For over a year I have not been able to figure out why I am getting such high KR counts and why the past two dyno's have been down. While swapping out the elbow on my CAI yesterday I noticed that again the ECU was coated in oil from my BOV (again). I have a check valve and just assumed the PCV was bad. So I get a bug up my ass this morning on how to solve this and decide screw it I'm going the $20 catch can route. So I pull a few articles up on how to build one and I come across an article that the crankcase wants to have vacuum at idle through WOT. I was running a breather on the driver side nipple and didn't think anything of it. Turns out that the turbo provies the vacuum via the intake under WOT conditions. The oil from the excessive blow by was causing the computer to pull timing since it thought it was running with a lower octance fuel. Aparently it also sludges up the tops of the pistons and valves so I will sneak a peak next plug change. So I buy two and run a catch can between the throttle body and the pcv and I run another from the valve cover to the CAI. I take it out for a spin and some data logging and sure as shit the KR is pinned at 0 till the last little bit before redline (which makes sense since the turbo is moving to the inefficient portion of the pressure curve). Before when I hit peak boost I would have at a minimum a count of 3 KR moving up towards 5 or 6 as I closed in on redline. For a year I have been chasing down causes, boost leaks, faulty sensors, bad wires, bad coils, bad gas, bad injectors. Kind of ironic that 50 bucks and lowes fixed the problem. So if you are using a breather stop and save yourself the trouble.
nate....i thought you knew better....the dsm guys figured that one out 8 years ago...get with the program buddy i had the same issue, but i was running a CC on the PCV>Crankcase side and a breather on the Crankcase>Intake side. i routed the Crankcase>Intake side back to the intake with no CC and it solved the problem. the reason i changed was because of an article on dsm tuners from the year 2000....hahah but this was back in '05 mind you
Lulz.....I noticed a drop in performance when I put a breather on my neon years ago. As soon as I put that little two inch hose back on, I could tell instantly. I would have told you this a long time ago if I knew....
As sad as it is to admit this I even spaced the breather myself. I was so busy chasing other "problems" that I just kinda wrote it off for the time being didn't get back around to it till now. Its one of the reasons why I made this thread so down the road if someone searches for KR problems they will find this.
also having the driver side nipple to vac also helps seals the rings and seals by pilling a vac in the crankcase
A breather would probably work if you put a check valve under it right? So the intake side is only intake? The PCV valve should be one way and prevent you from building pressure in the crank case. or you could put a check valve on that side to0 so it's out only? but I suppose vacuum all the time in the crank case is better.
From what I understand no because you are still venting to atmosphere it needs to see vacuum to draw out the pressure from the crankcase.
The issue is blow by and the pcv while in boost there's pressure coming from both and just a vent really isn't good enough
Glad that fixed your KR issue... interesting findings! Glad you posted this, that way whenever someone argues with me about its okay to run a breather there I will point them to this thread.
