# 2014 Cruse LS 1.8L vacuum leak P0171



## bsdubois (Jul 13, 2017)

My Daughter’s 2014 Chevy Cruze LS has a CEL with code P0171. It idles rough and the performance is subpar. 

I heard what sounds like a vacuum leak. I found a YouTube video that shows how to check the purge control valve as they are known to stay in the open position. I removed the power connector and the hose with the red resting clip. My Daughter started the car and no leak.

I finally discovered the location of the vacuum leak. It is on the plastic air intake manifold on the right (passenger) rear side of the manifold. There is a vertical slot at this location (photo included below.) I covered the slot with my finger and this stopped the vacuum leak. I am uncertain if this leak is caused by a defective diaphragm in the plastic valve cover that is part of the PCV system, or, if this is a defect inside the intake manifold.

All the videos I have found that show a leaking PCV are for the 1.4L turbocharged Engine.

Her car is the 1.8L normally aspirated in line four cylinder.

I do not mind replacing both parts, however, I do not want to waste over $350.00 in parts if the plastic intake manifold is not defective.

The car has approximately 120K miles. It is out of warranty. Going to the dealer is not an option.

I replaced the plastic coolant return housing. It developed a small crack. The new GM part is all aluminum. Clearly GM made a mistake with the plastic part. GM offered no help. We ordered an aftermarket part (1/3 of the price) and I had it fixed in about 45 minutes.

We greatly appreciate any help or suggestions (other than the scrap yard.)

Sincerely,

Brían S. Du Bois
Evansville, IN


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## obermd (Mar 3, 2012)

Based on the three posts you've made, you've decided this car will never be right. Get rid of it and go get something else. This isn't me speaking as a moderator but me speaking with decades of watching people decide to "tough it out" with buyer's remorse and never being happy as a result. Life is too short to live like this.


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## bsdubois (Jul 13, 2017)

That is easy to say. My Daughter started out with this ad her first car. It is real easy to say get rid of it. She should not have to. It clearly demonstrates GM’s does not care about their customers or employees.

It is a **** shame the taxpayers bailed out
GM. They should have let them go belly up. I am glad they saved the jobs of working men and women.


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## MP81 (Jul 20, 2015)

It's a used car - what exactly do they owe you?

Oh, wait, nothing.

Ford will say the same. FCA will say the same. Honda, Toyota, Nissan - anyone will say the same. It's used, and out of warranty - and then you'll throw a little temper tantrum because they are not bending over backwards for you.

I think they'd much rather "lose a customer" than have one like you.


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## bsdubois (Jul 13, 2017)

Spoken like a true GM troll


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## MP81 (Jul 20, 2015)

I'm not the troll here. 

Go back and hide under your bridge.


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## plano-doug (Jul 1, 2015)

bsdubois said:


> I finally discovered the location of the vacuum leak. It is on the plastic air intake manifold on the right (passenger) rear side of the manifold. There is a vertical slot at this location (photo included below.) I covered the slot with my finger and this stopped the vacuum leak. I am uncertain if this leak is caused by a defective diaphragm in the plastic valve cover that is part of the PCV system, or, if this is a defect inside the intake manifold.


I finally got a chance to look at my 2013 1.8. I found the slot you're talking about. At idle, I detect no vacuum there with a wet finger.

I suspect there's something wrong with your intake, but I haven't torn into one of these so I can't speculate with any authority.

In your case, if you can get a piece of tape to stay attached, and the check engine light goes away, I'd keep driving it as long as you can. There may be a more durable fix than tape, but keep in mind, any sort of filler you put down that hole could get sucked into the engine and possibly do damage. I'd just keep tape on it as long as you can. 

After that, you're probably looking at removing the intake so you can do a proper repair to it, or replacing it altogether.

My 2 cents. YMMV.

HTH.









Doug


.


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## bsdubois (Jul 13, 2017)

Doug, thank you for your kind reply and taking time to check your intake.

I had the idea of disconnecting the PVC hose from the intake near the throttle. I was attempting to rule out yeh pressure (BMW style) regulator in the plastic valve cover. This
Caused a large vacuum leak and the car stalled.

I checked with the dealer and the intake manifold is $600.00 list. I found an AC Delco for $320.00 and free shipping.

I thought about tape and I will give it a try. The reason for the vertical slot is not evident. It makes one wonder if it is an intentional failure point. The replacement part is made in Poland arrording to the photo of one box I saw.

I would like to find an aluminum replacement.

Thank you again for your time and assistance.

Sincerely,

Brían S Du Bois


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## obermd (Mar 3, 2012)

That hole is too clean to be a failure. I suspect your daughter bought a used car that had been modified at some point and when being sold the modifications were removed without repairing the damage left behind by the intentional modification.


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## Blasirl (Mar 31, 2015)

bsdubois said:


> My Daughter’s 2014 Chevy Cruze LS has a CEL with code P0171.
> 
> I do not mind replacing both parts, however, I do not want to waste over $350.00 in parts if the plastic intake manifold is not defective.



I suggest you buy one from a Pick N Pull or LKQ yard.






LKQ - Evansville - LKQ Corp


LKQ - Evansville - 2139 Kotter Avenue, Evansville, IN 47715




www.lkqcorp.com





or 






Keystone Automotive Industries - Evansville - LKQ Corp


Keystone Automotive Industries - Evansville - 2300 Kotter Avenue, Evansville, IN 47715




www.lkqcorp.com





P0171:

A code P0171 may mean that one or more of the following has happened: 

The MAF (Mass Air Flow) Sensor is dirty or faulty Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry. 
There could be a vacuum leak downstream of the MAF sensor 
Possible cracked vacuum or PCV line/connection 
Faulty or stuck open PCV valve 
Failed or faulty oxygen sensor (bank 1, sensor 1) 
Sticking/plugged or failed fuel injector Low fuel pressure (possible plugged/dirty fuel filter!) 
Exhaust leak between engine and first oxygen sensor

Read more at: https://www.obd-codes.com/p0171


*I did not vet any of this.*





'12 Sonic throwing code P0171 (2012, gasket, fuel, exhaust) - Automotive -Sports cars, sedans, coupes, SUVs, trucks, motorcycles, tickets, dealers, repairs, gasoline, drivers... - City-Data Forum


I have a 2012 Chevy Sonic (1.8L auto) with about 35K on the clock. About two months ago I got an oil change; on the first cold (below freezing) day



www.city-data.com


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## Brandonrojas (Feb 19, 2021)

bsdubois said:


> My Daughter’s 2014 Chevy Cruze LS has a CEL with code P0171. It idles rough and the performance is subpar.
> 
> I heard what sounds like a vacuum leak. I found a YouTube video that shows how to check the purge control valve as they are known to stay in the open position. I removed the power connector and the hose with the red resting clip. My Daughter started the car and no leak.
> 
> ...


*hello I have 2015 sonic 1.8l im having the same issue, p0171, and p0011, that slot next to throttle body on intake manifold is sucking air as well, also my car has rough start and this morning the check engine light was flashing and traction control light was on so, i pulled my coil pack out and discovered today there was a bunch of oil in my spark plugs, if anyone can help that would be amazing*


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