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2012 LT - with oil consumption, cracked #7 plug and now fouling #1 plug

ltklein

Full Member
Joined
Mar 3, 2005
Messages
54
Location
Hades, Aridzona
So....I have had this 2012 Avalanche since new (2nd one).  It's now at 86,000 miles.

I'm having the same symptoms that are regularly reported for 2011 and earlier Avalanches, however the TSB for this issues ends with early 2011's.

Now the story...

Last summer had a misfire in #7.  Pulled the plug and half the porcelain was missing. Looked into the cylinder...all looked good.  Replaced the plug and life was good.

At this point I was oblivious to this being a chronic issue with AFM engines.

Over Christmas, replaced all plugs - including #7.  All plugs looked great except for #1 which was oil fouled around the base.

Still oblivious to the TSB, I elected to pull that plug again in a few months and see if it's still an issue.

So, here we are now... pulled #1 and it's oil fouled.

Pulled the left valve cover last night to see if it is the correct one that's supposed to fix these issues.  It is...

NOT pulling oil pan to see if the spray deflector is installed there...that issue allegedly was corrected starting int he 2010 model year so I have to assume it's in my engine.

I have an exact set of issues that match the TSB, but apparently the fixes are built into my motor.

The only step I feel I have is to get the **super expensive ($90!!!)** top engine cleaner recommended by the TSB, and put the 4.5 ounces in each cylinder for 2.5 hours and see if that frees up the oil ring in Cylinder 1.  The only other thing I've seen done is a factory replacement of rings and pistons.

Being 8 years old I'm clearly out of warranty. 

Has anyone else with a 2012 or 13 seen these symptoms?  I only found one on the web and he got an engine replacement paid for by GM.

Any other thoughts on this?  Engine is way too young for this type of issue!....
 
One item in my subject line - oil consumption...

It's not huge but I learned back around 40K miles that i had to check my oil 2 -3 times between oil changes or it will go dry.  I understand the spec is it's excessive if it's losing a quart every 2000-3000 miles.

That's been easy to keep up with but this is the first vehicle I've owned since 1996 where I must check my oil between changes (good practice vs. MUST).

So that's the 3rd leg of the TSB....  oil consumption and fouling of 1 and/or 7 or cracking of 1 or 7.

3 reasonably rare issues all appearing on the same engine, but all featured in a TSB...

 
So....I have had this 2012 Avalanche since new (2nd one). It's now at 86,000 miles.

I'm having the same symptoms that are regularly reported for 2011 and earlier Avalanches, however the TSB for this issues ends with early 2011's.

Now the story...

Last summer had a misfire in #7. Pulled the plug and half the porcelain was missing. Looked into the cylinder...all looked good. Replaced the plug and life was good.

At this point I was oblivious to this being a chronic issue with AFM engines.

Over Christmas, replaced all plugs - including #7. All plugs looked great except for #1 which was oil fouled around the base.

Still oblivious to the TSB, I elected to pull that plug again in a few months and see if it's still an issue.

So, here we are now... pulled #1 and it's oil fouled.

Pulled the left valve cover last night to see if it is the correct one that's supposed to fix these issues. It is...

NOT pulling oil pan to see if the spray deflector is installed there...that issue allegedly was corrected starting int he 2010 model year so I have to assume it's in my engine.

I have an exact set of issues that match the TSB, but apparently the fixes are built into my motor.

The only step I feel I have is to get the **super expensive ($90!!!)** top engine cleaner recommended by the TSB, and put the 4.5 ounces in each cylinder for 2.5 hours and see if that frees up the oil ring in Cylinder 1. The only other thing I've seen done is a factory replacement of rings and pistons.

Being 8 years old I'm clearly out of warranty.

Has anyone else with a 2012 or 13 seen these symptoms? I only found one on the web and he got an engine replacement paid for by GM.

Any other thoughts on this? Engine is way too young for this type of issue!....
I'm having the exact same issue with my 2012 avalanche, #1 plug oil fouling, rough idle,occasionally give misfire code. Help
 
I'm having the same oil consumption issues, as well as fouling in #1 spark plug. I purchased the Range Tech AFM disable chip, which has helped prevent the oil consumption greatly, but it still has issues, and occasionally I get low oil pressure requiring an immediate oil and filter change. I was just told by an experienced mechanic that the AFM oil consumption issues are due to a faulty O-rings in the VLOM. Also the screen in the VLOM where the pressure sensor in connected is what fouls and causes the low oil pressure light. According to Bill, when the O-rings start to leak by, oil get into places it shouldn't, causing the flow to get into the cylinders. I plan to replace the VLOM in the next week or two. I will advise on my results. (Rock Auto has an "improved design" VLOM from Dorman for $170). Just replacing the screen will help if you only get low oil pressure issues.
 
Last edited:
Please see my post about this. I started a new thread concerning oil consumption, AFM, etc.
 
Keep in mind, while the AFM system can cause oil to leak, if you're getting misfire codes as well you might have piston rings failing on you. Which will also let oil into the cylinder but also cause reduced power output from that cylinder. Just another thing to look at.
 
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