So I'm not entirely clued up on the S3 2.0TFSI engine and heard various things concerning the front PCV on the car and some common faults with it. I was wondering if anyone could explain the pro's and con's of changing it to a blocked off one or switch to a catch can system?
PCV Questions, block it off, catch can?
- Thread starter isimpoi
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If you simply block it off,there will be issues with either raised pressures in the cam cover,or venting oil vapour elsewhere,usually out of the rear breathers,which dump into the turbo inlet.
A catch can will,as it's name suggests,catch some of the vapour from the cam cover,but as there are 2 breathers at the rear of the cam cover,it won't catch it all.
What eventually happens is that some of the muck builds up on the inlet valve stems,and they look like this....
When you have them walnut blasted,they look like this again,for a while.....
In time they will look like the first again....
The only real solution is a vent to atmosphere system like this.....
But this is costly,as it requires a billet cam cover,plus the breather system,and it needs to be emptied pretty often....
There is no one easy answer unfortunately.
A catch can will,as it's name suggests,catch some of the vapour from the cam cover,but as there are 2 breathers at the rear of the cam cover,it won't catch it all.
What eventually happens is that some of the muck builds up on the inlet valve stems,and they look like this....
When you have them walnut blasted,they look like this again,for a while.....
In time they will look like the first again....
The only real solution is a vent to atmosphere system like this.....
But this is costly,as it requires a billet cam cover,plus the breather system,and it needs to be emptied pretty often....
There is no one easy answer unfortunately.
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I was under the impression that for Stage 2 and below having a catch can is a little pointless......nice to look at but very little oil vapour being produced. Would be nice to know whether or not this is gen as I know for Stage 1 it isnt really worthwhile. Your opinion please S3Alex if you may.......lol
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I think it's a pretty good question.....
I know that on all the occasions that mine has been stripped down prior to the setup I've got now,the valve stems have looked pretty nasty.
To be fair,that's only been done at Stg2+ or above,so I can't really comment on it much below that level.
The only other evidence is from everyone who's already got a catch can,and pretty much everyone finds it fills with muck at anywhere from 1-3 months depending on state of tune,and how cold it is etc etc.
I guess the easiest thing to say is that if you're planning at some point to go to Stg2+ or a hybrid/big turbo kit,then it's useful,and worth considering the VTA system I've got if you're looking for a lot of power.
The other solutions are either regular walnut blasting,or the later versions of Terraclean.
Very useful info, thanks Alex. Just curious to what walnut blasting and Terraclean are? Is terraclean like that seafoam stuff you run through your car? Walnut blasting I assume is a case of opening up the engine and blasting away the carbon and a costly job.
By the sounds of things it would be simplier and more cost effective just keeping the standard pcv haha 
but I'll definitely consider using one of those carbon reducing methods and oil change before I go stage 2+ just so I have a fresher engine
but I'll definitely consider using one of those carbon reducing methods and oil change before I go stage 2+ just so I have a fresher engineI had the Pcv delete on for a while but I've just swapped it for a catch can but I've only done about 700 miles with it so not emptied it yet,
Does terra clean work on the s3 alex or is the walnut blasting better ? Mines is at 26000 miles now so was considering one at the end of the year to give it a good clean and get it all serviced and that aswell
I've been doing some research on it and the terraclean does do a good job of removing or at least skimming a good layer of carbon out of the engine and exhaust system and can usually get it done for under £100 where as the Walnut blasting it a lot more thorough and gets rid of near all of the carbon build up and costs closer to £250-300 (at least that was the price I seen offered, there may be better deals out there)
I'm going to go for the terraclean before I start remapping and doing major modifications just to clear out some of the build up and have a smoother running engine. Also since there is a place very close by that offers it at £75 which is pretty good price compared to other places I've looked.
I'm going to go for the terraclean before I start remapping and doing major modifications just to clear out some of the build up and have a smoother running engine. Also since there is a place very close by that offers it at £75 which is pretty good price compared to other places I've looked.
Compkiler
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Interesting. Just been quoted 108 quid for the terraclean and he comes to my house aswell, and for a few quid more he will go in from the top and clean from above too. Sounds good to me to keep the engine running smoothly!
I'll book mine in next time I'm up for a service!
I'll book mine in next time I'm up for a service!
Sounds like a really good service that, especially if its mobile and comes to your house
ckl139
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If you simply block it off,there will be issues with either raised pressures in the cam cover,or venting oil vapour elsewhere,usually out of the rear breathers,which dump into the turbo inlet.
A catch can will,as it's name suggests,catch some of the vapour from the cam cover,but as there are 2 breathers at the rear of the cam cover,it won't catch it all.
What eventually happens is that some of the muck builds up on the inlet valve stems,and they look like this....
When you have them walnut blasted,they look like this again,for a while.....
In time they will look like the first again....
The only real solution is a vent to atmosphere system like this.....
But this is costly,as it requires a billet cam cover,plus the breather system,and it needs to be emptied pretty often....
There is no one easy answer unfortunately.
Hi can you post pictures in another format as these aren't viewable
