Regarding VG30ET.

In the beginning, I was getting oil on the PCV valve. Also, I had the left side vented with a filter and it was getting saturated and leaking down onto my exhaust manifolds. Under boost, my dip stick would blow out as well. *Of course I can't tell if it's under boost or when I let off the throttle during boost?

I've had this issue since firing up the engine the first time and boosting. I added two oil catch cans: one to the left valve cover and running it to the preturbo for suction. The second runs between the right valve cover and the PCV valve. With these cans, I have seen very little oil accumulation, I would dare say a few drops in the left side can. So, that addresses the first issue about eliminating oil back into the intake and facilitates crank case ventilation.

Now, I had originally thought that these cans would take care of the oil dip stick blowing out. It helped, as I've not experienced it coming almost completely out of the shaft. However, it still creeps up enough to get oil on the A/C, valve cover, and other surrounding parts. Outside of strapping the dipstick down with a tie, is there some way of securing the dipstick? Does Nismo make one that might screw into the shaft or fit tighter. My dipstick is really loose fitting. Well, I guess as loose as any other VG I've messed with. Any/All help is greatly appreciated!

 

Roll some electrical tape around the end of yours.

DF

 

Well... If your setups right.. you wont blow the dipstick out.. so something is still wrong. Is there anyway that boost could leak into the crankcase? anyway at all..? if no boost can leak into the crankcase.. then how much air can vent out of the crankcase... If thats not a problem.. then... id dare say its because of blow by.. I had my dipstick blow out once... I had lots of ventalation and no way boost could enter.. and it tuned out being broken ring lands... First thing i would do is at idle is route all of the vent tubes except the pcv, leave that hooked up.. into a plastic shopping bag.... and kinda seal it with your hands.. if the bag inflates real fast ... its blow by.. if it just kinda pulses and slowly fills your fine, and if it slowly shrinks your great. Just something to start with..

Jeremy

 

I've identified a kinked hose between the PCV and catch can on right side. I've shortened hose. I am going to check the lines on the left side vent. I've got it run from valve cover to oil can to intake (preturbo). However, this area of the intake is really short and the vent line from the engine is between the turbo and where the Bypass valve re-enters the intake system. I'll utilize your "bag" test to see if I may be creating any positive pressure in that line, shouldn't, but need to check flow to rule everything out. Thanks for the input. Everything on the engine is new, I hate to imagine that something is "bad" as you mentioned, but I know it does happen. BTW, I do experience smoke between boosted shifts. It's a "puff" but, I can see it in my rear view.

 

I would suggest the following:

Enlarge PCV passage (or make new ones on BOTH valve covers and close the factory PCV tube). Run a hose to a catch can. You can find one here...

http://item.express.ebay.com/_Car-Tr...mdZExpressItem

I would put a breather/filter on the top. All of your crankcase vapor would go in the can (including oil vapor). You could then periodically drain the oil into a can/bottle and put the oil back in the engine.

HTH's

 

Jay: Are you saying that by doing away with the PCV, that this may resolve some smoke during shifting....that I may still be pulling some oil into the intake manifold? I already have two cans though, one for each side. I got mine off ebay for $15 each. However, I'm not sure how venting to air is better than utilizing the PCV or intake (pre-turbo) to pull vacuum on the valve cover and crank case? I had understood that vacuum in the crank case is preferred? I had actaully thought about installing an electronic vacuum pump. Pricey!

 

You can actually gain a bit of power putting a good vacuum on the crankcase. You definitely do not want any pressure though and you don't really want one hooked to the intake and others vented as this will literally cause a vacuum and boost leak.

 

Thanks Cookson for confirming this. I've heard from others that they have lost boost pressure by venting and is why I've got everything set up (supposedly) to vacuum. I still need to verify if I'm geting any vacuum from my intake. Since it is so short and I have a cone filter, I may not be pulling any on the lines connected to it (again, pre-turbo). There is no doubt though that there is a crap load of suction off the manifold, feels like it wants to suck my finger through the PCV valve!

However, Cookson....by what you say, if I run the left vent back into the intake (pre-turbo), how am I loosing boost? It's being recycled right back into the turbo? But, if that is true, then outside of a vacuum pump, there is no way to avoid some boost loss, is that right? What other way is there to run our crank case ventalation? How does the "swapping" of ventalation (PCV versus intake) affect this seemingly inherent loss of boost pressure? I'm referring to fact that at idle, engine vents through PCV and at acceleration/throttle it vents through intake system?

 

Running it before the compressor should be better than venting to atmosphere. The biggest key here is that the air is metered so it would essentially be like venting the blow off valve to the atmosphere, just not as extreme.

I don't know much about these but you may check the Krank Vents out. To me they just seem like high quality PCV valves but they do have a setup for turbo systems that allows crank case vacuum while keeping boost out. http://www.et-performance.com/turbo.html

 

Great find. I'll look into it further. I have a new PCV valve, but it may simply be crapping out. I'm not pushing a lot of boost, but it is an AutoZone valve for the Max, not even intended for use in a boosted application. Thanks!

