Wondering what a catch can can catch ?

[V3nn3tj3]

Hey all,

Wondering what a catch can really does and how much better it is to have one?

Here is my rudimental setup atm, still need to make brackets for the hose and make the breather go under the car because of the smell.
Also good to note is that i did a compleet rebuild of the rocker cover. There cover has been torn apart and put back together without and valves, springs, etc. It always breaths through the front pcv hole.
The back pcv has been closed and a catch can has been fitted. Beware, i never saw anyone using this setup as everyone keeps the pipes to the turbo and inlet manifold.
I do believe this is the only way as the fumes get sucked through the OCC and are never fully condenced while beeing there. This is because of the turbo negative pressure on the OCC.
There are still fumes comming from the breather, looks like water vapour but still has an oily smell to it. This proves my point with the OCC with turbo pcv pipe still beeing connected to the OCC.



And this is what came out of it after 1800 km:

[BenS]

Good post, highlights a less thought-of issue! If you have a THP, you need a catch can!

Would be nice to see other people's catch can setup and what they caught with it, so there is all the information in one place

[Czar]

Hey all,

Wondering what a catch can really does and how much better it is to have one?

Here is my rudimental setup atm, still need to make brackets for the hose and make the breather go under the car because of the smell.
Also good to note is that i did a compleet rebuild of the rocker cover. There cover has been torn apart and put back together without and valves, springs, etc. It always breaths through the front pcv hole.
The back pcv has been closed and a catch can has been fitted. Beware, i never saw anyone using this setup as everyone keeps the pipes to the turbo and inlet manifold.
I do believe this is the only way as the fumes get sucked through the OCC and are never fully condenced while beeing there. This is because of the turbo negative pressure on the OCC.
There are still fumes comming from the breather, looks like water vapour but still has an oily smell to it. This proves my point with the OCC with turbo pcv pipe still beeing connected to the OCC.

[ATTACH=CONFIG]13980[/ATTACH]

And this is what came out of it after 1800 km:

[ATTACH=CONFIG]13981[/ATTACH]
[ATTACH=CONFIG]13982[/ATTACH]

Positive crankcase VTA (vent to atmosphere) from what your saying you've dismantled the camshaft cover, removing the pressure diverter valve, and vacuum control flaps, you've now lost all control of positive pressure suspended oil flow, in a little over 1,100 miles, your catch can has collected that amount of oil, what's not evident is the amount which has passed through the tiny filter !!

The surface area of the filter will very quickly become saturated with oil, rendering its ability to vent effectively, the more surface area of the tiny filter that becomes over saturated from gaseous suspended oil, the quicker the tiny filter will clog up, in turn this will add unwanted pressure back on the positive crankcase pressure, not a good scenario, and the remaining open unclogged surface area of the tiny filter will deposit suspended oil particles in your engine bay, or as your planing to do, vent under your car and drop oil onto the road surface!!

Touching back on the point of lost positive pressurised suspended oil flow control, from vacuum control, you are pushing out more suspended oil from the engine, than had you left the camshaft PCV internals alone, and used a catch can/s with some form of internal baffle or filtration medium, to separate any suspended oil before returning the PCV gaseous vapour to be burnt as it was originally designed, to meet emission legislation.

[Jamie@SPTuning]

Take off the tip and have a look inside compressor housing...
My guess it's dripping wet with oil?

[V3nn3tj3]

Compressor housing? What do you mean?
And czar, the filter was not saturated. There is no pressure beeing created in the occ system, it blows freely. I didn't loose any oil in the engine as there is alot of condentation inside the residu.

[Czar]

Compressor housing? What do you mean?
And czar, the filter was not saturated. There is no pressure beeing created in the occ system, it blows freely. I didn't loose any oil in the engine as there is alot of condentation inside the residu.

You'll see what I mean about the filter as time goes by, however, unless you are prepared to wash the filter every 1000 miles.

You have contradicted yourself, you are saying to the forum, look at my catch can set up, and see just how much a catch can actually catches, your images show X amount of fluid in the glass jar, from viewing you're images, there appears to be quite a lot of oil, not emulsified fluid in the glass jar, it would be of benefit to you and to other forum members to measure the actual oil content for reference.

