suitcasejefferson
Member
Is it normal to have vacuum at the PCV valve? I do, and according to a couple of YouTube videos, I shouldn't have. I'm looking for the source of a P0171 code. I have determined it is not the purge valve.
PCV valve 1.4
- Thread starter suitcasejefferson
- Start date
No its not.
Look here: 2011-2016 Cruze 1.4 PCV Valve Cover/Intake Manifold Issues
And here: GM 1.4L LUV/LUJ Intake Manifold PCV Fix Kits
Look here: 2011-2016 Cruze 1.4 PCV Valve Cover/Intake Manifold Issues
And here: GM 1.4L LUV/LUJ Intake Manifold PCV Fix Kits
suitcasejefferson
Member
I'm talking about the round thing under the cover, above the oil fill cap. It has a small vent in it which faces the front of the car, and there is vacuum at that vent. I have a CEL code P0171 lean condition. I know there is another "PCV" valve that connects to the turbo inlet, I found that while replacing the water pump. But it seems to be ok. I have already replaced the purge valve. It had been making a very noticeable ticking noise for several thousand miles, then the engine started running rough at idle, and the CEL came on. I replaced the purge valve, the ticking stopped, and the engine now runs much better. But the light is still on, and I have not been able to find a vacuum leak around the purge valve connections. That's when I started looking for something else, and found the vacuum leak under the cover.
If there is not supposed to be a vacuum leak there, then I guess I need to replace the cover, clear the code, and see if the CEL light comes back on. If it doesn't, I need to replace/repair the check valve. Any information on this would be most appreciated.
If there is not supposed to be a vacuum leak there, then I guess I need to replace the cover, clear the code, and see if the CEL light comes back on. If it doesn't, I need to replace/repair the check valve. Any information on this would be most appreciated.
Tormach
Member
Ya, that is the pressure regulator disk in the valve/cam cover.
Is it whistling/pulling in air? Put your finger over the hole does it stop, if so it's busted and you need a new cover.
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suitcasejefferson
Member
It's not really whistling, but there is a pretty strong vacuum at that little hole. I'll order a new cover. Thanks
Pirate Luke
Member
As you've probably read, NORMALLY when that pressure regulator disk in the valve cover goes it's a byproduct of an issue with your check valve in the intake manifold. You also have one at the turbo inlet that can fail, as you noted.
I only stress checking that check valve in the intake manifold thoroughly because I had a rough idle issue that I spent a while tracking down to that special little orange rubber piece. Mine was still there and functioning *MOST* of the time leading me to check everything else, but it turns out oil residue on the inside of the manifold was causing it to stick in either direction and clog those holes at the check valve.
If your new valve cover also fails soon, I'd bet it's that check valve.
I only stress checking that check valve in the intake manifold thoroughly because I had a rough idle issue that I spent a while tracking down to that special little orange rubber piece. Mine was still there and functioning *MOST* of the time leading me to check everything else, but it turns out oil residue on the inside of the manifold was causing it to stick in either direction and clog those holes at the check valve.
If your new valve cover also fails soon, I'd bet it's that check valve.
suitcasejefferson
Member
Sorry about all the questions, but I have never had a car quite like this. Many Sonic owners probably don't know the same engine was available in the Cruze. Since there is no service manual for the Sonic, I subscribed to an online version of the Haynes Cruze manual. However, it is pretty much worthless when it comes to issues like this.
I replaced the valve cover with one from my local Chevy dealer ($93 inc tax) and installed it. I cleared the codes, and the CEL has not come back on so far. It's been about 3 days and 500 miles with over 20 engine starts.
I appreciate all the information. I have a much better idea what I'm dealing with now. But I'm not very happy with the way this car was designed and built. Apparently GM didn't do much testing with this engine before putting it on the market.
Maddmatts
Member
Sonic Service manual: Chevrolet Sonic owners & service manuals, user guides
It's free but the search function doesn't work so finding stuff can be a pain.
It's free but the search function doesn't work so finding stuff can be a pain.
JTee2017
Well-known member
Also. . it seems to contain info mostly for the 1.6L and 1.8L engines. I only found a few references to the 1.4L turbo.
Well crap.
Thanks for the help. Unfortunately, it looks like bad news on my end. I checked the stuff linked above and I suspect I'm due for a new valve cover and manifold. At this point, thinking I may just do the valve cover to clear the code and trade this turd in. I used to always like Chevy products but this thing is nickel and diming me to death.
Thanks for the help. Unfortunately, it looks like bad news on my end. I checked the stuff linked above and I suspect I'm due for a new valve cover and manifold. At this point, thinking I may just do the valve cover to clear the code and trade this turd in. I used to always like Chevy products but this thing is nickel and diming me to death.
suitcasejefferson
Member
I will likely keep mine. I paid $5000 for it with 51,000 miles on it, spent about $1500 on repair and maintenance parts, and would be lucky to get $3000 out of it as a trade in. I did get all the Dexkill out of it, that will hopefully save the cooling system. Some of it's issues were due to abuse and lack of maintenance. When the rubber thing in the manifold ruptures, it causes a CEL, but the engine still runs fine. I don't believe it will leave me stranded. I have made 6 trips from Phoenix, AZ to Portland, OR and back in it, one with the CEL on all the way there and back. In AZ we have emissions testing every 2 years, and that's the only time you can't have any stored codes. After replacing the valve cover, the CEL went out in a couple of days, I checked and there were no stored codes. I can do all my own work, so for me replacing the parts once in a while is a lot cheaper than buying a new car. If it was a sedan I'd probably try to sell it. But I really like my Victory Red hatch.
