[Dave92N54]

Looks about right i'd guess, maybe a little more than expected. The oil isn't the main cause of the build up, it's mostly from combustion.

[Serf27]

Combustion?
That happens under the valves?
Small traces of oil in the system due to the catch cans not working properly I’m assuming.
The PCV delete fitting uses an o ring to block the head passages.

[JonEQuest]

Originally Posted by Serf27

I had to pull my intake manifold off to replace the starter. I took a look at the valves and they look as if there isn’t any catch can in place or as if the pcv delete (which blocks off the passage to the head ports) is not working.
My catch cans are still catching oil, but the valves looked dirty and there was a trace amounts of oil in the charge pipe/throttle body.

Now these valves, I cleaned very well last year. I didn’t Keep track of the mileage, but I’d say this is about 10-15k worth of miles.


What gives?

I actually just changed my starter 2 days ago and my valves look identical to yours. The catch cans must help because both are catching oil but i do see some oil residue in the BOV and the intake so although we eliminated (or at least reduced) the PCV sending oil back into the cylinders with OCC and blocking the 6 ports it seem the main cause is oil seeping by the turbos. Maybe that is because I have 17T's, some may say it is because mine are Wuhan Warriors, but I am sure ALL snails running higher boost are going to seep SOME oil. The invention that would sell lie hotcakes would be a magic oil separator between turbos and the intake that somehow doesn't reduce flow. I have come to the conclusion that 99% of these cars are driving around with dirty intake valves and they are running fine. I would rather have a way to keep them clean but the only thing I can think of that would work great would be port injection. That would literally wash fuel over the intake valves often enough to "clean" them as well. If I keep adding power a port injection system would probably be my next step anyway. I also thought about taking a spare intake I have and adding port nipples to it, but capping them for now. Not only to add port injection later, but you could also take off the caps one at a time and spray some injector cleaner in them occasionally to clean the intake valves.
Any thoughts from the peanut gallery???

[Serf27]

It must be the turbos. My turbos are stock but the boost is up there.

If we are gathering this much build up with a system in place in such a short amount of time, other valves must be really caked up.

I agree, not every n54 has a CC system, especially stock ones and they run fine. It would be nice to just have clean valves.

I don’t think a few squirts of cleaner would clean the valves at this point. Maybe if you spray them down every other drive.

The only thing I can think of is just cleaning them once a year and not letting the build up accumulate over time.

[mweisdorfer]

Originally Posted by Serf27

It’s my understanding the RB PCV is a stock replacement and doesn’t block the passages in the cylinder head?

I’m doing a valve cleaning this week and would like to block the passages on the head to keep the valves clean.

I already have the RB replacement valve and 1 generic N54 oil catch can.

You have to be careful with "generic" catch cans. Not all catch cans are created equal. The filters they have is what determines whether they should go in the high or low side.

[Serf27]

Originally Posted by mweisdorfer

You have to be careful with "generic" catch cans. Not all catch cans are created equal. The filters they have is what determines whether they should go in the high or low side.

This is the first I’m hearing of this.
This is the catch can I was referring to.

https://www.ebay.com/itm/Billet-Alum...-127632-2357-0

[mweisdorfer]

Originally Posted by Serf27

This is the first I'm hearing of this.
This is the catch can I was referring to.

https://www.ebay.com/itm/Billet-Alum...-127632-2357-0

Idk anything about this catch can. The Mishimoto catch can has a very fine filter & the BMS catch can does not, which makes them perfect for placing them on the high & low sides of the PCV system.

[Dave92N54]

Originally Posted by Serf27

Combustion?
That happens under the valves?
Small traces of oil in the system due to the catch cans not working properly I’m assuming.
The PCV delete fitting uses an o ring to block the head passages.

Yes. Obviously the oil plays a part, i'm not saying it doesn't, but you could remove every last bit of oil that hits those valves and you'll still need to clean them every 50-60k.