6.2L - Debris Found in Engine Oil

[jbooose]

I have a 2021 GMC Yukon XL Denali with the 6.2L engine. For the first 3 years, all oil changes and maintenance was covered and performed by the dealer. Last year this maintenance ended and I personally did my first oil change on the truck at about 40K miles.

After I finished that oil change, I did another on a different vehicle which I no longer own. When draining the spent motor oil out of the drain pan I noticed some debris which remained in the bottom of the pan. I did not know which engine it came from as I had just changed oil from two different vehicles.

Fast forward a few months to this weekend and my Yukon now has about 45K miles on it and I just performed another oil change. I made sure to thoroughly clean the drain pan before I started draining the oil out of the engine. Sure enough, after I drained the spent oil out of the drain pan there were small bits of debris left in the drain pan. Some were actually rather large. The largest pieces I recovered from the spent oil were yellow, non-metallic, and somewhat brittle. The other debris found was a bit smaller and gray in color. All of the pieces seemed like they could be plastic as I was able to break them apart. Attached are a few pictures. I did not find any metallic looking bits in the oil but I did collect a sample and will mail it off tomorrow.

Any idea what this debris could be and how concerned should I be?

As a side note, when draining the spent oil back into the containers I wound up with about 6.25 quarts. The engine takes 8 quarts. I know some is obviously lost in the oil filter but I allowed that to drain upside for a while. There was not a low engine oil light on before the change. Unfortunately I did not check the oil level on the dipstick before the change. Is 1.5+ quarts of oil consumption normal for these engines over about 5K miles? For reference I am using Mobil 1 Advanced Fuel Economy Full Synthetic 0W-20 and a Wix filter

 

[Marky Dissod]

Is 1.5+ quarts of oil consumption normal for these engines over about 5K miles?

GM tests your sanity by saying '1qt per 1000 miles is normal' with a straight face, just to see if you'll fall for it.
Next time, try 4500 miles, see if the oil consumption goes down.
Find out which (Group4 synthetic) motor oil is spec-compatible with the 6.6L L8T, use that instead of 0W20.
Bet it's a 0W30 or 5W30, and that it'll consume less than a quart over 4500 miles.

 

[viven44]

Keep an eye on oil consumption and please report. You can pull out the dipstick in your usual parked position first thing in the morning before start and just keep doing it every 500-1000 miles, should know how much oil you are using.

Plastic debris ? Maybe timing chain guide?

 

[Blackcar]

I have a 2021 GMC Yukon XL Denali with the 6.2L engine. For the first 3 years, all oil changes and maintenance was covered and performed by the dealer. Last year this maintenance ended and I personally did my first oil change on the truck at about 40K miles.

After I finished that oil change, I did another on a different vehicle which I no longer own. When draining the spent motor oil out of the drain pan I noticed some debris which remained in the bottom of the pan. I did not know which engine it came from as I had just changed oil from two different vehicles.

Fast forward a few months to this weekend and my Yukon now has about 45K miles on it and I just performed another oil change. I made sure to thoroughly clean the drain pan before I started draining the oil out of the engine. Sure enough, after I drained the spent oil out of the drain pan there were small bits of debris left in the drain pan. Some were actually rather large. The largest pieces I recovered from the spent oil were yellow, non-metallic, and somewhat brittle. The other debris found was a bit smaller and gray in color. All of the pieces seemed like they could be plastic as I was able to break them apart. Attached are a few pictures. I did not find any metallic looking bits in the oil but I did collect a sample and will mail it off tomorrow.

View attachment 454350

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Any idea what this debris could be and how concerned should I be?

As a side note, when draining the spent oil back into the containers I wound up with about 6.25 quarts. The engine takes 8 quarts. I know some is obviously lost in the oil filter but I allowed that to drain upside for a while. There was not a low engine oil light on before the change. Unfortunately I did not check the oil level on the dipstick before the change. Is 1.5+ quarts of oil consumption normal for these engines over about 5K miles? For reference I am using Mobil 1 Advanced Fuel Economy Full Synthetic 0W-20 and a Wix filter

Wouldn't this vehicle be under power train warranty with milage and being a 21?

 

[jbooose]

Wouldn't this vehicle be under power train warranty with milage and being a 21?

You are right! Thank you for reminding me! It definitely is. I had completely forgotten about the separate powertrain warranty.

I just spoke to my service advisor and he is pretty stumped on where the debris could be from that was found in the oil. I am going to bring the filter in to him to take a look. Unfortunately he does not think GM will authorize any work without there being an obvious problem. Apparently debris in the oil is not an obvious problem. He did say that they could perform the next oil change themselves and look for similar debris. Finding debris on their own might allow them to do some sort of diagnostic work. We will see...

 

[Joseph Garcia]

Like @viven44 , my first thought was something related to the timing chain assembly.

