LML Dirty oil 300-400 miles after dealer service

2012 DMAX

Member
Nov 4, 2012
41
0
6
Southwest IA
Last September I took my 2012 Silverado Duramax to the dealer where I bought it. It was due for engine oil and filter and fuel filter before we pulled the camper on a trip to the Grand Canyon. Checking the engine oil in KS or CO I notice it's pretty dark already... dark enough you can't see through it and make me wonder about the dealer. Is this normal or did they not let it drain completely or ??? I told them to change oil AND filter.
 

Novak

SQUIRREL TRYN TO GET A NUT
Jun 15, 2015
990
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16
Cloud 9, IDAHO
I’ve seen regen cycles darken oil fairly quickly. No exact time frame as far as mileage but within a regen or two.


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Vmyrhaug

2003 lb7sac45 35" 20x12 fjallasport flares
Mar 6, 2016
177
6
18
41
Norway
Its a diesel engine.. oil will be dark and sometime black right after oil change. That normal.
 

Ne-max

I like turtles
Nov 15, 2011
3,361
64
48
Lincoln, Ne
I only see LB7s with clean oil. 04.5 and newer always turn black within 500 miles. Even deleted ones.
 

2012 DMAX

Member
Nov 4, 2012
41
0
6
Southwest IA
OK great. Thank you both.



How about oil change intervals... do you folks use the computer's recommendation for oil life remaining ? I'm old school when we used to change oil and filter every 2000 miles. But I understand the newer oils and filters have improved.
 

Novak

SQUIRREL TRYN TO GET A NUT
Jun 15, 2015
990
0
16
Cloud 9, IDAHO
OK great. Thank you both.



How about oil change intervals... do you folks use the computer's recommendation for oil life remaining ? I'm old school when we used to change oil and filter every 2000 miles. But I understand the newer oils and filters have improved.



Oh god here we go! Everyone has different opinions. Personally on my deleted LMM I ran 10k oil changes and 5k filter changes no problem for years. On a emissions intact vehicle I wouldn’t push over 8k and 4K filter swaps on the best oil just because the abuse it sees during the regen process. Schaeffers is all I would run because it’s great oil, and they give you free oil sample kits every time you going in for more oil.
Fleetguard filter or AC Delco, you can find them on Amazon for dirt cheap.


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Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,644
5,785
113
Phoenix Az
All I’ll say is you can’t change oil too often but you can change it too late.
 

CDmax16

Member
Mar 3, 2018
63
11
8
55
NNV
Part of the problem can be the factory oil pan leaves about 3/4 of quart of old oil in it. After I put a PPE pan on, my Schaeffer’s looks better at a couple thousand miles than it did after a couple of days in the stock pan.
 

Hambone

Always learning
Jan 24, 2016
572
0
16
Florida
We try to not exceed 5k on our fleet
The old LBZ’s would be pretty black at 5k and 8k was border line sludge lol
That’s deleted- PCV rerouted eGR blocked pulling trailers and just abusing them!
My Lly oil at 5k is almost clean
The new L5p’s at 5k is so black if you get it on you it stains your skin bad :(
Now I wear gloves and long sleeve when changing the newer stuff
Btw 10k on fuel filters;)
 

Hambone

Always learning
Jan 24, 2016
572
0
16
Florida
Also should add that dirty oil isn’t necessarily a bad thing... just means it’s doing it’s job and cleaning
 

2012 DMAX

Member
Nov 4, 2012
41
0
6
Southwest IA
Thanks for all the replies, didn't mean to derail my original topic but always looking for opinions on oil/service and this diesel pickup subject that is relatively new to me.
 

OregonDMAX

NOT IN OREGON, NO DURAMAX
Apr 28, 2013
3,964
8
38
36
Goodyear, AZ
Follow the dic and change it at 20% is what alot of dealers are saying

I don't look at the oil it's not going to tell you what you need to know just by color. My lb7 would always stay pretty clean even after a few thousand. Now since the external cooler adding 4 extra quarts I can't get the oil out so it's dirty 3 seconds after startup. But I've always changed my oil at 2k miles
 
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Dozerboy

Well-known member
Jun 23, 2009
4,892
470
83
TX of course
I got used oil analysis on my truck the show the oil is fine up to 16k miles on Dino oil.

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Robby Avery

GM TECH @ FENDER GMC
Jul 31, 2008
820
2
18
Norman Park, Georgia
Funny thing here is the 2 cups of oil left in the stock lower oil pan hasn't been mentioned. the 2 cups of dirty oil can make a fresh oil change look as though it wasn't even performed:thumb:
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,724
292
83
Boise, ID, USA
On my stock (tune only) LB7 in the Suburban, I change it around 10-12k miles without issue. Since building the LB7 in my truck I do 5k changes, but might start working that up to 10k soon. This is on dyno oil with ACDelco filter, and I change the filter with the oil.

In my opinion there's no reason to go less than 5k miles on a change, you're just wasting money. At least on a stock motor.

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Ne-max

I like turtles
Nov 15, 2011
3,361
64
48
Lincoln, Ne
Funny thing here is the 2 cups of oil left in the stock lower oil pan hasn't been mentioned. the 2 cups of dirty oil can make a fresh oil change look as though it wasn't even performed:thumb:

And another quart in the oil cooler, oil lines and block