[Rufflesj]

I bought a similar one, then researched it and sent it back..... error on my part.... I came to the conclusion that the pcv system is there for a reason and not to mess with it by blanking it off

What's bad about them?

 

[Rufflesj]

Your factory PCV valve is designed to remove excessive crankcase pressure (byproduct of combustion gases slipping past your piston rings) without contaminating the environment. If not removed, excessive crankcase pressure will lead to crankcase seal damage and / or oil leaks

The PCV accomplishes this with a couple of check valves that route the waste gasses in a couple different directions
One path uses engine vacuum during idle / cruise to direct that waste back into your intake tract, the other routes the waste back to your turbo during boost. In either case the waste byproducts are burnt-off during combustion, reducing them to less harmful CO2 & H2O.

With a PCV delete your engine will only scavenge / extract crankcase blowby during boost since you've blocked the path used during vacuum / idle. This leads to dirty oil (oil fouled quicker due to the additional combustion byproducts that would have otherwise been burnt-off).

PCV valves are cheap & easy to replace when they fail. No real benefit to installing a PCV delete on a street car.

I see, cheers for the info.

 

[Rufflesj]

I've had it on for 18 months (7K miles) without any issues whatsoever. I put it on while sorting a vacuum leak caused by the PCV and under the advice of my trusted Audi (&TT) specialist. Since then, I've run an oil sample test and the car was MOTd. Emission results are better now than before the mod and there's been no increase in the level of soot as per the oil sample test.

This very same one mate?

 

[Rufflesj]

Looks same as every other PCV 'delete' on the market
This style delete doesn't achieve any benefit for the engine - just the likelyhood of increasing crankcase pressure.
FNChoas explained it perfectly, which explains why the most common fault seen fitting these on is increased smoking off boost.

OE PCV has it's own flaws, but is a pretty decent set up and works well enough when in good condition - just about keeping it that way!

The only replacement which would benefit would be a properly delete, where the lower breath line from the oil seperator on top of the filter housing & the breather from rear of the rocker hose are plumbed with large diameter tubing to atmosphere - which doesn't increase crank case pressure like catch cans etc
But this isn't idle on road car for possible legal reasons

I see, thought this was slightly different as catch cans aren't mentioned. I'll leave well alone so!