel one or billet one for our cars with the same drain back functionality.

[Spike00513]

I am not sure at which pressure the 3.0 PCV is designed to open up at, but it seems like a poorly functioning system, on it's best day. Best day meaning that all parts are functioning as intended.

The B6 3.0 PCV valve can be had for $20-$120. To me, it looks like a simple pressure relief valve. However, the B7 RS4 PCV valve/oil separator looks much more elaborate and costs around $300.

I'll have to check the SSP for B6 3.0 PCV information. I can't find any on Mann's website. Here is a picture of the B7 RS4 set-up. AFAIK, it doesn't do its job on the RS4, but it is still looks more elaborate than the B6 PCV valve.

[IMG][/IMG]



I have a new PCV valve, and inspection of it, I see that there is oily residue inside of it. Which leads me to believe that although I run good quality oil, "crap" still gets up into the intake. Even though my PCV system is intact and working as intended.

I think the 4.2L B6 S4 may have a different set-up, I'm not sure.

[Spike00513]

...

Would coke even apply to my 3.0L? I try not to drive it hard, and I would think that the oil in it doesn't get stressed as much as a twin turbo B5 S4 V6 engine, which I think has the same or similar oil capacity. I don't have those two super hot turbos to coke my oil. From what I've been told by a few B5 S4 owners, although there is great stress on the oil, it won't turn into coke as long as you let the car properly cool off after beating on it. I doubt my 220CHP 3.0L runs as hot, and if I do romp on it, I make sure to let it cool off.

I have never ran any oil analyses. I am thinking of doing that to get an idea of water content. I understand that a stock PCV system is supposed to get rid of water and does that job well. That is not my concern. My concern is oily build-up on the intake tract and valves. I am worried that if I hook-up a drain back to the crankcase, that not only would it re-cycle oil, but water as well. Diagnosticator and Old Guy both suggest draining to crankcase. I can't help but worry though, as I am not 100% sure myself whether or not the water vapor would get recycled and burned in the intake (like it should be), or sent back into the oil(bad). The reason I even think about this is due to posts like these:

Mann ProVent 200, 10k mi drain collection (drain every 2k miles)



I do not plan to vent the ProVent to atmosphere. I have read many accounts of this causing poor idle and loss of power, and I agree that this would cancel out the scavenging effect of the PCV system.

If it means anything, my 3.0L consumes enough oil to be visible on the dipstick if, and only if, I romp on it a bit. Meaning a few fast cruises, or occasional italian tune-ups. In the few times I have done that, oil level dropped by .2-.5L.
But if I drive normally, oil level stays the same on the dipstick.

I'm not sure whether the ProVent is even a solution or not, but I am bent on keeping my intake tract clean. I had to spend a day soaking my intake valve deposits in B12 Chemtool and then scraping them away with a pick. It wasn't fun, and my method was only 70% effective. I'm sure I could just remove my intake manifold, spend a day cleaning it with a brush (seems ineffective) or spend $150 on getting it ultrasonically cleaned. And I could build a walnut-blaster for the intake valves. But if I can avoid all that just by spending $150 on a catch can set-up, I'd rather do that. If you compare the costs of intake cleaning vs. build-up prevention, it pays for itself.
Sure, if 300,000 miles of normal operation makes zero difference, I would not spend a dime on trying to improve the PCV system. However, after I cleaned my intake tract (which I assume was dirtied by the PCV), the car felt much smoother both at idle and when driving. MPG seemed to improve but only by 1 or 2 mpg. Yes, the car will probably be driveable past 200k if I keep it this way, but I would like this car to last 400k mi + and feel almost, if not just as smooth as it was when new.


Are you suggesting I retrofit a 4.2 FSI PCV/oil separator instead of the ProVent?


Why situate the catch can by the block and not the exhaust? Because the exhaust would be way too hot? You say keeping the catch can nice and toasty would help oil drain-back (I agree) and help burn off thinner compounds, such as water and fuel. How would it help burn them off? By keeping them in vapor form so they can pass through the filter media, while the oil condenses and sinks? This is my biggest concern - whether or not vaporized water, fuel, etc. will be sent through the intake to be combusted, or simply condense and get drained back into the crankcase(bad).

[BARRY]

the FSI oil separator although is a great design, still doesn't work all to well. hence why RS4's need their intake tract cleaned out every so often.

[BARRY]

ixizAOSep, ixiz Air Oil Separator

this is the catch can, air oil separator I have for my motor whenever it gets built. it isn't as popular as the others due to pricing and capacity, but i've yet to see one that works as well as it does. it honestly needs a revision and a lower price. the main things that need improvement are port size and flow capacity. the flow of this unit could be limited once a turbo motor goes larger than a GT30R.