Then you decide that you're catch can has only caught mainly condensation with little oil content, again a measure of the content would be a good idea, if only for reference.

Has you're catch can actually captured the condensation from the engine, or produced the condensation on its own ?

[V3nn3tj3]

Hi czar, i do appreciate the input and will measure how much i have. Please remember that every user here is trying his best to be helpfull, i'm trying to.

And yes, i will have to keep the filter cleaned every few miles. I don't mind if it keeps the engine from clogging up . I still think it's a good setup and i do want to discuss this.

I don't know how much is condentation, i should have mentioned that i am waiting for the residu to shift and create layers again as it was inside the can itself. But might take a while. Might even have to warm it up a bit.

Verstuurd vanaf mijn ONEPLUS A3003 met Tapatalk

[Barola]

Positive crankcase VTA (vent to atmosphere) from what your saying you've dismantled the camshaft cover, removing the pressure diverter valve, and vacuum control flaps, you've now lost all control of positive pressure suspended oil flow, in a little over 1,100 miles, your catch can has collected that amount of oil, what's not evident is the amount which has passed through the tiny filter !!

The surface area of the filter will very quickly become saturated with oil, rendering its ability to vent effectively, the more surface area of the tiny filter that becomes over saturated from gaseous suspended oil, the quicker the tiny filter will clog up, in turn this will add unwanted pressure back on the positive crankcase pressure, not a good scenario, and the remaining open unclogged surface area of the tiny filter will deposit suspended oil particles in your engine bay, or as your planing to do, vent under your car and drop oil onto the road surface!!

Touching back on the point of lost positive pressurised suspended oil flow control, from vacuum control, you are pushing out more suspended oil from the engine, than had you left the camshaft PCV internals alone, and used a catch can/s with some form of internal baffle or filtration medium, to separate any suspended oil before returning the PCV gaseous vapour to be burnt as it was originally designed, to meet emission legislation.

Czar what is your opinion on blanking/deleting the rear PCV valve after so many years that has been discussed positives and negatives on this matter on so many forums?

Thanking you in advance for sharing your thoughts on the matter.

[Czar]

Czar what is your opinion on blanking/deleting the rear PCV valve after so many years that has been discussed positives and negatives on this matter on so many forums?

Thanking you in advance for sharing your thoughts on the matter.

Well as I started this very ball rolling way back in 2009, whilst those that took up on the official blanking caps I sold word wide, the comments were positive, that said, a few comments I received or read about, reported an increase in positive crankcase pressure, increased oil consumption and occasional engine fluctuation, I explained the very reasons for the negative comments, and the issues some people were experiencing.

What you have to remember or be aware of is, whilst an engine is running, the piston rings rotate, or should I say, they should rotate under normal working conditions, therefore it's not uncommon for the Pistons rings to align in such a manner tha more of the cylinder compression pressure Is lost than normal, hence the increase in positive crankcase pressure, oil consumption and engine fluctuation,

The few that did experience one or all of the mentioned symptoms, were very quick to blame the blanking off of the rear PCV, blanking off the rear PCV simply highlighted an inherent engine issue for the individuals suffering one or all of the symptoms, what happened in reality was, did the individuals with the issues, do any diagnostic basics, compression test, cylinder leakdown test, oil consumption weigh, no they didn't, it's all very well pointing and blaming, without any evidence, or diagnosis, when they the individuals offered no evidence.

Is it ok to blank off the rear PCV, yes, however, if any of the mentioned symptoms occur, my advice is to diagnose the actual issue, not simply point and blame, as the success significantly outweighed the problematic few.

[Barola]

Well as I started this very ball rolling way back in 2009, whilst those that took up on the official blanking caps I sold word wide, the comments were positive, that said, a few comments I received or read about, reported an increase in positive crankcase pressure, increased oil consumption and occasional engine fluctuation, I explained the very reasons for the negative comments, and the issues some people were experiencing.