Pirate Luke
Member
That orange rubber check valve is a vital piece of the engines ability to switch between boost and vacuum. It can cause a lot more problems long term if not fixed.
Honestly, you can get just the intake manifold with the orange rubber check valve (part 25200449), the valve cover, and the corrugated hose with the check valve at the turbo (essentially replacing your entire problematic PCV system) for less than $250-$260 brand new via amazon. That's cheap peace of mind, and hella cheaper than a failed turbo or constantly replacing your valve covers, which WILL continue to fail if that rubber piece is gone.
I have a thread that discusses my issues with the system which also links to everything to explain the PCV system (http://www.sonicownersforum.com/forum/1-4l-turbo-sonic-engine-discussion/23255-rough-idle-gear-while-stopped.html) because it's the one thing on this car that can stealthily cause many peoples issues (think lower mpg, inability to hold boost, failing valve covers, oil in charge pipes, rough idle).
Basically even with the orange rubber check valve there, once oil residue gets in there it's going to suffer in efficiency. This can happen at 1,000 miles, or 100,000 miles like in my case. It all depends on how you drive the car, and if it's tuned or not. It's a poorly designed system that needs to be maintained, but isn't mentioned to be maintained anywhere by GM.
Honestly, you can get just the intake manifold with the orange rubber check valve (part 25200449), the valve cover, and the corrugated hose with the check valve at the turbo (essentially replacing your entire problematic PCV system) for less than $250-$260 brand new via amazon. That's cheap peace of mind, and hella cheaper than a failed turbo or constantly replacing your valve covers, which WILL continue to fail if that rubber piece is gone.
I have a thread that discusses my issues with the system which also links to everything to explain the PCV system (http://www.sonicownersforum.com/forum/1-4l-turbo-sonic-engine-discussion/23255-rough-idle-gear-while-stopped.html) because it's the one thing on this car that can stealthily cause many peoples issues (think lower mpg, inability to hold boost, failing valve covers, oil in charge pipes, rough idle).
Basically even with the orange rubber check valve there, once oil residue gets in there it's going to suffer in efficiency. This can happen at 1,000 miles, or 100,000 miles like in my case. It all depends on how you drive the car, and if it's tuned or not. It's a poorly designed system that needs to be maintained, but isn't mentioned to be maintained anywhere by GM.
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Yosemite Sam
I Hates Rabbits!
If you don't fix the intake check valve issue the PCV is going to blow again. Today I replaced my intake manifold with one that has the PCV fix (V1) on it and replaced the valve cover for the second time. Do yourself a favor and go back to the link to for the fix and order the new kit (V2). It comes with all the parts that you need and lists all the tools necessary to do it.
JTee2017
Well-known member
Read the Link in Pirate's thread below and related Cruze thread. . . . in detail. Very wise and detailed information you won't find anywhere else.
This compiled information . . AND the parts to be maintained are invaluable. Following *all* of the info in Pirate's thread and the Cruze thread will keep the 1.4L engine running.
Amazing what TWO little PCV check valves can cause in major engine damage if not maintained.
Just look at this as necessary maintenance. Some cars, especially higher end foreign cars, have more wearable items and costs than this by thousands of $$$.
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Pirate Luke
Member
I'm still working on organizing the information in my link (currently trying to make a simple visualization when I get time) as I too am still learning about this system. Now that I have a good grasp on it, it explains almost all my cars behaviors that I previously didn't understand.
For what it's worth, I implemented a modified version of the V2 kit from XtremeRevolutions cruze thread mentioned in Yosemite Sams post, and it has solved all of my issues while providing an externally maintainable PCV check valve. I bought a few of the V2 kits, and have an extra one if anyone wants to buy it off me. I think he sells the V2 kits for $85, and I can get it out for $75 shipped. Anyone interested or with questions feel free to PM me.
For what it's worth, I implemented a modified version of the V2 kit from XtremeRevolutions cruze thread mentioned in Yosemite Sams post, and it has solved all of my issues while providing an externally maintainable PCV check valve. I bought a few of the V2 kits, and have an extra one if anyone wants to buy it off me. I think he sells the V2 kits for $85, and I can get it out for $75 shipped. Anyone interested or with questions feel free to PM me.
shorebreeze
Member
I had a P0171 one time the first few months I had my Sonic, but this episode arose from a situation where the ECM had crashed due to a "bullet" style phone charger. Tossed the bullet, went to a conventional charger and have never had a recurrence--or another system crash. Which is a good thing because having the car behave momentarily like a computer was very disconcerting...I just had to coast to the side of the road and reboot, almost literally. The dealer warned me the next day about the issue with the charger.
the PCV Valve (Positive Crankcase Ventolition valve) is for situations where the crankcase has more air pressure that the outside valves. I all engines the rotation of the crankshaft churns up the oil causing it to foam and increasing the pressure in the crankcase. In worn engines cumbustion gasses may get into the crakcase (think worn rings.)
To aid in engine longevity maufactures put in an oil overflow pipe. To reduce the emissions of oil from car engines state and then the federal government required the use of the PCV valve.
To aid in engine longevity maufactures put in an oil overflow pipe. To reduce the emissions of oil from car engines state and then the federal government required the use of the PCV valve.
Yosemite Sam
I Hates Rabbits!
And that's why we no longer have breather tubes or caps on our engines.
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