[koolade9]

Squiddy nailed it on his post, I want to expound on this part:

But furthermore, if you vent this thing to atmosphere instead of the engine, you will be losing the scavenging effect of the PCV system. It's not just intended to allow pressurized gasses to escape; it's designed to forcibly remove them, presumably to reduce windage. It will greatly increase the collection rate, but I don't see where a properly designed system would have a huge problem here. To go back to the FSI PCV system, it swirls out the material to return to the crankcase and disposes of the vapor (to the intake) that doesn't filter out. The valve covers in probably every import engine I've seen made since the 90's also have a trap in the top, to help drop out liquids. I know this can be done effectively because my S4 has never consumed enough oil in 5k miles to be visible on the dipstick, and it's on the factory, simple PCV system. And my oil analyses have been quite good.

My primary concerns are around the overall crankcase pressure level. Part of plumbing the PCV back into the intake is to apply vacuum to the crankcase. While venting to atmosphere seems like a good idea in theory, it's difficult to get proper flow out of the rocker covers without some type of vacuum assist. Over the last month actually, I've tried multiple setups on my 2.3-16 in an effort to keep oil residue out of my CIS system & idle air controller. The only way I could keep from blowing the dipstick out (too much crankcase pressure) was by hooking it back into the air box with the catch-can in-between. I'd be leary about applying too many things in that path (including long hose runs), as all those bends and turns reduce flow...just food for thought.

On the RS4, I'm looking to replace the oil separator (PCV valve) with a modified version that dumps any fluids back into the crankcase using the oil return line that the separator used, and providing better flow from the rocker covers to the intake manifold. I am of the opinion that some of the valve seepage, and subsequently some of the carbon build-up (some...not all) on the valves is attributed to the excess crankcase pressure. I'm sure the OEM oil separator works great on a fresh motor, but as valve seals wear in and blow-by starts to increase over time, the PCV can't keep up... Again, this is my opinion...take it for what it's worth.

[SquiddyB6S4]

Would coke even apply to my 3.0L? I try not to drive it hard, and I would think that the oil in it doesn't get stressed as much as a twin turbo B5 S4 V6 engine, which I think has the same or similar oil capacity. I don't have those two super hot turbos to coke my oil. From what I've been told by a few B5 S4 owners, although there is great stress on the oil, it won't turn into coke as long as you let the car properly cool off after beating on it. I doubt my 220CHP 3.0L runs as hot, and if I do romp on it, I make sure to let it cool off.

Yes, I think it may. I don't know what kind of internal temperatures Audi runs on the V6, but the V8 runs hot compared to other engines. Germans like to do that because it technically raises efficiency. Tell them what you want about making more problems than it solves; it's superior German engineering and you will buy it because it's superior. (that last part said in my best German/Ahhhnold impression)

I have never ran any oil analyses. I am thinking of doing that to get an idea of water content. I understand that a stock PCV system is supposed to get rid of water and does that job well. That is not my concern. My concern is oily build-up on the intake tract and valves. I am worried that if I hook-up a drain back to the crankcase, that not only would it re-cycle oil, but water as well. Diagnosticator and Old Guy both suggest draining to crankcase. I can't help but worry though, as I am not 100% sure myself whether or not the water vapor would get recycled and burned in the intake (like it should be), or sent back into the oil(bad). . . .

Don't you have a simple catch can now? You could set it up to drain back into your crankcase for a couple thousand miles and take an oil analysis, and that would help you know whether you are putting water back in. I doubt you will; water vaporizes easily at the temperature of the oil, so I am thinking that the reason everyone says it isn't an issue is because the vapors flow right back into the intake tract.

Why situate the catch can by the block and not the exhaust? Because the exhaust would be way too hot? You say keeping the catch can nice and toasty would help oil drain-back (I agree) and help burn off thinner compounds, such as water and fuel. How would it help burn them off? By keeping them in vapor form so they can pass through the filter media, while the oil condenses and sinks? This is my biggest concern - whether or not vaporized water, fuel, etc. will be sent through the intake to be combusted, or simply condense and get drained back into the crankcase(bad).

Yes, you are correct. Block = good source of convected heat, exhaust manifold = good source of melting your catch can. I'm not saying you want the thing 300*F; you would melt the plastic. But if you put it way off in left field, it will get cold. I think that what you are wanting is perhaps an engineered system, and we are here spitballing on an internet forum. Lacking the actual knowledge and experience of a powertrain management engineer, I think you are going to have to experiment some to get what you are looking for. My gut instinct is to tell you to place a temperature probe in various potential locations in your engine bay and either datalog it or have a passenger watch it as you drive around different places and conditions, and see what looks like it may or may not work. It will never be warm 100% of the time, so knowing what works will still have to come from testing.

Squiddy

Dude, we need to catch up as well. You have PM!