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GM 1.4L Turbo Intake Manifold PCV Valve Fix Kits

665K views 908 replies 214 participants last post by  dbpd 
#1 · (Edited)
GM 1.4L Turbo Intake Manifold PCV Valve Fix Kits


Overview
These fix kits apply to the following vehicles with the GM 1.4L Turbo LUJ/LUV/A14NET engine:
2011-2016 Limited 1.4L Cruze
2011-2018 Chevy Sonic/Aveo
2015+ Chevy Trax
2015+ Buick Encore
2011+ Opel/Vauxhall Corsa (Turbo only)
2009+ Opel/Vauxhall Astra J (Turbo only)
2010+ Opel/Vauxhall Meriva B
2011+ Opel/Vauxhall Zafira Tourer


SCROLL DOWN TO THE BOTTOM OF THIS POST FOR INSTALLATION INSTRUCTIONS

The 1.4L Turbo engine (LUJ/LUV) in the Chevy Cruze/Sonic/Trax and Buick Encore has a check valve in the intake manifold that has a 100% failure rate. Out of warranty, it can cost as much as $350 to replace. There is no redesigned part for this (at the time of this post's writing), and new intake manifolds are still failing regularly after about 30,000-60,000 miles. The Dorman intake reportedly has the same flawed design. This thread presents two fix options that can be implemented for between $85 (V2) and $130 (V1), which is cheaper than all other aftermarket options.

DISCLAIMER: This solution has received validation testing and is currently considered reliable. To ensure a proper install, MAKE SURE YOU READ AND UNDERSTAND EVERYTHING IN THIS POST. Neither myself nor CruzeTalk.com accept any liability for what happens during or after the installation of this kit. This kit is only being offered for convenience; it is your responsibility to ensure that all of the components of the kit are clean and are in good operating condition. For full disclaimer, click here.

Read the first post on the following thread, which explains how our PCV system works and will help you understand the solution better:
2011-2016 Cruze Limited 1.4L PCV System Explained

The basic principle is simple. You have two chambers; the intake downstream of the throttle body, and the PCV chamber. You need to allow gas to freely flow from the PCV chamber into the intake chamber when the engine is under vacuum (not producing boost), but block that flow of gas when the engine is producing boost. You need to be able to do this while sustaining pressures of 15-30psi (stock/tuned vehicles). The OEM intake manifold check valve serves this function decently well, while it works, but the check valve stops sealing well after a few thousand miles, producing an audible boost leak, and eventually disappears altogether. This solution offers you the opportunity to cleanly retrofit a durable, leak-free external check valve that can be serviced easily and replaced for $15-$25 should the check valve itself ever fail.

Benefits to this fix kit are:
  • Eliminates boost leak caused by aged, worn, or clogged OEM check valve
  • Solves boost leak, loss of power, poor fuel economy, and oil consumption caused by missing OEM check valve
  • The new external check valve is easily accessible for cleaning, and can be replaced for $10-$20
  • Stops oil consumption caused by missing check valve. Oil consumption will cause carbon build up on the piston crown and ring lands, which can cause detonation and piston damage.
  • Much longer lasting than the OEM check valve due to more robust design.
This design is patent pending.

PCV Fix Kit Comparison
I have three kits available for fixing this PCV system. Here are here are the differences between them:

V1 Kit: This is the original PCV fix kit. This kit routes the PCV gas through a check valve into a BNR throttle body spacer. Because this kit requires a throttle body spacer, it is more expensive to use if you don't already have the spacer. However, those who already have a BNR throttle body spacer, or want one for other purposes will find the V1 kit cheaper by $10. One benefit to this kit is that the check valve can be removed for inspection or cleaning by disconnecting the throttle body spacer, which doesn't require intake manifold removal.

V2.1 Kit: I designed the original V2 kit to reduce the cost of this fix as it doens't require the BNR throttle body spacer. Instead of returning the PCV gas to a BNR throttle body spacer like the V1 kit does, the V2.1 kit uses a Y fitting on the EVAP purge line or optionally, a brake booster tee fititng. While the adapter and some components add to the cost of the kit itself, the V2 kit saves you $50 as you no longer need to buy a separate BNR throttle body spacer. Please note that the check valve cannot be easily removed for inspection without pulling the intake manifold itself. However, the check valve is extremely robust and over-built for this application. The V2 kit is also easier and quicker to install and does not require the inch-pound torque wrench you need to get the throttle body spacer and throttle body back on. Please note, however, that the optional brake booster tee fitting should be checked and cleaned (if necessary) about at least every 50,000 miles or 2 years

V3.4 Kit: The V3 kit is the most recent PCV fix kit design, with a completely top-side installation that in most cases, does not require intake manifold removal. The V.43 kit also replaces the OEM PCV pipe (the corrugated/accordion hose from the intake manifold to the turbo, which has a high rate of failure due to cracking) while re-using the terminals. The V3.4 kit's check valve is also easily serviceable without intake manifold removal.

Purchase Details:
Orders are handled on my website at CruzeKits.com.

