The Hoedown On Catch-Cans

[ManTech]

more evidence as to how catch cans don't work:

http://forums.vwvortex.com/showthrea...res-Discussion

This is the truth, "the beef" redux was looking for. It's proof that these cans are pure .

I'd bet the EGR system is at play here as well! Remember CC's do not address the exhaust gas recirculation system. Those exhaust gases must also be full of oil.

[CC'ed]

Why would the exhaust gases be full of oil ??? (Maybe only if the engine is burning oil because the PCV system isn't filtering the oil mist out before it gets into the intake stream.)

[ManTech]

Why would the exhaust gases be full of oil ??? (Maybe only if the engine is burning oil because the PCV system isn't filtering the oil mist out before it gets into the intake stream.)

During the initial start up of any car, especially if cold, the combustion is never complete nor efficient. The exhaust gas is always filled with disproportionate amounts of unburned fuel, condensed water vapor, oil from ring blow by, valve guides etc. until things start to warm up and tighten up. This doesn't last very long, approx. 15-25 min. depending on the ambient temperature. This condition, known as the *initial warm up phase*, is what caused the EPA to mandate that exhaust gases be recycled in the first place, thus the need for an EGR Valve and Regulator was born.

Today these EGR systems are controlled by the on board fuel management system. It allows these initial gases that are filled with all kinds of unburned fuels, oils, etc. to be recycled and burned again and again, and again in an effort to reduce emissions. These gases are directly injected into the port side of the induction manifold where they normally combine with the PCV gases before flowing past the intake valves. These heavy vapor particles will adhere to these intake valves where they will convert to carbon deposits later on as the engine reaches it's operating temperature. (Let's not forget the exhaust valves. They too will probably need cleaning because of the drawbacks of the DI design.) This accumulative action will mandate a full carbon and valve cleaning be performed since there is no other mechanism to clean the valves such as in the case of cars with port FI instead of DI.

Therefore, it now appears that catch-cans remove far more water vapor that's generated in the crank case during warm up than they do oil vapor later on in their work day! (See links provided in this thread). It makes sense that if these cans are filled with mostly water and very little oil, and this water is only generated during the warm up phase, then they must really do a piss-ass job of removing the oil vapor during the rest of their day. If these cans were doing a better job, then there would be much more oil than water. The evidence appears to show otherwise. (It's disproportionate)

That means that the oil vapor is still getting to the intake valves even with a CC installed. Add to that the daily recycling of oil latent EGR gases that have no way of being removed from the equation during the initial warm up phase and what are you left with? UGLY ASS INTAKE VALVES that will need a full C&V job no matter what you do.



"HEY DUDE, OWN A 2.0FSi or TSi VW? I HAVE JUST WHAT YOU NEED BRO, A CATCH-CAN!"

. Is this Mike?

[crew219]

Why would the exhaust gases be full of oil ??? (Maybe only if the engine is burning oil because the PCV system isn't filtering the oil mist out before it gets into the intake stream.)

You're forgetting that "carbon deposits" can also be left by gasoline.

Dave

[CC'ed]

The purpose of EGR is not to burn (or reburn) any residual "unburned" stuff (fuel or oil), it is used to introduce an "inert" gas (the exhaust contains very little oxygen), to dilute the mixture, which reduces combustion temperatures, which reduce NOX (nitrogen oxides) in the exhaust. The EGR typically is only enabled AFTER the warm-up cycle, and operates typically only under part-throttle operating conditions.

I believe the valve deposits on DI engines is mostly due to the EGR, which does introduce carbon crap onto the intake valve, but I think the oil mist that gets thru the PCV system adds additional crap that deposits on the valves and ports. I think the TSI engine has less deposits than the FSI engine because VW reduced the amount of EGR, or changed how and when its used.

On the observation about water versus oil ratio of what is found in the a catch can: There is far-more volume of water vapor generated when gasoline is burned, compared to the volume of oil mist that is not completly filtered-out by the stock PCV baffles, oil seperator, and added catch-can. From what I can see, only two of the availible catch-cans have a somewhat effective oil-mist filter, that's the Conceptual Polymer and the ProVent. The typical metal baffles and/or stainless-steel wool, found in most catch-cans, are not an effective filter for oil mist particles. You need a "coalescing filter" which filters particles down to a few microns....

[ManTech]

The purpose of EGR is not to burn (or reburrn) any residual "unburned" stuff (fuel or oil), it is used to introduce an "inert" gas (the exhaust contains very little oxygen), to dilute the mixture, which reduces combustion temperatures, which reduce NOX (nitrogen oxides) in the exhaust. The EGR typically is only enabled AFTER the warm-up cycle, and operates typically only under part-throttle operating conditions.

