# Vacuum regulator failed with P0171 code



## Blasirl (Mar 31, 2015)

[h=1]2011-2016 Cruze 1.4L PCV System Explained[/h]
[h=1]2011-2016 Cruze 1.4 PCV Valve Cover/Intake Manifold Issues[/h]
[h=1]GM 1.4L Turbo Intake Manifold PCV Valve Fix Kits[/h]





[h=1]GM 1.4L Turbo LUV/LUJ Boost Leak Testing Kits[/h]


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## Jcote (Oct 18, 2018)

Blasirl said:


> *2011-2016 Cruze 1.4L PCV System Explained*
> 
> 
> *2011-2016 Cruze 1.4 PCV Valve Cover/Intake Manifold Issues*
> ...


I checked all this out. I think I’ll either replace the intake manifold or get the kit. Although my check valve is still present would I be wrong to believe the sick/blow principal for the intake check valve would work.. 

i placed a hose use over the intake where corrugated pipe goes into manifold and blew into it.. check valve did not close. Also sucked on same pipe and valve still did not close. Would this indicate valve is stuck? Or would this method not be accurate? 

If if it was not for the turbo passing oil into the intake. I probably wouldn’t think twice about only replacing g the cam cover. I don’t believe just a failed vacuum regular would cause this would it. Seems like it would be more related to manifold? Causing both issues?


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## Jcote (Oct 18, 2018)

So I replaced my cam cover today, removed innercooler and piping, flushed oil from them, reinstalled and attempted to start the car after clearing the code. The engine started for about 3 seconds and hen quit it took a while to get it to restart I am assuming this is because of messed of fuel trims. 

Also I pressure tested the intake system as per the video posted above. I do have leaks but the leaks are crank case leaks and here are signs of oil leaking in these places too. Which intend to fix in a few days or so. 

But I have a question. If I remove the line coming out of the intake manifold which is part of Pcv system there is a constant low flow of air is this a sign of bad check valve in manifold or is some leakage here if line is removed normal: there is nothing coming back from turbo hose. wood this be because crank case is pressurized too? With equalization in both sides of check valve?


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## mechguy78 (Jun 6, 2016)

Jcote said:


> i placed a hose use over the intake where corrugated pipe goes into manifold and blew into it.. check valve did not close. Also sucked on same pipe and valve still did not close. Would this indicate valve is stuck?


I would say that per this description that the check valve in the intake has failed. If it was working correctly it would have acted like the hose going to the turbo, airflow one way but not the other. 

Either replacing the intake or fixing it using Extemerevolution’s kit will fix the issue of the failed check valve. If it were me I’d use Extreme’s kit, but the choice is yours. 

Good of luck and keep us posted.


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## Jcote (Oct 18, 2018)

mechguy78 said:


> I would say that per this description that the check valve in the intake has failed. If it was working correctly it would have acted like the hose going to the turbo, airflow one way but not the other.
> 
> Either replacing the intake or fixing it using Extemerevolution’s kit will fix the issue of the failed check valve. If it were me I’d use Extreme’s kit, but the choice is yours.
> 
> Good of luck and keep us posted.


I think I will use the fix kit as it’s 105$ vs 280 at my dealer. And it’s proven to fail


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