This is just a guess but I think they are probably not needed as much. This is because biodiesel users report relatively clean intakes. There will probably be some buildup but my guess is not as much which will be normal.
I don't like CCV at all nor PVC on gassers. Why you ask? because the moist oily mist really doesn't need to be re-introduced to the combustion end of the engine.
I worry about some scenario where the oil foams up and gets blown out of the CCV into the intake and you wind up with a runaway. I don't like the idea that oil gets to run down and pool in the intercooler.
With the TDI engine with it's constant pressure being introduced from the exhaust port of the vacuum pump it needs to have an unrestricted way to get rid of that pressure as well as any evaporated moisture from combustion blowby.
I'd much rather see that mixture of air and moisture and oil mist go outside the engine and be released into the atmosphere.
I want my engine to breathe clean, cool, unadulterated air. Disabling the EGR and CCV are two steps I've employed to do that.
The EGR is disabled with a plug in the vacuum line until I get around to purchasing a VCDS cable and set the EGR duty cycle down as low as I can. I'll then hook the vacuum hose back up since it won't be doing anything.
At the moment it throws a check-engine light every so often P0401 if I remember correctly and I just clear it with my scangauge.
The CCV is another beast entirely, there are threads on this forum describing ways of de-oiling and de-watering the CCV output and then re-introducing it back into the intake pre-turbo.
For now I got a small filter from autozone that looks similar to the following:
I drilled out the rubber to increase the diameter of the input and it fits very tightly into the rubber grommet that the CCV puck fits into. I took off the puck and put that in my spare parts box and used a stopper around the right size and blocked the input tube that would have connected to the other port on the puck.
The gauze was blue when I started, now it is dark blue so the oil is having some effect on it. It hasn't started weeping or making a mess so perhaps the oil that solidifies inside it drips back down into the cam cover.
It remains to be seen how it behaves in the winter but I don't think I will have any issues with freezing moisture.
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