I’m about to take the IM off my 95k S8, to address an oil leak that I hope is the oil filter housing o rings.
I guess it’s still got it’s original PCV fitted, which to my knowledge is working ok. Can you successfully clean it to ensure it works properly, if so how?
Or do you just replace it?, I have also seen some posts on other forums to stick with the OE part when replaceing vs the cheaper Vaico part.
Any thoughts?
Since the PCV is tied to the oil seperator as they are two in one some opt to just replace. We have seen no issues with the many aftermarket options.
Testing is easy you can remove the unit and suck/blow on the low pressure side to make sure the slide puck and spring are working. Since most are not fond of the idea of sucking on trace amounts of oil vapor you can also just pop off the flat large round cover and inspect the spring and diaphram. That is the fail point if your going to find one. 9 out of 10 times if you have an issue with the oil seperator/ pcv unit that diaphram is got a hole or rip in it.
Just take your time when pulling the top cap off it comes off but its snapped on with a good interference fit. There are several good low priced replacement options out there that most opt for just as a maintenance choice thus bypassing testing all together.
Another thing to do if your pulling your intake off. Is get new injectors or look at the JHM rebuilt flowed and matched injectors. JHM is the only company that tests flows the injectors over 1500psi. You can go with standard cleaning but its a much lower psi. Injectors are a must change. Its not if they will go bad but how bad they are now