 

Hey...

Maybe I didnt read all the way through the post...

How is your PCV system hooked up?

If your car is blowing the dipstick out, you might have blowby OR faulty PCV valve. I personally would run a check valve instead of the PCV valve but if you have blow-by, the check valve wont help. It will still blow crankcase pressure out of the PCV line ahead of the turbo and you will have oil in your intake before the turbo. And if the crankcase cant vent fast enough, you will keep blowing the dipstick out. You can also push oil past your seals AND gaskets.

I could personally give a you-know-what about PCV. Someone stated that you may cause a vacuum leak with a catch can. Sure you can, if the PCV is still hooked up. That will cause a MAJOR vacuum leak! Your MAF sensor wont read all of the air going into the engine. The ECM will go NUTS. Get rid of the PCV and run the catch cans off of the valve covers ONLY. When you get into boost and IF there is blow-by, the pressure will vent into the catch cans and out of the breathers. The oil vapor will collect in the cans. You will have less chance of blowing the dipstick out.

If you have dont have excessive blow-by, try the check-valve approach. If you have a LOT of blow-by, use the catch cans and forget about the PCV system.

I wonder if anyone makes a closed-loop catch can. Where you have big enough lines to vent the crankcase properly and still have the benefits of the PCV system. This will require a line to get filtered air before the turbo, 2 large lines from the valve covers, a check-valved line from the intake manifold to the crankcase, and a catch can with 3 ports (one port on top, two baffled ports on the side)

Sounds complicated huh? I think I just confused myself!

 

Take a look at this thread over at LS1TECH...

http://ls1tech.com/forums/showthread...&highlight=pcv

 

I've done my testing guys. I have great vacuum off the right side valve cover from the PCV valve. I simply can't test vacuum/pressure off this line under driving conditions/boosting. I also verified that I am getting a small vacuum off the intake when throttled. However, vacuum off the intake (pre-turbo) is minimal, pulled air out of a bag, but nothing substantial and was slow. Can't feel it with my finger. I'm wondering if my lines are not too small. I'm talking inner diameter about that of a pencil. I'll look at enlarging them, see if I pull any greater vacuum off the intake from the larger lines.

Here is what I get from that link. A vacuum pump is for serious horsepower. I don't think that I'm pushing anywhere near what may require a vacuum pump (though is still an option just to resolve my issue). I've already tried running a filter on the left side valve cover, it got oil soaked and leaked down my engine. That is why I added the catch cans.

So, I see that I have a couple of options. 1. Vacuum pump. 2. Eliminate the PCV and run a catch can on both valve covers and vent them to atmosphere. No vacuum though to offset the pressure in the crank case. 3. Eliminate PCV and run both valve covers through a catch can and into the intake system using a larger hose (I can set up one can to pull from both covers and have a third line running to the intake). By the third option, I won't have fresh air coming into the crank case nor will I have vacuum at idle. However, any pressures would be pushed out the system at idle. On the other hand, pressures would be evacuated at a greater rate on this third method, especially at acceleration/boosting when my pressures are clearly greatest and causing me a headache. Also, at vacuum, I'm sure I'd be pulling some fresh air in through the dip stick. Only concern there is that such air would be unmetered. I'll have to look at that aspect.

BTW: I've found some smog pumps on ebay. Would one of these units provide sufficient vacuum for the crank case? Anyone got a good/used electronic smog pump lying around?

 

One of the guys on that link I sent you has his set up like this...

1 line from each valve cover to the 2 ports on the catch can.

1 line from TOP of catch can to CAI (between air filter and turbo, but behind MAF)

1 line from vacuum port on manifold to a valve cover with a check valve (check valve will prevent boost from pressurizing crankcase but will still allow vacuum to evacute crankcase when throttle is closed)

If set up like this, you will have a closed-loop pcv system AND crankcase evacuation when under boost. No more blowing out the dipstick. No more spraying oil all over the place.

Why dont you try this set-up and see how it works.

 

Right now, the biggest barrier is that I don't have a good check valve. That would require utilizing what Cookson suggested. It sounds like all those "T" connections and tapping into everything would be messy. What I think I'm leaning to now is modifying one of my catch cans to enlarge the ports. Then run lines from both valve covers to the can. Run a third line into the intake until I can get a vacuum pump/smog pump. Actually, I may just block off the left valve cover and just pull vacuum off the right side.

 

Update: I've obtained a used vacuum pump off a boy's Chevy. Some start up issues through trying to eliminate the PCV valve. So, I've tried hooking up a vacuum controled check valve that came with the vacuum pump. Still having some start up issues. So, I'll likley just get rid of the check valve and run the PCV line to the intake (pre-turbo but after the MAF. I'll have to monitor and see how much boost loss I experience until I can better resolve my startup and idle issues by eliminating the PCV valve. Attempts to adjust the IACV were unsuccessful.