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My son has a 2012 Cruze that was throwing 171 and 1101 code. Valve cover fixed the 171 code and we finally took it to dealer after cleaning map, maf, and throttle body and replacing air filter. They came back and said it was the PCV tube from intake to turbo. So we ordered it and got it installed and it fixed the code but, now rpm fluctuates from 500 to 900 at idle and while stopped in gear and neutral also. It drives fine down the highway but at stop lights and while parked rpms fluctuate. I've sprayed around with carb cleaner and can't find any vaccum leaks. We put old PCV tube back on and fixed idle issue but now we're back to throwing 1101 code. Thanks for any help!
 

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Discussion Starter #2
The old PCV tube is bad. The check valve is stuck open. You can blow air threw it both directions. The new only lets air into the turbo but has a check valve to prevent air going into intake.
 

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You're in the right place but your codes are confusing.

For example, you indicate a code 171........no such thing.....but based off your description I am able to figure out you are reporting a P0171...a vacuum code often caused by a failed PCV.
You indicate that was addressed by cam cover replacement.....so far, so good, however.........

1101 code????????PCV tube?

We aren't speaking the same language on that one so details and maybe a photo of this 'tube' could help.

Miles and engine info would help......miles in particular.....I'm assuming we are discussing a 1.4t.

Rob
 

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Discussion Starter #5
Sorry for the confusion. Yes it was a p0171 code that is fixed now we have a p1101. The car is a 2012 Chevrolet Cruze 1.4 turbo with 110000 miles. The problem that was diagnosed by Chevy dealer was PCV tube. We replaced it and fixed the code but now the rpm fluctuate at idle from 500-900 rpm. The PCV tube goes from intake to turbo across the top of valve cover just above syrpentine belt. Just wonder if anyone has had this same issue. image.jpg
 

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The RPM fluctuation is a sign of a vacuum leak. The fact that you don't have another P0171 says the leak isn't large enough to set the code, but the RPM fluctuations says you have a leak. Double check your work to ensure everything is seated properly and tight.
 

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Sorry for the confusion. Yes it was a p0171 code that is fixed now we have a p1101. The car is a 2012 Chevrolet Cruze 1.4 turbo with 110000 miles. The problem that was diagnosed by Chevy dealer was PCV tube. We replaced it and fixed the code but now the rpm fluctuate at idle from 500-900 rpm. The PCV tube goes from intake to turbo across the top of valve cover just above syrpentine belt. Just wonder if anyone has had this same issue. View attachment 174890
OK good,
That helps.

I might ruin your day though.

Remove the hose pictured at the manifold.
Look down the hole in the manifold......you should see the tip of a plastic valve.....kindof brownish, tanish in color.....gets a bit discolored over the miles.

I'm betting you will not see the valve.....if I am correct, you have found out why the PCV failed......if the valve sticks open (cannot see tip) the PCV is under tremendous vacuum and pressure moments depending on intake pressure and it'll only put up with that just so long.
This will explain the wacky idle and additional code.

If you see no valve, the car will require intake manifold replacement......it only comes as a assembly that includes injectors and a throttle body.

Keep in touch,

Rob
 

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The old PCV tube is bad. The check valve is stuck open. You can blow air threw it both directions. The new only lets air into the turbo but has a check valve to prevent air going into intake.
I thought there was a check valve in the manifold that did that function. Did Chevy come out with a replacement part so they wouldn't have to replace the entire manifold when it failed under warranty?
 

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Discussion Starter #10
The new tube (pictured) I just got from gm has a check valve on the end that connect to turbo. I cannot blow towards the manifold but i can push air toward turbo. The old tube I pulled off has no restriction either direction. Not sure if that's new or if the old one was bad and originally worked the way the new one does?
 

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The new tube (pictured) I just got from gm has a check valve on the end that connect to turbo. I cannot blow towards the manifold but i can push air toward turbo. The old tube I pulled off has no restriction either direction. Not sure if that's new or if the old one was bad and originally worked the way the new one does?
So the question is if the old tube failed, or has the part changed? A look inside may answer that question.
 

