2015 Silverado - Burning Oil (Active Fuel Management)

[Smith035]

Looking for some input on what everyone has done to try and stop burning so much oil?   I have a 2015 with about 75k miles on it. 

 

Changing the oil and going to do a consumption test over the next 3k miles but i am burning at least 2qrts every 3k.  

 

Who else has this issue and what side effects have you seen? Fouled Plugs etc....? 

 

Thanks. 

[Grumpy Bear]

It's hard to get your first post on such a 'hot button' responded to. 

 

What you are experiencing is ring coking. Oil has broken down to carbon and varnish and the rings are stuck in the ring lands. Yes I am assuming some thing like an otherwise mechanically sound motor.

 

Getting them unstuck is a trick. But that isn't what you're asking. 

 

I have a motor currently that has used up to a quart is 600 miles and yet ran pretty good. Never fouled a plug although the plugs looked bad. Never plugged an intake runner although there was allot of valve back side fouling. It just drank oil and started around, if memory serves, about 85K maybe a bit more. 

 

We have it down to about a quart in 10K now. 

Edited June 20, 2021 by Grumpy Bear

[pokismoki]

try adding a 1-2 quarts of ATF fluid to the crank case before every oil change, lots of detergents in that stuff.  I would let it run idle for 20 minutes at night, let it sit until the morning, run for another 10 minutes in the morning again, then drain, then get the cheapo synthetic oil case from Costco, run that stuff for 3000 miles, rinse, repeat , until it slows the consumption and cleans off the rings..

[pokismoki]

 

[DCazares]

I have the same problem,  burns 2 quarts every 3k miles. Currently at 95.5k miles. No other problems with it.

[KARNUT]

I had one small block Chevy that used oil. A 94 Z-28. I bought it used with 10K miles on it. GM said it was normal. Iv owned dozens of these small blocks. My wife put 60K miles on it. Then it was my son’s first car. Then it became my toy. I beat the dog out of it. Sold it to a friend for his son. With 140K miles on it. He wrecked it. Still using one qt every 2500 miles. Amsoil oil 20-50 once a year.

[DannyOB]

On 6/20/2021 at 6:29 PM, Grumpy Bear said:

It's hard to get your first post on such a 'hot button' responded to. 

 

What you are experiencing is ring coking. Oil has broken down to carbon and varnish and the rings are stuck in the ring lands. Yes I am assuming some thing like an otherwise mechanically sound motor.

 

Getting them unstuck is a trick. But that isn't what you're asking. 

 

I have a motor currently that has used up to a quart is 600 miles and yet ran pretty good. Never fouled a plug although the plugs looked bad. Never plugged an intake runner although there was allot of valve back side fouling. It just drank oil and started around, if memory serves, about 85K maybe a bit more. 

 

We have it down to about a quart in 10K now. 

So Grumpy Bear how do you free up the stuck ring. I’m going through 4-6 quarts every 10000 miles. Runs fine no smoke or leaks. 176,000 miles

[Grumpy Bear]

9 hours ago, DannyOB said:

So Grumpy Bear how do you free up the stuck ring. I’m going through 4-6 quarts every 10000 miles. Runs fine no smoke or leaks. 176,000 miles

 

Assuming the issue is a stuck ring? 

 

With patients and an ester-based engine cleaner. Currently I know of one. If the rings are truly worn out or bore worn out nothing short of a rebuild will work.

 

High Performance Lubricants SAE30 or 40-EC is what I used on my problem child mixed 4:1 to 5:1 with a HDEO with a good dose Mg and less Ca in the acid package. For me that was Shell Rotella T6 5W40. I buy this stuff by the case from Advanced Lubrication in Kankakee, Illinois. Early filter changes and often. 1,000 miles max first time. Judge from there but 2K was my limit. It may even get worse for a few OCI's. Took about 30K miles to get it under control. 

 

If you can get it to under a quart in 5K then switching to an ester containing oil will keep it clean. HPL or Red Line HP.

 

That soft sludge and varnish will come out pretty quickly, but the carbon takes tens of thousands of miles to solve out. 

 

We know have 225K on that problem child and it's doing quite well. A few ounces per 2K OCI. The pickup with the 4.3 is about a cup in 5K and has 175K on it. 

 

I can't see inside you motor so there are some IF's And's and Maybe's on the motors general condition. No way to walk back years of maintenance that led to this either. So, patients.   

Edited October 6, 2023 by Grumpy Bear