3 Z06ZR1

Interesting they changed the PVC line on the 2014 Z51 from going from the dry sump straight to the intake.

On the Z06 it divides and goes to the Valve cover like a vender here came up with. My 2015 is burning clean exhaust tips!

slesher

Had this change done on my 2014 Z51. Smart mods ftw

567Chev

I thought on my 2014 Z51, the line runs from intake tube to the dry sump tank, then runs from the dry sump tank and splits, joining the valve cover on the passenger side in two spots - half way along the cover and at the front. My car is in shop so I can't check.

What exactly was the change for 2015? Maybe someone has a pic?

meyerweb

Is this really the PCV, or is it just to prevent any burping from the oil tank from getting into the intake? That's not the same as the combustion blow-by the PCV valve (or a catch can) is designed to deal with.

Higgs Boson

You are correct, the burp line from the dry sump tank is not technically part of the PCV (not PVC as OP says) system but it is part of the oiling system.

RpeterK

This is a mod that is covered in the ECS kit instructions. Having a need to resolve an obvious GM blunder we came up with this to end the burping issue. Funny how they might have gotten word of this simple change or read the forum but I tried to get a hold of the engineer that was in charge of the crankcase venting portion to discuss the simple but effective re route but to no avail. Even tried to see if he was at sema while I was there. Hopefully they will follow through with the rest of the non z06 dry sump cars soon. I could see how they might want to use up a massive run of parts since they already put out the bulletin about the hash marks on dip stick. I spoke with the company that makes the breather lines and even a couple thousand parts doesnt seem to move them. Allot of expensive tooling does go into making these lines. Who knows? Any yes this isnt really a pcv issue but burping oil into the intact tract will sure enough make for a very bad pcv issue.

Higgs Boson

I agree. Hard to believe that as long as cars have been out there are still mistakes like there are. I mean seriously, stop trying to reinvent the wheel or get literally as cheap as possible with the little bs items (like an ignition switch)....

HalfMoon

Can someone point me to this change by GM and ECS?

My google attempts are coming back unrelated.

Thanks.

567Chev

Ditto on more detail on the change. I can't figure out if they're talking about splitting the air bridge from the intake to dry sump tank or some other change.

Higgs Boson

It sounds like he is saying they changed the dry sump tank vent line from the intake (Z51) to the valve cover (Z06).

DOUG @ ECS

Our instructions are on our web site, here is a link. Thanks for your interest.

http://www.eastcoastsupercharging.co...tructions.html

RpeterK

A non ecs kit car would need a slight re route from the pics but would work. Also this is for dry sump cars only. On a non ECS car the quick connector on the front of the PS valve cover needs to be routed to the inlet plenum where the line was connected from the dry sump tank originally.
This mod just puts the oil back into the engine where it belongs instead of the air plenum if it needs to purge. This modified routing will not on its own will not prevent oil from the pcv system finding its was into the plenum.
Caution The fitting in the middle of the valve cover needs to be rotated to remove it if you find it necessary to do so.

bob

567Chev

I get it now, and read the instructions as well where it is clearly described. In an n/a car (or a 2015 z51 which it looks like is running this concept), would the check valve in the front PS valve cover still be removed? Or is that removed for some reason related to boost?

RpeterK

I would remove those ***** on both sides. There will eventually be a paste like build up from the oil film and condensation that will tend to make the ***** stick. If they get stuck all the venting at that point is sent thru the pcv/check valve that is in the valley cover right into the intake. The more open vents you have the slower the air flow through them. The slower the air flow the less oil it will tend to carry with it.
The other thing is that if the motor does detonate there will probably be enough air flow to close them also at a time where they need to be open.

vettetwo

Why seat-of-the-pants second guess GM for placing the check ***** in the clean side PCV lines? If removed, any increase in crankcase pressure can push dirty air into the intake bridge ahead of the throttle body. By blocking this undesired relief path with the check *****, the crankcase pressure will push the dirty air through the PCV valve where is belongs. Even if the intake manifold vacuum drops to zero as speculated at WOT, the crankcase pressure will be greater than the intake manifold pressure and PCV flow will continue as designed using the flow into the valve covers as the clean side source.

Best practice is to check the check ***** periodically by simply removing the L-shaped connection and shaking it. A free check ball will rattle and continue to work as designed. If they do not rattle, spray in throttle body cleaner for cleaning. It is highly unlikely they will ever need cleaning because this is a clean side flow point.

Higgs Boson

We remove them because they get stuck because the clean side gets dirty just like it has for 15 years. The clean side hoses are also too small to accommodate boosted crankcase pressure relief.

The intake to valley cover hose does not flow nearly enough air to adequately vent the crankcase and people are blowing their crank seals out due to the cheap design in the LTx motors.....in fact mine is leaking right now and I am not even boosted.

So, the solutions are out there, replace the crank seal with the LSx part, replace your fresh air lines with larger diameter lines, and maybe even replace your valley cover to intake manifold hose, depending on your philosophy.

567Chev

Part of the reason I'm going with a Mightymouse PCV can inline on the valley cover to intake manifold hose on my n/a Z51, is that it has a pressure relief valve which I thought might alleviate this problem. But it's just a guess on my part. Do you think that could help?

I'm a little concerned about removing the check valves on the air bridges in case the flow reverses straight into my intake, although maybe one of the cans (like UPR) that uses a second dirty side line upstream the throttle body would help prevent it reversing in the first place?

Higgs Boson

A catch can will not alleviate crankcase pressure only catch some of the stuff that comes out of it.

I honestly do not subscribe to conspiracy theories of any kind but I do think crankcase pressure is a real issue in the LTx. I do think the PCV system runs a lot cleaner than the LS motors did with respect to keeping crankcase gasses out of the intake manifold but I guess the cost is pressure build up.

vettetwo

How does the clean side get dirty? While there is intake vacuum creating "Positive" Crankcase Ventilation, there is airflow into the valve covers over those check ***** sourced from air that has been through the air cleaner and measured by the MAF. I am curious about the non-Z51 which will never have oil in the air bridge ahead of the throttle body. If you are speaking of Z51 without an effective clean side separator or with high oil level in the dry sump oil reservoir, I can understand why the check ***** may get sticky. A better solution in my opinion is to fix the source of the oil in the air bridge.

Higgs Boson

because there is not always vacuum pulling air into the valve covers. at wot and high load conditions there can be enough crankcase pressure (especially boosted) to push air backwards through the fresh air lines, this is what happened on the LS1, LS6, LS2, LS3, LSxxxxxxx, cars since 1997. has nothing to do with dry sump.

there have been varying reports of pcv issues on the LTx. personally, my fresh air lines have not had any crankcase gasses come through backwards (I check twice a day when I brush my teeth), but quite a few have reported issues in their intake.

my issue is not with crankcase gasses reverse flowing into the intake tube, but pushing out the crank/timing cover/oil pan seal(s). not sure yet which one this time, and I am naturally aspirated on E85 with no detonation or preignition. spark plugs look perfect, etc.