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Discussion Starter #12
By looking at the parts they are identical. The end that connects to the turbo is where the check valve is and they both look the same. So I guess it's a failed part. But the big question is why did it fail? Just a worn out part or is it the part inside the intake that was mentioned in a previous post that caused the part to fail? As soon as my son get back to town I will look it over good and post our findings! We put the old PCV tube back on cause he didn't like the idle fluctuating. He is off at college so we want to try and keep him in a decent ride! Thanks for all the help!!
 

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Hey, I've gone 6,000 miles now with a stuck orange check valve in the intake manifold, and my Cruze is still running fine with no codes.

I think the 1101 code is from something else other than the check valve. Just to be clear, did you do all the work yourself, and only took it to the dealer for a diagnoses?

... Valve cover fixed the 171 code and we finally took it to dealer after cleaning map, maf, and throttle body and replacing air filter. They came back and said it was the PCV tube from intake to turbo. So we ordered it and got it installed and it fixed the code but, now rpm fluctuates from 500 to 900 at idle and while stopped in gear and neutral also...
The way this reads, it sounds like you could be saying the dealer replaced the PCV tube. If that's the case, then obviously you wouldn't have driven out of the dealership without it being fixed at that moment, and this would mean at some point later the idle started fluctuating. There are reports of the valve cover failing again in as little as 7,000 miles afterwards because of the stuck check valve (which would explain the rough idle), but most go longer than that until failure again.

I've sprayed around with carb cleaner and can't find any vaccum leaks. We put old PCV tube back on and fixed idle issue but now we're back to throwing 1101 code. Thanks for any help!
As for this, I don't know. :icon_scratch:
 

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Discussion Starter #14
No we've done all the work ourself. Dealer was just for diagnosis. My son is 150 miles away in college so when he comes back down I'll check the orange check valve in cover. The idle fluctuation started as soon as I put new PCV tube on. The code stayed off just has the fluctuating idle. So he wanted old hose back on to go back to school the next day and the code came back almost instantly.!The check valve in the old PCV tube is bad. It does run fine just has the check engine light on. If it was up to him he would just drive it as is.
 

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I had the exact same issue as you Hotrod. I had the 1101 code and replaced the PCV tube. I also noticed that the check valve on the new part was not working properly as you have described. Put on the new tube with a proper working check valve and now the car will not idle properly. RPM fluctuates between ~600 - 800. I removed the new tube and looked into the intake manifold, sure enough the orange diaphragm is nowhere to be seen. So the intake manifold needs to be replaced...a $1400 part. Of course my 5 year/100k power train warranty ran out in November. I'm going to head to the dealer tomorrow and see if they can help me out. This is clearly a design flaw. The fact you need to replace a $1400 part to fix a PCV issue is insane.

Does anyone know if there is any recall or TSB for this issue?
 

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Robby, you are correct! My son made it home from college and I pulled the PCV tube off the intake and there was nothing there but a empty hole! so where did check valve go? I'm assuming it's just sitting down in the intake some where. So my only option is replacing the intake?
Thanks!!
 

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Robby, you are correct! My son made it home from college and I pulled the PCV tube off the intake and there was nothing there but a empty hole! so where did check valve go? I'm assuming it's just sitting down in the intake some where. So my only option is replacing the intake?
Thanks!!
To be clear, the hole is open......you look down into the hole for the tip of the valve which is at 90 degrees on the engine side......there is a photo on some past posts of what a good one vs jammed one looks like.......maybe jblackburn??

Anyways, it doesn't fall out, it jams into the port it is supposed to control......when jammed in, the tip can't be seen.

I'm trying to clarify so you don't replace a still serviceable part........so, hopefully a member will link to the photograph I remember seeing.

Rob
 

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Hi!
Could you please give me a part number for the pcv pipe as I'm experiencing similar problems and am trying to get to the bottom of it.
Thanks in advance!
 

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Has anyone torn into the intake manifold to see why the check valves are jamming up? I just found mine jammed today and want to do everything I can to avoid giving GM $300 for a new intake assembly.
 
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