What you have to remember or be aware of is, whilst an engine is running, the piston rings rotate, or should I say, they should rotate under normal working conditions, therefore it's not uncommon for the Pistons rings to align in such a manner tha more of the cylinder compression pressure Is lost than normal, hence the increase in positive crankcase pressure, oil consumption and engine fluctuation,

The few that did experience one or all of the mentioned symptoms, were very quick to blame the blanking off of the rear PCV, blanking off the rear PCV simply highlighted an inherent engine issue for the individuals suffering one or all of the symptoms, what happened in reality was, did the individuals with the issues, do any diagnostic basics, compression test, cylinder leakdown test, oil consumption weigh, no they didn't, it's all very well pointing and blaming, without any evidence, or diagnosis, when they the individuals offered no evidence.

Is it ok to blank off the rear PCV, yes, however, if any of the mentioned symptoms occur, my advice is to diagnose the actual issue, not simply point and blame, as the success significantly outweighed the problematic few.

Firstly I would like to thank you for sharing your experience and great knowledge on the matter.

I believe that most people that look for PCV delete solution already have certain engine symptoms that you have explained. Which makes me conclude that rear PCV delete can safely be done only on perfectly working THP engine which is not often a case

I deleted rear PCV bur returned everything to stock after only 20 days as I have found a small oil pound in turbo inlet housing and was afraid to have rear PCV plugged afterwards. My engine used around 1L of oil per 1k km and has 64k km on clock. Then I changed the intake valve seals and decarbonized piston rings and intake valves. For last 600km I had no oil consumption but I believe there will be some although much lower than before.
From what I understood is that intake valves carbon build up is mostly created by collapsing intake valve rubber seals. This was the case at my friends car as early as on 50k km. I guess it is due to high engine working temperature and also I am not sure that 5w 30 is appropriate oil for this engine if it consumes it a lot although suggested by the factory. I think 10w 50 in summer (hot countries) and 5w 40 for winter oil gradation is a better option.

Also after reading so many post regarding the OCC effectiveness I came to conclusion that this is just how engine was designed and quality of parts it uses and software ECU solution so the intake valve get clogged although quality OCC is installed. In order to have perfectly running engine without carbon build up in my opinion there should be more often oil changes like 5-6k km, intake valves cleaning and deacarbonising piston head/rings at 20-25k km, new intake rubber seals when needed but could be already at 50k km and etc.

[V3nn3tj3]

Hey all,

A little update. After doing a complete PCV delete i've been reading alot about the subject. Even contacted a few people to get a better knowledge of the pcv system.
The PCV system not only relieves pressure that is build up inside the crankcase but also sucks fumes that are know as blowby out of the engine. These blowby gasses are gasses that leak past the sealing rings of the piston and are essentially exhaust fumes. The consist of water, co2, sulfur dioxide and unburned fuel.
The biggest concern when doing a PCV delete is 'sludge'. This sludge looks like mayonaise and could destroy the engine.
I've done 10k since the PCV delete and had to clean the can several times. The content is mostly water with a bit of oil. One of the clever guys i talked to told me that if the delete was causing problems or was harmfull the way to know is if my oil would be dirty or contain sludge. I did an oil and filter change yesterday and the oil and filter were clean. A second check is to smell the oil and the engine when running and look for a sulfur smell. The smell of a boiled egg, there is no such smell. The catch can does stink of it.
This makes me conclude that the pressure inside the engine is high enough for the fumes to be pushed out fast enough and not have it condense inside the engine. Ofcourse water will vaporise when it is mixed in the oil and when the engine gets hot, no way to know... And i did check the compression of the cylinders to check if my piston rings are still good, which they are. It's almost amazing how much pressure buildup is created inside the engine even with good rings.

Just my 0.02.

Nick

[victoryo]

In this case we are talking about adding a catch can to the front PCV.
But what about adding a catchcan to the rear PCV without blanking of the PCV
without vending to air but keep the loop closed..

[V3nn3tj3]

My setup consists of a rocker cover that has been modified. All valves inside the cover have been deleted and the back pcv has been closed. This means that the cover is always breathing to the catch can.
I think adding a occ to both lines won't make a big diffrence as the vacuum sucks the gasses through the occ to fast for the vapours to condensate.

[victoryo]

So basically you made this setup?

[V3nn3tj3]

Yes and no, on the outside it looks like that but remember that there is a whole system of valves and whatnot inside the rocker cover.
I will explain more about the system when i have some time but what you need to know is that there are two valves that are closed when there is no vacuum on the 2 pcv lines. Which means that this setup without a modified rocker cover will never work.