Fixing the intake manifold and PCV for good

[Flyer]

I originally posted this in another thread. After thinking about it, it was a lot of information and may should have gone in a new thread so not to take away from that original thread.

I have come across a used intake (missing a poppet in the PCV) and a valve cover or 2 or 3 leaking in the top. I set out with the goal of re-configuring the PCV and fixing a couple of things more long term. I had 2 issues that were prompting me to do this. One, every time the bypass valve would actuate I would get a puff of smoke out of it. I could feel a slight loss of power, but it wasn't consistent. Also I was having a problem on a hard pull, if I didn't shift before 6k it should cut out pretty bad. Sometimes it would clear right up and sometimes it would last long enough to trigger limp mode and a P0300.

In my opinion it's absurd to replace a $300 part for a 10 cent piece that should have never become a problem anyways. Also ... when the little red button disappears from the PCV it creates other problems. Then we have the problem with the valve cover leaking under the beauty shield. Then the lesser known poppet (same as the red button in the PCV) that lets vacuum into the canister attached to the bottom of the intake manifold.

Here is a pic of the bladder on the bottom being cut off. It's worth mentioning there was heavy oil residue in this when I removed it. I don't recall any liquid coming out.

This pic is 2 intakes sitting side by side looking at the bottom side of the intake. This is the area for the bypass the bypass mod.

Here's the manifold where it bolts to the head. You can see the PCV runner filled with silicone and the porting on the intake. The port the hose hooks to on top is also filled in with silicone in the same way

This is the modified valve cover and the catch can. The spot where the diaphragm was is now hollowed out with a 3/4 pipe fitting shoved in there to vent the baffled area. There is a 3/8 hose attached to that fitting which is vented to the atmosphere through a catch can and filter.

This is showing the bottom side of the valve cover. The silicone is where the Unibit went all the way through trying to cut the hole for the pipe fitting a little bigger. If you will notice the raised area, that looks like it's channels in the cover ... are just that. They go between the top center channels and the one in the bottom center. The bottom center is where the intake PCV runner gets to ultimately. I'm not sure how far or where they go from the head. Those channels in the cover also go to the little burst disc (I'm not sure that's the correct term for it) on the cover where they are notorious for leaking and requiring replacement.



So ... in doing these things to mine, I have permanently corrected the leaking valve cover and the poppet valve in the intake manifold. As a side effect, I have also completely removed the PCV from the intake of the engine so that anything from the PCV will ever be introduced back into the intake tract. The new PCV vent is protected from oil splash and uses the channels and chambers already built into the cover for PCV routing.

I'm not so sure I narrated that last pic very well so please ask if you have questions. I'll also get a pic of it on the car if I remember tomorrow.

Full disclosure ... I got the idea from someone on the HPTuners board with a 1.4T in a dedicated race vehicle (not an original application). Thank you Sprinto7!

Last thread is an update after using for some time. Also more detailed on the catch can.

 

[Flyer]

Something else worth mentioning, in this method of 'bypassing the bypass', it will throw a P0033 and go into a limp mode making no boost. It is necessary to change the P0033, P0034, and P0035 codes in the ECM tune to 'No error reported' (that's what it's labeled in HPTuners).

Also added a pic of the top of the intake manifold to show the PCV hose port blocked off again with silicone.

Collectively there is a tube and a half of silicone on this manifold.

This is also a GREAT time to do Injectors and manifold porting.

 

[carsNskis]

Nice work. The write up might be a little easier to follow for some if you split the text up with the images, bit overall this is great info!

Side note, I didn't get any CELs running the "bypass x3"... are they pending codes? I'm assuming you're running HPtuner to correct the code issues?

 

[Flyer]

Nice work. The write up might be a little easier to follow for some if you split the text up with the images, bit overall this is great info!

Side note, I didn't get any CELs running the "bypass x3"... are they pending codes? I'm assuming you're running HPtuner to correct the code issues?

Thanks, agree with the pics. I didn't host them anywhere and not sure on embedding them into the post.

The solenoid is gone on mine. The P0033 is for an open circuit, which it is .. since it's not plugged in.

 

[Flyer]

Fixed

 

[Flyer]

Update after running it a few days. The car seems to run SOOO much better than it has in a very long time. I wished I'd have done this a long time ago.

I've had the parts and pieces riding around in the back for a while but haven't done anything with them until Monday. If anyone is considering this ... I'd highly recommend it.

I have another intake and valve cover I'm going to use for my wife's Cruze, maybe ...

After that, I would be willing to sell the spares if anyone is interested. I will admit it was much easier to work on these items having some spares.

 

[ScarabEpic22]

What kind of silicone are you using to block the areas off? Have you taken into account the difference in manifold volume after removing the expansion/bubble tank? Or seen any differences in the AFR, spool time, or power delivery with it gone?

 

[Maddmatts]

Nothing should really change by removing the tank. It's one purpose is to 'store' vacuum for the computer to use to actuate the turbo's bypass valve under boost. It's closed off with a check valve except at idle or decelleration.

