No boost and pcv question

[redcamaro1996]

Hey guys,

So I'm currently in the process of working out the kinks of a remote turbo build. I know many aren't a fan of this set up to begin with for various reasons, but I decided to go for it due to the the previous mods I have done.

I thought I had a boost leak somewhere in the charge pipe, so I tried to test for the leak by running compressed air though the charge pipe with the engine off and turbo inlet blocked. The throttle plate was closed during this test. I had 3 psi in the charge pipe during the test (tee'd my boost gauge in so I would know if it was holding pressure). After going through the entire charge pipe I found no leaks, but that lots (bassically all) the pressure was coming out through the valve cover breather.

Is this normal for when the engine isn't running?

I realize there have been similar conversations about this on the forum usually relating to PCV bypass. I would prefer not to rehash the breather vs drilling throttle body argument, but just for your reference I blocked the tb with a set screw. Also its a 96 with angled tb.

Am I missing something here? You FI guys aren't modifying or removing your PCV valves to make this work are you?

What about the other gaping hole in the tb before the throtte plate? It looks like it leads to the iac? This doesn't lead to the crankcase does it?

Ultimately I'm just confused why the pressure seems to be going through the crankcase despite having the tb plug. Any help is greatly appreciated.

[redcamaro1996]

Re: No boost and pcv question

The more research I do the more I'm worrying about bad rings. Anyone have experience with blown piston rings? The car is running good as ever, no indication of missing. What would ring problems sound like?

[MegaHertz]

Re: No boost and pcv question

Have you done a compression test if you suspect the rings? I've seen many threads talking about modding the PCV system for forced induction. I've not retained enough of it to offer advice but here is one thread I've read:
http://forum.camarov6.com/showthread.php?t=103164

[ssms5411]

Re: No boost and pcv question

Aslong as you PCV is blocked you shouldn't have blow by ,except like stated piston rings air is suppose to move out the breather ,if it didn't your dip stick would blow out with oil every where.

[techsan23]

Re: No boost and pcv question

I cant remember the exact size, but I used about a 3/8" plug, and threaded it into the back of the throttle body in the pcv passage. But you used a set screw? Have you pulled the main intake pipe off the throttle body, put your hand over the end and tried revving it up with the throttle linkage to see if the turbo is building boost?

[ssms5411]

Re: No boost and pcv question

Yes, its a 3/8th plug in the back of the TB works great.

[redcamaro1996]

Re: No boost and pcv question

I'm doing the compression test as we speak. Will post those results later, presumably it will not be good. I think by plug and set screw we mean the same thing. I used a 3/8 tap in the back of the throttle body and screwed in a plug with rtv. I used a vacuum tester to verify that the plug was not leaking.

[ssms5411]

Re: No boost and pcv question

Sounds like you did the TB right , so there has to be a problem somewhere, maybe your wasgate is stuck open.

[redcamaro1996]

Re: No boost and pcv question

Compression test complete. No abnormally low cylinders. All tested between 200-210. This doesn't seem consistent with ring issues? Also there is no smoke to indicate an oil ring.

It isn't the BOV. I actually removed it (Replaced it with solid pipe) when I was pressurizing the charge pipe with compressed air to remove that variable. The charge pipe held 3 psi and I didn't hear/feel/see with soapy water any leaks in the charge pipe. All of the pressure was coming out through the valve cover vent.

When reading other posts I see a lot of PCV block off and ring issues being brought up for this problem. What about intake gasket though? It looks like a crack in the LIM to head gasket could theoretically cause this same issue, thoughts?

[ssms5411]

Re: No boost and pcv question

I would check your wastegate.

[redcamaro1996]

Re: No boost and pcv question

Does it seem strange that using 5psi of compressed air and a vacuum tester on both ends of the PCV valve doesn't create a seal? Does this sound like a cleaning/replacement is in order? Shouldn't it check one direction or the other? The air flows through freely in both ways.

[ssms5411]

Re: No boost and pcv question

If your TB is plugged you shouldn't have any air going through.

[Unique96Camaro]

Re: No boost and pcv question

If your TB is plugged you shouldn't have any air going through.

You did the egr mod right?

[redcamaro1996]

Re: No boost and pcv question

You did the egr mod right?

I have block off plates at the egr and plenum. Is this sufficient?

[redcamaro1996]

Re: No boost and pcv question

So after putting new NGK TR6s in and replacing the PCV valve I did some more intake pressure tests.

1.) verified that blowing compressed air through the hole in the tb before the throttle plate does not pressurize anything. It is adequately blocked.

2.) When I removed the PCV valve I noticed a small hole in the intake manifold, I assumed this would lead to the hole that I should have blocked off. When the intake was pressurized pressure still comes out this hole. Am I the first to notice this? Is this something unique to my system? This has to mean there is some other path from the PCV intake hole to the intake other than the tb hole.

3.) If anyone is interested enough I would love to know if a similar thing happens to someone else with tb pcv mod done. If this is in fact true (*controversy alert) then the tb plug method isn't sufficient for FI? There is another pathway to the intake somewhere. Not trying to ruffle any feathers but this seems to be true for my current set up.

Thanks for all the responses so far.

Has anyone run this set up with no PCV valve?