Correct, but it does as a consequence of its design. My efforts above were not to describe how EGR works, but to show that because of what it does, it contributes to the issue at hand. There are some systems that do initiate EGR during warm-up. I believe VW is one of them. In ether case, it appears that the EGR system is a contributor to the carbon build-up on the intake side. Off topic, you are correct that EGR is a nitrogen oxide (NOx) emissions reduction technique. As stated, it works by recirculating a portion of an engine's exhaust gas back to the engine cylinders. In a gasoline engine, this inert exhaust displaces the amount of combustible matter in the cylinder. But in a diesel engine, the exhaust gas replaces some of the excess oxygen in the pre-combustion mixture. Because NOx forms primarily when a mixture of nitrogen and oxygen is subjected to high temperature, the lower combustion chamber temperatures caused by EGR reduces the amount of NOx the combustion generates. As control systems grew more sophisticated, the impact on engine performance improved but other problems were introduced. In a typical automotive spark-ignited (SI) engine, up to 15 percent of the exhaust gas is routed back to the intake as EGR. The maximum quantity is limited by the requirement of the mixture to sustain a contiguous flame front during the combustion event. But in poorly set up applications, an excessive EGR can cause misfires and partial burns. Although EGR does measurably slow combustion, this can largely be compensated for by advancing spark timing. The impact of EGR on engine efficiency largely depends on the specific engine design, and sometimes leads to a compromise between efficiency and NOx emissions. EGR is typically not employed at high loads because it would reduce peak power output. This is because it reduces the intake charge density. EGR is also omitted at idle (low-speed, zero load) because it would cause unstable combustion, resulting in rough idle. Since the EGR system recirculates a portion of exhaust gases, over time the EGR valve can become clogged with carbon deposits that prevent it from operating properly. So it stands to reason that these same gases will do the same to the intake valves as well in a direct injected engine. Today's modern systems utilizing electronic engine control computers, multiple control inputs, and servo-driven EGR valves typically improve performance/efficiency with virtually no impact on drivability, that is, until the intake system on direct injected cars are choked by carbon deposits.

One fact remains, direct injected cars like ours lack the necessary intake cleaning mechanisms of other designs. In an effort to improve overall mileage, and keep costs down, engineers decided on a design compromise which sacrifices the intake systems of these cars. There is no doubt that EGR systems, by design, only contributes to the problem.

[Made in America]

So what is the solution? Or is there a solution? Is it inevitable that the intake valves will need to be cleaned by 40k miles? Sounds like a giant pain in the arse.

[ViRtUaLheretic]

valves this
valves that

CCs do more than just help with valve cleaning, everybody just suspected CCs to be some kin dof miracle drug that would fix all the problems with our motors.
As I have stated MANY MANY MANY times now, CCs have other benefits like removing the PCV gases from your intake, trbo, T.O.P., IC, TB pipe, TB, Intake Manifold, and combustion chambers.
I am 100% sure that there are still added benefits from having a CC than from NOT having one.

If you dont believe me, then dont FREAKING BUY ONE.
/thread

[CC'ed]

The best solution to the intake valve deposits would be to disable EGR, but that would cause pre-ignition issue. Also, it can't be easily done, as the EGR is accomplished by increasing the overlap of the intake camshaft, opening the intake valves earlier, overlapping when the exhaust valve is open. Changing that would require changing the ECU maps for the variable intake cam timing.

[ManTech]

The best solution to the intake valve deposits would be to disable EGR, but that would cause pre-ignition issue. Also, it can't be easily done, as the EGR is accomplished by increasing the overlap of the intake camshaft, opening the intake valves earlier, overlapping when the exhaust valve is open. Changing that would require changing the ECU maps for the variable intake cam timing.

I suspected this was the type of EGR used on our TSi's especially since I cannot locate any EGR device or valve. But doesn't the TSi share the same Bosch Motronic MED engine management system as the FSi? Check out this Bosch video, and take notice of the EGR system used.

[ManTech]

So what is the solution? Or is there a solution? Is it inevitable that the intake valves will need to be cleaned by 40k miles? Sounds like a giant pain in the arse.

there is none, no there isn't, yes, and you bet it is!

[CC'ed]

I suspected this was the type of EGR used on our TSi's especially since I cannot locate any EGR device or valve. But doesn't the TSi share the same Bosch Motronic MED engine management system as the FSi? Check out this Bosch video, and take notice of the EGR system used.