 

[Flyer]

Maddmatts is right. The only time it was a factor is when vacuum in the manifold was greater than vacuum in the canister.

The car runs better all around. It seems to spool a little quicker (keep in mind the manifold was missing the poppet for the PCV too), it's more responsove, runs smoother, better, and just generally feels better. The bypass valve also seems to be a little more crisp and quicker to react.

That is GMs gasket silicone. I forget the part number but it cones in a tube with a tip and key to turn the bottom of the tube. It is the same stuff that holds the oil pan on your engine ... Minus the bolts.

It is worth mentioning that the tech had to play with the manifold to get it out but the one without the canister went in with no problem.

 

[Llia]

Is this like the Bypass mod, only it completely removes the vacuum storage tank and solenoid?

So what are you using in place of the PCV or check valves? Where does the PCV vent to then, I only see the brass fitting on the valve cover but not where it connects to.

Could you buy your own PCV valve and vacuum canister and run an easier to maintain system to keep it like stock?

BMW 07-10 335i has a nice remote vacuum reservoir. Simple inlet and outlet, maybe an internal check valve?

 

[Flyer]

If you look at the 4th pic in the first post, the brass fitting ends up at the catch can. That's the extent of the PCV system. It goes from the catch can into a stand alone filter that's behind my MPFab CAI shield.

I did pull all the guts out of the burst disc and seal off the vent.

 

[EPYON96R]

So if I bypassed the bypass already, do I not need the tank on the IM? My orange disk(check valve)popped out who knows how long ago and I am trying to buy a new manifold, but do I really need to if I have done the bypass mod??????

 

[Flyer]

The ideal thing to fix your manifold without replacing it is to pull it and do what I did. You can expect your car to be down for at least a day though. The silicone needs time to cure and adhere to the plastic on the intake.

The vacuum bladder was my curiousity more than anything. I cut one off just to see if it was open to the intake or connected at all. We have our answer.

This did bypass the bypass in a more permanent way.

I do question the need to cut the tank off and plug that hole, but I know now it's not going to loose it's little poppet valve, nor will it leak any boost or vacuum.

On a side note the intake is really easy to come in and out as oppose to having to wiggle it out with that big bladder on the intake.

 

[2014 Blue RS]

Did the intake and injector upgrade long ago. Where's this "burst disc"?

 

[Flyer]

In the valve cover, what always leaks.

 

[Llia]

Am I seeing the wrong pics? The 3rd pic just looks like a shot of the intake manifold.

 

[2014 Blue RS]

I don't see any burst disc. Hmm

 

[Flyer]

Am I seeing the wrong pics? The 3rd pic just looks like a shot of the intake manifold.

You are correct. I'm sorry. It is the 4th pic. The one with the cover and the catch can. The brass fitting is where the burst disc is. There was some silicone rubber type material in there with a spring. They were mangled past the point of recognition when I pulled them out.

That brass fitting is now my PCV vent. That brass fitting has a hose attached to it that goes directly to my catch can.

 

[Llia]

You mentioned drilling too deep. Is there a passage in the burst disk in between layers? The filler you added was just to cover a hole beneath the brass.

 

[mja]

'burst disk', 'cam cover diaphragm', 'pcv failsafe', all the same


Which is my biggest critique with this mod. This is alright on a dedicated race engine but not for a street car. What happens in the stock setup when the check valves fail and you build crankcase boost? Blows the burst disk/cam cover diaphragm. This diaphragm sucks close under vacuum and the car works well at part throttle. But then it shuts down applied boost and powers the car in limp mode by pulling in unmetered air. Its purpose is to save the motor and frustrate you until you've replaced all necessary PCV equipment.

What happens when you block off the check valve and the diaphragm? The ECM throws codes saying, if my crankcase boosts I can't do a thing about it, so ima dumb down the power for this operator.

Then the operator removes those codes, and all is well. Until one day, a few months or some years later when boost is sent to the crankcase and oil blows out of the pan exposing bearings to ridiculous air pressures and low oil pressure. Boom time.

I agree replacing the intake mani is insane and expensive, 250-350$ for a new one. I wouldn't buy one used at all because of this check valve. To do it right, you can block and re-route the intake mani check orange check valve, but you gota replace with an inline check valve for safety.

The cam cover is what like 70-80$? I mean you could probably rig up a breaker style diaphragm but at that price, I think you should worry more about can you afford basic car maintenance.

Edit:
Also folks, those 'raised areas' on the top side of the cam cover are baffles, it baffles oil to save it from dumping into the intake when the car is cold or has lots of crap in oil. Similar to what a catch can does. This is the factory's 'catch can' so to speak. If you're blowing oil in a big way through the turbo inlet, it's time to think about changing out all your PCV components. It should be dry. A catch can will add more peace of mind to this system, but it shouldn't be used as a crutch.