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Alternate Order Options
Please contact me for multiple-order discounts if you need to purchase more than one kit at a time, if you need a re-install kit, or if you need any replacement parts. I can also ship overnight via UPS if needed.



Installation Instructions
V1 Fix Kit Instructions: How-To: GM 1.4L LUV/LUJ PCV Fix Kit V1 Install

V2.1 Fix Kit Instructions: Coming Soon

V3 Fix Kit Instructions:
 
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#4 ·
Great post, as this alternative is serviceable if issues arise without future intake removal.

I just wanted to mention that Rockauto has the full intake for $270 before their traditional 5% off. Granted the part might fail again, but you'll have to evaluate the current cost of a new GM intake, vs. modifications.

Also playing into this decision is the age of the car, and how long you plan on keeping it.
 
#5 ·
That about cancels out the shipping, and the manifold is still ~$270, which is about double what this fix costs, and that manifold is guaranteed to fail again. Not that the price is going to make that much of a difference; $270 is still a lot of money.
 
#11 ·
That is just unbelievable to me that they don't address the problem.
I am going to remember this the next time I spend $20,000.

I guess the only thing we can do is keep it as clean as possible.
I have been using this twice a year. When I change the oil filter in the spring and then the oil and filter in the fall.

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I do the normal throttle body cleaning according to the instructions on the can while the car is running but I check and see if I see the check valve and clean up check valve. Don't know if it makes a difference but I figure it couldn't hurt.
 
#13 ·
A $2 valve fails and you have to replace a $300 manifold?! It will be interesting to see how this solution actually performs. This is probably how it should have been designed in the first place.

This reminds me a little of the intake manifold on my old Saturn SL. The engineers decided not to put a bolt in the top outer corner of the #1 cylinder intake. About every 3 years the gasket would get sucked into the manifold in that corner and create a small vacuum leak. I didn't notice it until I failed the first smog test (which is at 5 years in California). It actually made me wonder if it was purposefully designed this way so that the dealers could make money replacing intake gaskets.
 
#19 ·
i had no indications that my check valve was gone until my 2011 eco threw P0171 and P0299 codes. Initial searches said bad turbo but i dug deeper and found XtremeRevolution's posts in the Gen1 pcv explained thread and checked the burst disk (blown, sucking air at idle) and pcv valve (gone from the intake). The car went from driving fine to not, no warning.
 
#20 ·
I think you'll find that replacing the cam cover takes you back to "driving fine" - it just won't last very long. At this point, I'm sure that the PCV valve in the cover is what controls the quantity of the flow. The other valves just control direction. But there's still some details that don't quite add up.
 
#21 ·
Initial pictures were mostly a mock up design but I've started actually fitting this to install on my car. First thing was cleaning up that intake. Took off the gaskets and used half a can of brake clean and a brush.



This next photo is a picture of the missing check valve through its port after scrubbing it with the brush. Some of that residue doesn't come off but I got the area around the hole I drilled and the check valve port cleaned.



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#22 ·
Installed the plug today. #10 stainless self-drilling screw and a 7/16" nylon washer. I used plastic epoxy to bond everything together. I used a telescoping screwdriver with a bit attachment to drive the screw in. The epoxy, washer, and screw can be purchased at any local hardware store.



First, drive the screw half way into the center hole for the check valve dry to start the thread, then back out.

Place the washer over the screw, and liberally coat the screw thread with epoxy.



Using a flathead screwdriver, liberally apply some epoxy to the check valve hole, entering from the top port.

Next, carefully, being sure not to touch the walls, drive the screw back into the hole all the way to the end. IMPORTANT NOTE; don't over-tighten the screw. Screw it in till it hits the end, then lightly tighten until it's snug.

At this point, the epoxy should have bonded to the screw, the washer, the surface of the port, and should have been pressed through the outer holes on the port to produce an excellent bond. However, if you want to use up the remaining epoxy on your mix surface, feel free to load it up around the screw wherever you feel like it.



Be sure to wipe off the screwdriver you're using after every single application. That stuff dries fast and you'll be scraping it off later.

Full cure takes 24 hours. Once it's cured, it's permanently sealed.

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#23 ·
Got the final fitment done. I discovered it works better when the reducer elbow is mounted to the hole closer to the runners. Going to install this in the next few days.





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#26 ·
So what happens with the check valve down on the turbo end of the PCV line, does that just remain closed since the existing PCV line from the intake manifold to the turbo will not be used?
 
#27 ·
It does the same thing it did before; it opens when the vehicle has positive crankcase pressure and the intake is under boost to relieve that pressure, and closes when intake pressure is less than -1/2PSI.

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#29 ·
Yes. While the new hole comes up from the bottom, if you look at the first post, you'll see that the actual intake is well above the "floor".

I do wonder if there could be some purpose to that long passageway to the old valve that's not obvious.
 
#38 ·
XR you really went above and beyond on this fix, Its robust and is = to factory operation.

