Air sucking on top of engine

[stever525]

I was checking out a rattle under my hood (loose coil cover) and I noticed air being sucked in through a vent(?) On the thing thing opposite the oil cap. I covered it with my finger and my engine started to sputter.

I'm just curious, but does anyone know what it is or why it does that?

(Reference picture)

 

[Chevrolet Customer Care]

stever525,

Let me know if you would like for me to have your Chevrolet dealership call in regard to this action. I am sure you will get some great input from the members as well.

Erica Tiffany
Chevrolet Customer Care

 

[Black Turbo LTZ]

I was checking out a rattle under my hood (loose coil cover) and I noticed air being sucked in through a vent(?) On the thing thing opposite the oil cap. I covered it with my finger and my engine started to sputter.

I'm just curious, but does anyone know what it is or why it does that?

(Reference picture)

If your talking about the "L" connector where 2 coolant lines go in it looks like your retaining pin is almost out, push it back in and see what happens. We took mine off when I added the temp adaptor fitting on my upper rad hose and when we reinstalled everything that part was making noise and to one point had a bit of coolant coming out, pushed the pin back in all the way and problem solved.

 

[ChrisJ]

If your talking about the "L" connector where 2 coolant lines go in it looks like your retaining pin is almost out, push it back in and see what happens. We took mine off when I added the temp adaptor fitting on my upper rad hose and when we reinstalled everything that part was making noise and to one point had a bit of coolant coming out, pushed the pin back in all the way and problem solved.

I think he's talking about the thing opposite of the oil cap, which would be the back of the valve cover I guess.

The coolant line certainly wouldn't be sucking air.

 

[River_Rat]

I think that is a pcv rupture disc. You should take it to the dealer and probably have your valve over replaced.


see also, http://www.sonicownersforum.com/for...ne-discussion/10825-1-4t-pcv-explained-4.html

 

[Black Turbo LTZ]

I think he's talking about the thing opposite of the oil cap, which would be the back of the valve cover I guess.

The coolant line certainly wouldn't be sucking air.

More than likely you are right...was hard to understand exactly where he meant.

 

[stever525]

After reading my original post, even I was kind of confused about what I was talking about. But yeah, River Rat understood. I'll have to have the dealer check it out.

Thanks guys.

 

[sx sonic]

Indeed it is the rupture disc for the PCV. If It's venting air It's blown.

 

[MikeM]

is this something that's hard to replace? im well out of warranty and my car started doing the same today?

 

[sx sonic]

is this something that's hard to replace? im well out of warranty and my car started doing the same today?

The valve cover is very easy to replace. We're talking 15 bolts that can be removed with a standard 12point socket, 2 torqs bolts, a connector, and moving a few wires out of the way.


Just to make sure, you're past 100k miles right? Some people aren't aware that the powertrain warranty is that long.

 

[meluskig]

The valve cover is very easy to replace. We're talking 15 bolts that can be removed with a standard 12point socket, 2 torqs bolts, a connector, and moving a few wires out of the way.


Just to make sure, you're past 100k miles right? Some people aren't aware that the powertrain warranty is that long.

This is covered under powertrain?!

 

[MikeM]

Yeah i didn't think about power train which i think it would be covered on. I made a appointment. I'm at like 80k miles on my 12.

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[MikeM]

Got my car back for this issue. Had 3 codes. P0171. P1101. P2270. They replaced the cam cover. Report said: cam cover leaking at pcv system. Now I don't have all that air sucking at that disc. Car runs fine. Covered under power train warranty. Thanks.

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[Paddy1337]

My Sonic has ran like crap since week 1, finally threw these four codes at 35,000 miles:
P1101
P0171
P013F
P0507

They replaced, my throttle body assembly. Also did some recall work, and a TON of issues I had with interior and exterior trim/chevy badge falling off the car.


told me it was ready today. I started the car, my seat cushion popped right back off when I sat down (I weigh 160lbs, not 300). While I looked around the interior the car was idling and threw a CEL again. Mind you, the idle is still a little rough like it's always been. I didn't have my code reader, but the service person said it had thrown 2 more P0171's.

Judging by all those codes, I'm not too sure the tech covered all his bases troubleshooting the car's issues. Though, who knows, the diagnostic machine may tell him exactly what to do with out him being allowed to think for himself.