 

[jfoj]

These engines take more than 8 qts with filter. Trust me, I have been round the block on this. I have a thread here where everyone roasted me, I do not care, I matched the factory fill level and have just recently check 2 differnet 2025 6.2l that were delivered and the level was the same as I found on mine, slightly above the top hash marks. Do what you want, but oil is what keeps these engines together. I run 9 quarts when I change the filter. This matched or was just ever so slightly above the factory fill level. 8 Quarts probably is about 1/3 up the has marks on your dipstick.

The low oil light does not come on until the engine is at least 2 quarts low on oil, probably more if you are running 9 quarts.

If you like your vehicle and want to keep it, check the oil every 2nd fill up and ditch the 0W20 oil. Run a decent 5W30 or 0W40. 0W40 is recommended in a number of the GM cars with the same basic engine and also when "Tracking" them, but then they say immediately change to 0W20 when you are back on the street for some that recommend 0W40 for the track. It is not for the engine health, it is for CAFE/Fuel Economy reasons and GM cannot tell you to run something else otherwise they risk fines.

Get a magnetic drain plug, M12 x 1.75. Save your oil filters and cut them open, send oil samples to the lab if you are curious/worried, change the oil when the OLM hits 50%.

I just did my 3rd oil change on my truck yesterday at 5900 miles.

 

[West 1]

Dont get over excited about adding extra oil. When over filled the crankshaft starts stirring the oil into a mess of oil and air. On a dyno they can test engine performance, add an extra quart of oil and watch the horsepower start falling off. There is a reason for factory fill recomendations.

As far as the Dealer saying Trust Me, we will change it and determine the issue. I would want to be there and witness the oil drain and inspection. Just to make sure nothing is swept under the rug. The plastic is probably from a timing chain tensioner failing. They know this also but their goal is to get you past warranty while your goal is to have a good engine long term.

 

[JKeller]

Agree with the others on both accounts: 1) My experience with my last two Tahoes has been the oil consumption stops (or drastically decreases) when going to a 30 weight oil; and, 2) I would be documenting the heck out of the pieces you are finding in your oil and would make sure the dealership finds them too and takes appropriate action. I know some have said some dealerships just want to get the vehicle through warranty and that's true, but I've also come across dealerships that are happy to have warranty work to do that they can bill GM for.

 

[jfoj]

Dont get over excited about adding extra oil. When over filled the crankshaft starts stirring the oil into a mess of oil and air. On a dyno they can test engine performance, add an extra quart of oil and watch the horsepower start falling off. There is a reason for factory fill recomendations.

As far as the Dealer saying Trust Me, we will change it and determine the issue. I would want to be there and witness the oil drain and inspection. Just to make sure nothing is swept under the rug. The plastic is probably from a timing chain tensioner failing. They know this also but their goal is to get you past warranty while your goal is to have a good engine long term.

@West 1

I clearly understand if you overfill the crankcase drastically you can have the crankshaft start to foam the oil and this will cause problems.

BUT understand, and this is what everyone does, they do not think about what I have posted or what we are talking about here.

I am not overfilling the crankcase by 1-2 quarts of oil. Funny how many years ago the V8 engines were speced by GM to run 8.5 quarts of oil with filter change. Then GM got tired of listening to everyone complain that shops were charging for 9 quarts of oil and not using it all, so GM with the release of a document and no other changes to the prior or future engines indicated the V8s from the day the document was released would no longer required 8.5 quarts with filter, but 8.0 quarts with filter.

A number of observant people have done what I did and check the factory oil fill and also determine how much oil is required to hit the top line on the dipstick above the hash marks and the concensus is these engines require 8.7 quarts with filter change. In general the factory oil fill appears to be slightly above the top line above the hash marks on the dipstick as well.

So based on this at worst case the engine may be overfilled by a approximately 9.6 ounces. Then pay attention to the size of the oil pan, at most we are talks probably less than 1/4" total increase in oil level height and it is probably less than 1/8". There is plenty of space between the windage tray and the oil level to not cause probems. I have been running 9 qts for the past 6k miles and there have been no problems, I have checked the oil level both cold and after driving 6 hours to inspect for any aeration or foaming problems and there are none.

The irony is most of all the V8 engine failures are clearly oil related. Most likely due to chronically running these engines low on oil which probably leads to increase oil temperatures and oil starvation to the main and rod bearings. There are likely other contributing factors to these engines failures that are more based on useage as well. Not going to to into these, but with the larger oil sumps on these engines, it takes 20-30 minutes for the oil to fully warm up when driving.

Back to the original posters question about debris in the oil pan, I would bag what you have and put the date and mileage on what you found. Wise idea to actuallly have a clean drain pan to look for debris and such when changing oil. You might want to consider running an oil analysis on your next few oil changes to see if you have any high wear metals as well. I would also probalby write an email to the dealership Service Manager to include pictures and the description of what you found. Specifically ask for a response, inquire whether they have seen similar things in the past, do they have any specific recommendations as to what action you or the dealer should take. Then hopefully you have a "documented" exchange about this issue in case you have some sort of catastophic problem beyond the powertrain warranty. This may help your case if you do have some future failure.