# 2013 1.8 LUW misfire diagnosis



## plano-doug (Jul 1, 2015)

2013 1.8 LUW misfire diagnosis

Last night, my wife called me complaining of shaking, with no acceleration, SERVICE TRACTION CONTROL and SERVICE STABILITRAK lights/messages, and the check engine light flashing. She did manage to drive the car the few miles to the house.

My scanner showed a P0303, which explains the shaking and the flashing CEL. 

This morning, I removed the coil packs (not sure what that brick is called) and found oil in the #3 plug well. 

So I'm thinking valve cover gasket. I'm on my way to Autozone to get a new one. In the mean time, I ask if y'all agree with that, and what tips, comments and suggestions you may have. TIA.

(BTW, I love how Mahle refers to their replacement as "MAHLE Original(R) gaskets" without actually saying they are OEM. I'm getting the Fel-Pro - it's in stock.) 

Doug

.


----------



## plano-doug (Jul 1, 2015)

Here's a pic of the top of the head. There are two conflicts I'm trying to resolve.

There appears to be a tiny bit of RTV where the elevation changes. I plan to put some there even tho the Haynes does not mention it. But from what I've seen with other gaskets, this type of thing would typically get some RTV.

The Haynes does say to "apply sealant to the center bolt at the right end of the engine (next to the timing belt cover)". I see no signs of any sealant having been here. 

For now, my plan is to add a tiny bit of RTV to the two spots indicated in the pic, but forego any sealant on the center bolt since there was none before.

If someone has input on this, please let me know  

BTW, the rings in the gasket around the plug well openings were very hard compared to the other sections of the gasket, which were more rubbery. I assume the heat around the plug openings has caused the rubber to get hard there. And that is likely why it began leaking.

Doug



.


----------



## plano-doug (Jul 1, 2015)

Here's a pic of the finished valve cover. I used the Fel-Pro VS50779R gasket, 46 bucks plus tax from Autozone. I cleaned the cover as best I could while I had it off. It looks a lot better here. Alas, with the oil leak fixed and all the oil cleaned off coil #3 of the ignition coil module, I still had a pretty bad misfire 

After pondering it a while, I decided that the oil leak probably hadn't been completely shorting out the coil, but instead had been drawing excess current which ultimately killed the coil over a period of time. I took it over the Autozone and the manager and I put a meter on it. Most of the connections checked good, but when I probed between B+ (pin A) and the spark plug contacts, plugs 1, 2 and 4 showed about 14k-ohms, but plug 3 showed only 2k-ohms. I was satisfied that confirmed that coil #3 was bad and hence the cause of the P0303.

I bought the Duralast (Autozone store brand) ICM , p/n C1646, for about 113 dollars plus tax. I would have preferred an AC-Delco or maybe a Delphi, but there were none of those at this store or any others in nearby suburbs. The Duralast was all that was available without waiting a day or two to get a different brand delivered. The nearby O-Reilly's only had their store brand in stock as well.

So I took the Duralast and installed it in the car and cranked her up - she was purring like a kitten again  

I also fixed my intake manifold tuning issue while I was at it. Here's a write-up: https://www.cruzetalk.com/forum/9-general-discussion/51273-p2076-imt-code.html#post3237073

With the mis-fire gone and the throttle response restored with the IMT fix, it's driving like a new car now 

I am perturbed at having to buy a 4-coil module when only one coil was bad. I suppose that makes it easier during assembly at the factory - less labor to install a four-coil module than four one-coil modules - but it sucks paying for four when only one is dead 

Lastly, the plastic panel bearing the bow tie and "Ecotec" doesn't fit snugly in place - it rattles quite a bit - which is not something you want to hear coming from under the hood  While I was at it, I re-loomed a section of harness going to the front cam actuator, and I zip-tied it in place. The free end of the zip tie was wedged into the gap by the rattling panel which pretty much killed all the rattling  

Doug

.


----------



## Ma v e n (Oct 8, 2018)

I do like to put RTV at interfaces like that, and I do put teflon paste pipe sealant on the center bolt as well(that's the recommended sealant) the original bolts have microencapsulated sealant on them I believe.


----------



## plano-doug (Jul 1, 2015)

Ma v e n said:


> I do like to put RTV at interfaces like that, and I do put teflon paste pipe sealant on the center bolt as well(that's the recommended sealant) the original bolts have microencapsulated sealant on them I believe.


Thanks, Maven. 

You put it the teflon paste on the threads? I can pick some up and add that without much trouble. 

Doug

.


----------

