Rough idle, what should I checkout myself first?

[leaky]

Hi,

I've got a 2012 with the 1.4T, has 92K on it.

Was good up until now (no breakdowns, just oil changes and topping off fluids), however yesterday I noticed a bumping sensation at idle (like you were sitting on a bridge and trucks were going by), which is not due to the AC.. Opening in the hood reveals indeed it's idling rough, a sort of miss or surge at low RPM that makes the engine vibrate a little. Check engine light then came on an hour after noticing this, checked engine - is still there and has oil in it.

I called the dealer and apparently they are so backed up they can't look at the car until June 10th. They say this is happening in the area at all dealers due to summertime driving habits, ie cars coming out of storage, spring tire changes.. Whatever, I can use my old truck or borrow one of a couple vehicles, in the meantime though thinking maybe I should check a few things?

Theoretically the car is on powertrain warranty but I know that's not covering some things - going to have the codes read later today and start there.. Any common non-warranty issues I should think about correcting in the meantime? Anyone get burnt by a non-warranty issue like this?

I literally never bring a vehicle into the dealer except to get warranty work done, it's all DIY or if I don't have the time I use local shops where folks I know do it for less, paying them in cash, hunting down parts at a discount, etc.. etc..

Thanks,

Jon

 

[Natesriv]

check for a vacuum leak (hear any hissing?)

A coil pack could be going bad too. #1, go to a auto parts store and have them read the code to you. That's the 1st step in solving it

 

[Natesriv]

Also refer to your manual, you're getting really close to the 100K service interval, the manual calls out all the areas to check/replace.

 

[leaky]

Thanks guys -

Going to my friends shop later today to have them pull codes and see what they think. If there are some service interval items likely to blame will go ahead and do them.

Basically anything I end needing to pay for at the dealer anyway may as well do it now and cheap given the dealer won't even see it until later in June.

Jon

 

[leaky]

Looking at the service intervals, the only thing I come up with that hasn't been done and could in any way be related is spark plugs.

They are probably worth changing. Might just do that today; I don't expect it to help but can't hurt.

Jon

 

[Papasonic]

When you remove the coil pack to access the spark plugs, inspect the connection between each plug terminal and the coil. Make sure the connection is solid, and there is no evidence of arcing or deterioration where the plug connects with the coil.
When my 1.4 was almost new, I had a coil pack failure, causing a rough idle and CEL illumination. There was no coil output to #4 cylinder, causing the misfire.
I had to have the coil pack replaced to resolve the issue.

 

[leaky]

Pvc

Has 4 codes, p0171, p0106, p1101, p0300. a lean, airflow, misfire, and another.

A minute or two of trouble-shooting reveals the engine runs right upon removal of the dipstick and there is a hiss out of the PVC valve. Seems to be the PVC valve (which is really part of the valve cover) has gone.

Can anyone confirm this is a 100K warranty part?

Thanks,

Jon

 

[Natesriv]

is that valve replaceable, if so it's far quicker to DIY...most PCV valves are just pop on, pop off

 

[leaky]

is that valve replaceable, if so it's far quicker to DIY...most PCV valves are just pop on, pop off

It's not rather it's part of the valve cover - you need to take out about a dozen bolts and move some other odds and ends around. Part is about $75.

For the cost of fuel I'm burning driving the Avalanche to work it would still be cheaper to replace the valve myself though, and certainly could DIY - just haven't had the time.

Jon

 

[kevjam79]

This is a known issue with the 1.4t and is covered under warranty. They will need to replace the valve cover w the integrated PCV valve and likely the wastegate actuator pin for underboosting.

While they are in there, I would have them replace the spark plugs. Make sure that they check the gap. There are known gapping issues with this plug from the factory.

Are you running a synthetic oil? I would recommend switching to Mobil 1 Extended Performance. It will keep the orfices clean and prolong the life of the PCV valve and turbo.

Good luck!


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[ChrisJ]

Not sure if it was said or not, but the 1.4 calls for having the spark plugs changed at 60,000 not 100,000.

I'm at 62K and need to do mine, I keep putting it off.

 

[totino's]

I just had my valve cover replaced by the dealership. It was no charge for the replacement. So I assume its covered under the power train warranty and my extended warranty has a $200 deductable. They even gave me a loaner car because they had to order a part.

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[kevjam79]

It is covered under the factory powertrain. The loaner car shows how serious this is. Most dealers will not give a loaner unless it is a fatal flaw. I hope others are watching for the signs of this failure.


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[Chevrolet Customer Care]

I just had my valve cover replaced by the dealership. It was no charge for the replacement. So I assume its covered under the power train warranty and my extended warranty has a $200 deductable. They even gave me a loaner car because they had to order a part.

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Glad to hear everything worked out, totino's! If you ever have questions we're here to help. Enjoy the rest of your weekend!

Amber N.
Chevrolet Customer Care

 

[totino's]

Glad to hear everything worked out, totino's! If you ever have questions we're here to help. Enjoy the rest of your weekend!

Amber N.
Chevrolet Customer Care

Thank you!

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[sdgdf]

I'm reviving this thread.

I just recently had the valve cover go out on mine. Hissing noise from the pcv. Only had code P1101.

Changed the valve cover. No more hissing from the pcv, no more code P1101, though now it has codes P0300 and P0106. Checked the coilpack and I can't get it to seat any better. There's also a hissing noise further back towards the firewall. Is my intake manifold bad?

 

[TboneMinister]

I'm reviving this thread.

I just recently had the valve cover go out on mine. Hissing noise from the pcv. Only had code P1101.

Changed the valve cover. No more hissing from the pcv, no more code P1101, though now it has codes P0300 and P0106. Checked the coilpack and I can't get it to seat any better. There's also a hissing noise further back towards the firewall. Is my intake manifold bad?

It was likely the PCV in the intake manifold that failed, which can also cause the failure of the PCV Valve Diaphragm. If you only replaced the valve cover, you may have only fixed half of the issue.

 

[sdgdf]

It was likely the PCV in the intake manifold that failed, which can also cause the failure of the PCV Valve Diaphragm. If you only replaced the valve cover, you may have only fixed half of the issue.

Does that also lead to a massive vacuum leak? Checked yesterday and it idles correctly with the MAF unplugged. There's a whistling noise that changes with RPM coming from the intake manifold.

Does anyone here have experience with the intake manifold kits on the Cruzetalk forum?

 

[gnonne]

How many miles on your 2012?

Steps look pretty easy now that he has a V3 kit where you do not need to remove the intake. For $5 extra you get a bit of extra small hose and clamps so you don't even need a heat gun.

I was going to do my 2013 as preventative (it has 24k miles.) I checked the orange valve and it was in tact, I have no codes, the car runs well, then my basement flooded... Some things take priority.

If you have a lot of miles, maybe the PCV fix is a priority for you.

 

[sdgdf]

How many miles on your 2012?

Steps look pretty easy now that he has a V3 kit where you do not need to remove the intake. For $5 extra you get a bit of extra small hose and clamps so you don't even need a heat gun.

I was going to do my 2013 as preventative (it has 24k miles.) I checked the orange valve and it was in tact, I have no codes, the car runs well, then my basement flooded... Some things take priority.

If you have a lot of miles, maybe the PCV fix is a priority for you.

It has 120k on it, I tried checking for the orange valve and everything was dirty and couldn't see it, after cleaning it its not visible so I guess its gone.

The V3 kit looks good but I'm not sure how hard it'll be to get that grommet secured in there with epoxy.