New to forum, 2015 JKU with 3.5 AEV, Prodigy Stage 2

[Bkeef]

Check valve wasn't closing properly. It had a rough movement. We have another one coming just for backup.

Even with the repaired check valve we are still blowing the oil on part load driving. We could not determine any leaks thoughout the PCV system. I didn't ask if my guy smoke tested it but he says it's right now. What's strange is under full hauling ass driving there is almost no oil coming out. I really notice it on highway driving cruising 2200/3000 rpm when the boost comes in and out. This made us believe this was PCV related. You may be right about the repair fixed a small vacuum leak. The catch can sure as hell fixes the oil issue. Check valve was installed correctly originally so it wasn't backards. What I'm curious if the spring is weakened more will it bring on boost quicker?

I can only hope there is no other underlying issue. It sure drives great now so who knows.

** note to googlers. Must add catch can to Moroso 84565 search unless your into Asian porn.

Pickles, Dan caught this before you when I was telling him about the mod. LOl

[UselessPickles]

Check valve wasn't closing properly.

That makes sense. If it wasn't *closing* properly, then it would allow boost to blow through the crankcase and out the breather. This would also essentially behave like a boost leak, causing boost to take longer and require higher rpms to build up. Sounds like that was the root problem.

What I'm curious if the spring is weakened more will it bring on boost quicker?

No. The spring holds the check valve closed, and a closed check valve is what is necessary to avoid a boost leak into the crankcase. Weakening the spring would make it open more easily, which may allow the PCV system to operate more efficiently at part throttle cruising, but would have no effect on performance at higher engine loads... unless it is weakened so much that it doesn't reliably close, and that would bring you back to the same problem you just solved.



One attribute of check valves is "cracking pressure"... the amount of pressure required to "crack" the valve open. The best option for this application would be a zero cracking pressure valve. It would basically behave as if it didn't exist at all any time there was no boost, and the PCV system would work exactly as originally designed. As soon as manifold pressure crossed into the positive boost range, the valve would close and prevent boost from entering the crank case.

The check valve in the turbo kit seems to require quite a bit of pressure to crack it open. That means that at certain engine loads when the stock PCV valve would normally allow manifold vacuum to suck some air from the crankcase, the check valve is actually staying closed and preventing airflow through the crankcase. I'm thinking of replacing it with a valve that has a low cracking pressure (0.3 psi). That's the lowest cracking pressure I was able to find for a check valve that is the right size, etc. Dan at Prodigy was not able to obtain the specs for the check valve they use, so I'm not even certain that my replacement would be an improvement.