# Oil in spark plug well and engine misfires



## sklemetti (Dec 18, 2019)

This morning I made a couple of stops. Then I started my 2012 Cruze LS 6 speed with 216,200 miles and the Stabilitrak light came on and the service message. Then the engine light came on. And the engine was running rough. I could get it to 55 but with much time and vibration.

When I got home I checked on the ignition and spark plugs. The #2 and #3 spark plug wells were full of oil. The boots of both were caught in the well when I pulled the coils up.
And both the plastic in #2 & #3 were broken in the same manner as shown in the photo.

I cleaned the oil out of the wells and the boots and got new spark plugs as I have not replaced the originals. I put it back together and it runs rough but ok at 55 MPH. I'm wondering what caused the oil to get in the wells, the plastic to break and what will fix the misfires. I'd have to replace the coil assembly. And why is the Stabilitrak erroring too.


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## plano-doug (Jul 1, 2015)

sklemetti said:


> This morning I made a couple of stops. Then I started my 2012 Cruze LS 6 speed with 216,200 miles and the Stabilitrak light came on and the service message. Then the engine light came on. And the engine was running rough. I could get it to 55 but with much time and vibration.
> <snip>


If the engine is not running right, the computer disables Stabilitrak. Hence, the light.

The oil shorted out the two plugs causing the misfire, and likely killing the coil pack. And causing the check engine light. 

The oil comes from a leaking valve cover gasket. On the 1.8L motor in the LS, that is not too bad a repair: ~40 bucks for the gasket plus a couple hours in the driveway.

So fix the gasket, and replace the coil pack (aka ignition coil module). Maybe do the spark plugs while you're at it.

I should add, this is the most likely scenario. There's always a chance something else could be wonky, but in my personal experience, it was the valve cover gasket.

Doug

.


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## sklemetti (Dec 18, 2019)

Today I went to Autozone and got the valve cover gasket ($48) and the ignition coil ($120) and it comes with a lifetime warranty. I get get to the point of taking the valve cover off and I see it has starhead bolts. So I have to go back to Autozone and get a torx socket set for them. While there I had the guy run the diagnostic on the check engine light and he said the #4 cylinder was misfiring. But it was the #2 & #3 that had leaked oil and the coil was broke. 

I get home and take the cover off and put the new valve cover gasket on and then put the cover back on. On doing a final tightning, I overtorqued a bolt and the head came off. Good thing it was tight as I won't have a need to remove the cover again. I put the ignition module in and with the new plugs it runs as good as new. The Stabilitrak light was not on. The engine light was on for about a half hour than went off.

Thanks for the diagnostic and instructions.


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