Left the car there...

My money was on the front O2 sensor being bad, a cam position sensor being bad, and the spark plugs being poorly gapped form factory and/or ignition coil problems. But I don't have a fancy machine.

Edit: I also think PCV could be an issue, and worst case wastegate too

 

[ahtoxa]

Got my car back for this issue. Had 3 codes. P0171. P1101. P2270. They replaced the cam cover. Report said: cam cover leaking at pcv system. Now I don't have all that air sucking at that disc. Car runs fine. Covered under power train warranty. Thanks.

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Glad I found this! Mine is sucking air from that vent and I have a trip to leave for on Thursday.

 

[RichieRocket]

My disk burst too....

Add one more burst disk. I got the check engine light, rough idle, hesitation, code P0171. I was checking for cracked intake hose and heard the same camshaft cover sucking sound people described.

My 2012 1.4T is all stock, has 48K miles, dealer replaced the camshaft cover on powertrain warranty, runs fine now.

What is this disk for? I should have asked for the old camshaft cover to check it out...
Is it just a one way check valve so pressure doesn't build in the crankcase? Air should be exiting the engine thru the middle chamber of the intake manifold when on boost or off, as explained in the '1.4T PCV Explained' thread. I don't understand why air would need to escape here?

Has anyone seen or photographed the disk?

Rich

 

[Maddmatts]

It's a last line of defense should the PCV be unable to handle the volume of air passing through.

It seems like it was a mistake not making the disk a removable part from the valve cover. It's such an 80's level of waste to throw it away for such a little thing.

 

[RichieRocket]

It's a last line of defense should the PCV be unable to handle the volume of air passing through.

It seems like it was a mistake not making the disk a removable part from the valve cover. It's such an 80's level of waste to throw it away for such a little thing.

I figured it was a check valve allowing the air to flow out, only as a back-up. The PCV should not need a vent to the outside?!?
When my disk burst, the dealer could not get me in until the following Monday. So I thought I'd temporarily fix it with a piece of duct tape, folded over on itself at the part cover the little hole. So it still acted like a flapper, one way valve.
I started it up and it idled smooth, no hesitation. About a mile down the road, I stopped at a stop sign, took a turn and accelerated mildly, shifted to second and noticed a trail of white smoke behind me. Bummer!
So I pulled over and pulled the tape.

Why would oil get into the intake and cause smoke? Weird?

 

[ChrisJ]

I figured it was a check valve allowing the air to flow out, only as a back-up. The PCV should not need a vent to the outside?!?
When my disk burst, the dealer could not get me in until the following Monday. So I thought I'd temporarily fix it with a piece of duct tape, folded over on itself at the part cover the little hole. So it still acted like a flapper, one way valve.
I started it up and it idled smooth, no hesitation. About a mile down the road, I stopped at a stop sign, took a turn and accelerated mildly, shifted to second and noticed a trail of white smoke behind me. Bummer!
So I pulled over and pulled the tape.

Why would oil get into the intake and cause smoke? Weird?

White smoke is never oil, it's water. Grey\black smoke is fuel and blue smoke is oil.


You sure your exhaust wasn't just cold causing some condensing of gases in the pipe like normal?

If you want a temp fix, tape it completely, don't make a flap.

 

[RichieRocket]

White smoke is never oil, it's water. Grey\black smoke is fuel and blue smoke is oil.


You sure your exhaust wasn't just cold causing some condensing of gases in the pipe like normal?

If you want a temp fix, tape it completely, don't make a flap.

Sorry, I should have said grayish smoke, not steam/coolant. When I stopped, the cloud was all around the car, and I thought the smell was burnt oil. Now that you mentioned it, maybe it was running rich? For several days, the car was running lean at idle and low throttle, so the FI was dumping in more fuel. Once I sealed the little hole in the valve cover, the fuel trims had not had time to re-adjust yet? But it was a lot of smoke!

The air was getting sucked into the valve cover round part just behind the oil cap, so my crude flapper closed and sealed it when the engine was running. Not sure how taping it would make a difference? Both ways, outside air couldn't get in.

I should have asked for the old valve cover when they replaced it. Although on warranty, they probably wouldn't have given it to me...