The Bosch video shows an EGR implemented with a separate EGR valve and passage into the intake manifold. The FSI may be like that, I don't know that engine. The MED engine management can be used in various configurations, MED only indicates the family, or generation of engine controller, not its specific detailed features (such as separate of variable valve-timing implemented EGR). For example, the Audi A4 TSFI has an different configuration of the MED controller, as it also controls the exhaust camshaft timing, which the TSI does not.

[Made in America]

there is none, no there isn't, yes, and you bet it is!

What about this service from BG?

http://www.bgfindashop.com/bgservices/fuelair.htm

[ManTech]

What about this service from BG?

http://www.bgfindashop.com/bgservices/fuelair.htm

I dislike their products. Had this service performed on a Mazda I once had that failed inspection. It ruined two O2 sensors, along with a few temperature sensors. BG refused to fix them. Never trusted treatments as a fix for everything.

In any case this stuff is outdated. it may have helped during the 80's and 90's but not with these new engines.

[BsickPassat]

EGR valves..... there is no EGR valve on the engine.

There is EGR function though via the overlap of the exhaust valve timing and intake valve timing.

[BsickPassat]

What about this service from BG?

http://www.bgfindashop.com/bgservices/fuelair.htm

BG has a different service for gas direct injection

http://www.bgprod.com/news/GDI.html --- no experience with it though

[ManTech]

EGR valves..... there is no EGR valve on the engine.

There is EGR function though via the overlap of the exhaust valve timing and intake valve timing.

Todays EGR is either done through timing overlap or through a servo controlled valve. The Bosch MED control FI system utilizes a servo valve. Do you have written proof that our 2.0TSI's have timing overlap? If so, please post or shut up. Thanks.

[BsickPassat]

Todays EGR is either done through timing overlap or through a servo controlled valve. The Bosch MED control FI system utilizes a servo valve. Do you have written proof that our 2.0TSI's have timing overlap? If so, please post or shut up. Thanks.

Do you?

Go read the self study manual for the engine, Self-Study Program 824803 --- there is no EGR servo valve shown as an actuator in the MED 17.5 system for the engine

and the bentley manual doesn't show a EGR valve either.

[ManTech]

Do you?

Go read the self study manual for the engine, Self-Study Program 824803 --- there is no EGR servo valve shown as an actuator in the MED 17.5 system for the engine

and the bentley manual doesn't show a EGR valve either.

Well the Bosch video is all I have. But I did look at my copy of VAG SSP and you're right, it doesn't show a valve, (mechanical nor electronic) but it also doesn't say if it utilizes a valve timing overlap either.

[CC'ed]

The BOSCH video is a generic technical sales pitch on the MED system, it is not meant to be a specific design description of the VW FSI or TSI applications.

What's the argument ? The TSI, and probably the FSI use valve overlap to acheive EGR.

Another note : Don't take the VW Self-Study Course as the "Bible" either, the TSI one has some mistakes/ommisions, as it was probably written before the final design was settled. The TSI course document shows a breather pipe and check-valve for fresh air into the PCV system, from the pre-turbo intake duct to the valve-cover, which does not actually exist on the TSI.

[steelcurtain]

VWrEdux - thank you thank you! It's about time somebody called this ****ing scam out. And I'm not surprised the most brainwashed people are responding and being defensive against you. You all are a bunch of suckers. Go scope your valves and realize how you got played.

[BsickPassat]

Well the Bosch video is all I have. But I did look at my copy of VAG SSP and you're right, it doesn't show a valve, (mechanical nor electronic) but it also doesn't say if it utilizes a valve timing overlap either.

It implies it in the cam phasing system.

INA Camshaft Adjustment System

The 2.0L TSI engine uses a hydraulic vane cell adjuster on the intake camshaft to affect valve
timing. Only the intake camshaft has variably adjusted timing on this engine. Oil pressure for this
task is provided by the engine oil pump. The variable camshaft adjuster provides an adjustment range of 60° crank angle. The camshaft is locked in the retard position at engine shut-off. This unction is performed by a spring-loaded locking pin. The camshaft is released when the engine oil pressure exceeds 7.25 psi (0.5 bar). The rotor of the vane cell adjuster is welded to the intake camshaft. The 4/3-way central valve required for adjuster control is integrated in the camshaft.

Intake camshaft timing is map-controlled by the engine control module. The goals are to improve engine power, enhance running smoothness, and reduce emissions (through internal exhaust gas recirculation).