Should be fully California ready
 
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#40 ·
Built my attempt at a fix, based mostly on this plan but ordering all parts but the throttle block from Amazon (I buy a lot of stuff from there). As an aside, the price for the valve cover was only $70 from the local dealership, which would have been a lot faster as they had both the valve cover and intake in stock. The intake was $470 though, so I had to wait for the other parts to get here.

I used all barbed connections. The downside is that at least between the throttle body spacer and the check valve, you need them clamped, since that'll be seeing some pressure.
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Detail shot of the nut - I only used the washer outside, based on the idea that that was the biggest sealing surface. I also went with a 1/4" to 3/8" adapter instead of the 1/4" to 1/4", so I had to step it back down before going to the angle, which also made my valve hang out a bit further - but there is plenty of room there for this. It makes me kind of surprised that they didn't go with the external valve, at least in the redesign - I wonder how much the warranty coverage cost them.
Auto part Metal


Seems to work so far. I took it for a short drive tonight. Wife will use the car as normal tomorrow. It does seem a bit more peppy than the last time I drove it, which might have been due to lost boost from the intake valve failing first. Either that, or her car is just more peppy in general than my old winter beater...
 
#41 · (Edited)
Built my attempt at a fix, based mostly on this plan but ordering all parts but the throttle block from Amazon (I buy a lot of stuff from there). As an aside, the price for the valve cover was only $70 from the local dealership, which would have been a lot faster as they had both the valve cover and intake in stock. The intake was $470 though, so I had to wait for the other parts to get here.

I used all barbed connections. The downside is that at least between the throttle body spacer and the check valve, you need them clamped, since that'll be seeing some pressure.
View attachment 218114

Detail shot of the nut - I only used the washer outside, based on the idea that that was the biggest sealing surface. I also went with a 1/4" to 3/8" adapter instead of the 1/4" to 1/4", so I had to step it back down before going to the angle, which also made my valve hang out a bit further - but there is plenty of room there for this. It makes me kind of surprised that they didn't go with the external valve, at least in the redesign - I wonder how much the warranty coverage cost them.
View attachment 218122

Seems to work so far. I took it for a short drive tonight. Wife will use the car as normal tomorrow. It does seem a bit more peppy than the last time I drove it, which might have been due to lost boost from the intake valve failing first. Either that, or her car is just more peppy in general than my old winter beater...
My design initially used a brass ball check valve. The problem with that check valve is that the crack pressure was too high. You see, we don't have all that much vacuum on this engine. At idle, the intake pulls -2.5 psi of vacuum. Refer to the attached image. This was taken by a fellow member, in gear, AC on, 74 degrees out. The hotter it gets, the less vacuum we have. 6inHg = -3 PSI. I also attached another image from another member that used a ScanGauge.

Every resource I found on those 1/4" aluminum check valves (which are designed for fuel) indicated a -3 PSI crack pressure. The most difficult part of this project was finding a suitable check valve that would crack open at a similar pressure as the OEM check valve, which was barely under 0 PSI. The check valve I found (and linked in the original post) has a crack pressure of 1/2 PSI.

Produzione di articolo 100012%20LF - LEAD FREE PRODUCT - IN-LINE CHECK VALVE - Vendita di RUBINETTERIE BRESCIANE | www.bonominorthamerica.com

I spent many hours looking for this check valve. Your check valve cracks at too high a pressure and as a result, will direct too much (and in most cases, all) PCV gas through the turbo inlet.

I would strongly recommend revising your design to include the Bonomi check valve, unless you can find another one that cracks at a comparable pressure for a comparable price.
 

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#42 ·
Finally installed this on my car today. I'll make a tutorial on pulling the intake manifold as well soon

Drove 34 miles, 30 of which were highway. No leaks, and no problems so far.







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#43 ·
Got mine installed Sunday. The first day was ok until it got fully hot and then I got the cel and lower power. Turns out the hose I used was too weak and collapsed. Just swapped it for some extremely thick 3/8" oil hose (Amazon only had 3/8" barb not 1/4") and upon startup I had no cel. Tomorrow will tell but at first it ran like a champ


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#45 · (Edited)
2011-2016 Cruze 1.4L Turbo Intake Manifold PCV Check Valve Fix

Same configuration exactly. The hose I had on hand was I thought strong enough but it didn't have a braided core. I was hopeful but when I checked it had collapsed and then seemed to have gotten malleable and stayed collapsed. The new hose has nearly 1/4" thick walls with a thick braided core and barely bends. I checked at idle and it was just as rigid as before, we shall see how it is tomorrow

The only difference between our setups was that they were sold out of 1/4" barbed fittings so I got appropriate 3/8" fittings.


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#46 ·
Here's the stuff I used. I added a link to this in the original post so people have a better idea of what they should be looking for.

https://www.amazon.com/gp/product/B...OFRD6&linkId=4ca8ea55754a8dbed702ee1142580266

I'm still really confused why you had a CEL and low power. You sure you didn't forget to plug something in or maybe had something unrelated going on? Even if this hose fails, it shouldn't throw a CEL unless it doesn't seal correctly and starts leaking at the barbs, which I suppose is a possibility.
 
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