[dsm1983]

VWrEdux - thank you thank you! It's about time somebody called this ****ing scam out. And I'm not surprised the most brainwashed people are responding and being defensive against you. You all are a bunch of suckers. Go scope your valves and realize how you got played.

you're like
and i'm like

[VWRedux]

VWrEdux - thank you thank you! It's about time somebody called this ****ing scam out. And I'm not surprised the most brainwashed people are responding and being defensive against you. You all are a bunch of suckers. Go scope your valves and realize how you got played.

Thanks! You're welcome! I was just stating the obvious. I had a can in one of my tuned cars a few years back. Ended up throwing it away in the garbage after I discovered it did nothing. When I was a kid, (17) I rebuilt a 1964 Chevy Corvair Turbo Spyder, (200 hp, water/meth injection, the works). I installed a catch-can from JC Whitney even back then. What a hunk of crap the whole concept is. Sure it helps a little, but the rest is just pure fantasy island .

[VWRedux]

This is the truth, "the beef" redux was looking for. It's proof that these cans are pure .

I'd bet the EGR system is at play here as well! Remember CC's do not address the exhaust gas recirculation system. Those exhaust gases must also be full of oil.

Yes it is mantech... it's the "beef" I was looking for alright. (His post below couldn't be clearer!) I'm not sure about the EGR playing a roll, but maybe All I know is that the guys who push this trash based on false advertising should offer refunds to all those who ask for it.

______________________________

THE "BEEF" THAT PROVES THAT CATCH-CANS ARE

You know of the intake valve issue that plagues our engines. I have some pretty good comparison pictures of what an atmospheric catch can actually does. To my knowledge, there havent been pictures taken of one's car with, and then without, a catch can with a good amount of mileage in between while keeping the same engine mods.

Below is a set of comparison pictures. On the left are my valves from 0 to 50,000 miles without a catch can (I got a catch can at maybe 45k, but the damage had already been done, so I am ignoring this). On the right are my valves from 50,000 to 87780 miles with a BSH atmospheric catch can.

















Note: For 50-80k, there was less carbon on the valves than from 0-50k.
Note: Both scenarios had considerable build up on the walls.

You must remember, the pictures with the catch can only span 38,000 miles instead of 50,000 miles. This means there will be less build up regardless of what modifications are in place to alleviate blow by build-up, so take this into consideration.

Also, please note that since this is an atmospheric catch can, I am assuming it is a perfect catch can; meaning that ALL blow by goes out of the engine and is not consumed. This is in comparison to a recirculating catch can where most, but not all blow by gets filtered. Recirculating systems are not a perfect system and there will be a small amount that goes back in the engine and is consumed. With that being said, I consider this comparison a best case scenario in terms of the least amount of blow by possible.

With that said, this is what I conclude from the comparison pictures:

Catch cans work, but I don't think they work as well as we have been lead to believe. They are effective, but only so much. The pictures show there is still a major carbon issue, and this will NOT magically fix your issues. It may delay when the issues start occurring by a few thousand or even tens of thousands of miles, but who knows.

The catch can did more than I was expecting. I thought the catch can would have done next to nothing, but that clearly isn't the case. It did prevent some carbon build up, however much that may be, but the buildup that did collect and the amount of carbon is considerable.

I believe catch cans have a place for the FSI. They work as advertised, albeit less than you are lead to believe, but they work nonetheless. Please take the pictures into consideration when buying a catch can. Remember that they are no magic cure for carbon buildup. That carbon is a tenacious bastard and take up camp on your valves no matter what you do to prevent it.

ANYWAY, enough with the serious **** and here are some pictures from the job















Also, that is what you have to deal with having an atmospheric catch can. It is DIIIIRRRTTTYYYY! I degreased everything and the catch can has been removed. I dont consider it worth the mess for the minimal benefits.

UPDATE: The pics in the post above have been mysteriously lost but they did show the before and after PROOF that catch-cans do very little, if anything, to help the intake port/valves. As Mike later agrees, catch-cans were not designed for this... even though he lists it as a reason to buy his product.... scam.

[BsickPassat]

EGR plays a big role in it.

I know this from back when I had my MKIV TDI, where we have that issue, which VW won't acknowledge. Dialing back on the duty cycle or eliminating it completely basically makes the intake clogging a non-issue.

[crew219]

Yes it is mantech... it's the "beef" I was looking for alright. I'm not sure about the EGR playing a roll, but maybe All I know is that the guys who push this trash based on false advertising should offer refunds to all those who ask for it.

I noticed that BSH pulled the pics of dirty valves off their website. Lol!

[ManTech]

I noticed that BSH pulled the pics of dirty valves off their website. Lol!

I wonder if that means what I think it does?

[steelcurtain]

you're like
and i'm like

Not mad at all. I was laughing thru the whole read! Good info on EGR too and still not a single response from the top 3 sellers of catch cans.

[shawng]

None of them are going to respond to this thread and I don't blame them one bit. No matter what they say, it will end in argument.

[xnox202]

So anyone with the exhaust cut-out on the TSI? If it's possible, I'm going to do it.

[VWRedux]

None of them are going to respond to this thread and I don't blame them one bit. No matter what they say, it will end in argument.

Why would it end-up in an argument? If they have conflicting facts, facts that prove that catch cans actually do postpone or eliminate carbon and valve jobs on 2.0 FSi and TSi engines, I think we would all like to see it! And if this evidence is credible, and contradictory to that which has already been field tested/confirmed and plainly presented (the so-called "beef") by our friends above who posted links to their side by side photo comparison, we would not argue the point with the catch-can manufacturers, we would be joyous and seek further confirmation by duplication.

However I fear they are declining to get involved either because they have nothing to prove their case, or they wish not to do some real work for a change. They rather just sit on their fat butts while milking our wallets. So it's better they not respond because we will press them for evidence to prove that their product is indeed beneficial by SUBSTANTIALLY reducing the carbon build-up inside the intake ports of DI VW's, which will require that they get up off the couch for once.

[HalvieCuw]

None of them are going to respond to this thread and I don't blame them one bit. No matter what they say, it will end in argument.

BSH responded to the thread where those pictures originated from on golfmkv. Said the CC was more for keeping oil out of intake/charge/fmic pipes than reducing buildup. The amount of oil I had in my pipes is enough for me to finally pickup a CC. If that is all it does I guess that is good enough for me.

[Forge US]

None of them are going to respond to this thread and I don't blame them one bit. No matter what they say, it will end in argument.

I'll chime in.

Absolutely nowhere have we ever stated that a catch tank kit, ours specifically, is guaranteed to prevented carbon buildup on your intake valves. If you purchased one of our kits under the assumption that the potential for carbon buildup was going to be completely eliminated immediately upon installation, either someone else led you to believe that, or you came to that conclusion on your own, because no one here would ever had stated as much to anyone.

While we do advertise them as eliminating the return of oil, fuel, and water vapors to the intake tract, as well as LIMITING the potential for intake valve deposits, we do NOT claim that our product eliminates the deposits completely.

It is a known fact that leaking valve guides are another contributing factor that can lead to valve deposits as well, and that potential issue has not yet been addressed by the OEM or aftermarket to our knowledge, so it cannot be overlooked.

We have never guaranteed specific results that anyone can expect from the installation of a catch tank, so to demand that we substantiate claims that have never been made is simply not going to fly. We developed a product that we would use on our own vehicles, and do for that matter, and that we saw a need and a demand for within the market, so we have fulfilled that niche, as others have as well, and the products appear to be performing as intended.

[ManTech]

I'll chime in.

While we do advertise them as eliminating the return of oil, fuel, and water vapors to the intake tract, as well as LIMITING the potential for intake valve deposits, we do NOT claim that our product eliminates the deposits completely.

It is a known fact that leaking valve guides are another contributing factor that can lead to valve deposits as well, and that potential issue has not yet been addressed by the OEM or aftermarket to our knowledge, so it cannot be overlooked.

Well thanks for setting the record straight but that's not exactly how I remember it. Every catch-can thread on vortex to mkv and vi etc was filled with references to the carbon issue as the number one concern by potential customers. And every vendor responded that catch cans do "eliminate all" pcv vented oil. A misleading response in my opinion.*

And so here again you make the same claim that your catch-can "eliminates the return oil", do you not?

So do you have any evidence to back up that claim? How do you know this? Can you accurately measure the amount of oil, fuel and water etc venting from the system at all times and the proportions captured by the catch-can vs that which gets by? If you do, please provide it because all factual evidence says they do not. In fact the above evidence proves that much more is bypassing the can than you realize. *Simply implying that your product eliminates the return oil, and let there be no mistake, the word *eliminates* means all oil, may lead your potential customers into believing that your product will significantly help reduce carbon build-up, when in fact it does not. Plus your theory that carbon build up within the intake port is caused by leaking valve guides is also unsubstantiated because valve guide leakage is at worst almost negligible in a brand new engine.

All fingers point to vendors like you who have taken advantage of those who may not understand your job here.