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Normal oil consumption raises concern for Duramax diesel engine

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An accepted rate of oil usage is sparking concerns from owners for the General Motors 3.0-liter Duramax diesel engines, leading to much debate on what to do about it.

The GM 3.0-liter Duramax diesel engine is a turbocharged inline 6, and it’s now in its second generation, known behind the scenes as the LZ0 Duramax diesel. It is used in the 2023 Chevy Silverado 1500 and the 2023 GMC Sierra 1500. The prior generation LM2 Duramax diesel is available in the GMC Yukon, Chevy Tahoe and Cadillac Escalade.

What is normal oil consumption?

An issue raised by owners on various forums has been about oil consumption. Many owners are fuming over the idea that an engine is designed to use oil, the amount of oil used and that this is part of the normal operation of the engine.

In the minds of these owners, engines shouldn’t use any oil. If they do, that’s a knock against it for reliability, and it is an engineering failure.

However, GM says there is such a thing as normal oil consumption, and it will appear in two different ways.

First, the factory puts in extra oil as part of the production process for the LZ0 Duramax engine.

“The 2023 LZ0-powered vehicles are shipped with an extra quart of oil in the crankcase,” said Sean Szymkowski, senior manager for Chevrolet Trucks Communications. “This extra oil is only required for the first factory fill. At the first oil change, the standard oil amount is used moving forward. Chevrolet dealers have been advised of this.”

Dealers have also been made aware of normal oil consumption through a technical service bulletin #21-NA-272 issued in November, 2021 advising them of this concern if raised by an owner for the LM2 Duramax diesel. Symkowski confirmed this also applies to the LZ0 Duramax diesel as well.

The service bulletin says: “The accepted rate of oil consumption for engines used in the vehicles referenced is 0.946 liter (1 quart) in 3,200 KM (2,000 miles).”

This rate only applies to personal use vehicles, under warranty, that are driven in a non-aggressive manner and maintained in accordance with the appropriate maintenance schedule or driven at legal speeds in an unloaded (for trucks) condition.

This rate does not apply to vehicles that are driven in an aggressive manner, at high RPM, high speeds or in a loaded condition (for trucks). Oil consumption for vehicles driven under these conditions will be more and accepted rate is 0.946 liter (1 quart) in 1,600 km (1,000 miles).”

Is oil consumption for GM 3.0L Duramax diesel engines bad?

Engines using oil is a bad thing, right? Not really.

Many pieces of equipment use oil, and it is actually more common than one would think.

The fact is owners should always be mindful of their oil levels in their trucks, and this especially applies when towing or hauling consistently. A truck is simply a much larger tool, and it requires maintenance as well as keeping an eye on fuel, oil and other fluids to operate correctly.

Aftermarket to the rescue!

An option for those who are concerned about oil consumption would be to look to the aftermarket.

For example, quite literally in the same time frame of researching this story, PPE reached out with an offer to use their oil pan, which allows for an additional 2 quarts of oil in the truck.

PPE says this helps “stabilize” the oil consumption concern by allowing you to simply have more oil in the crankcase.

I figure a little extra oil can’t hurt, so I plan to install it on the 2023 Chevy Silverado 1500 with the Duramax diesel I bought for a long-term review vehicle.

The bottom line

If you are an owner who keeps a tedious watch on their truck and doesn’t want any oil to be lost, well, then, you are going to have a hard time with this issue. However, if you see oil consumption as normal, like GM engineers do, then this is much ado about nothing.

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Tim Esterdahl

Automotive Journalist Tim Esterdahl has been a lover of trucks and SUVs for years. He has covered the industry since 2011 and has pieces in many national magazines and newspapers. In his spare time, he is often found tinkering on his '62 C10 pickup, playing golf, going hunting and hanging out with his wife and kids in Nebraska.

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3 Comments

  1. Steve Pratt January 25, 2023

    Hey Tim,
    I’ve been thinking about this since you posted your video on YouTube last week. Oil consumption has come up over the years on a number of vehicles and it often gets a bit contentious.
    It might make more sense if you specify what you mean by “normal”. Normal can refer to design expectations, average consumption for engines running normally, amount of oil burning that damages other systems (catalytic converters), etc.
    In this case, I think you are really talking about the amount of oil consumption at which GM believes it is compelled to provide a correction (which considering the possible fixes, could be quite expensive for them). Which is why they used the term “accepted” consumption rather than “normal”. I would bet you that the engineers do not believe that an LM2 or LZ0 in normal condition and normal operation is going to burn a quart of oil every 1000 miles, just that if one did, they would recommend rebuilding or replacing the engine.
    By the way, I bought a Sierra 1500 with the 3L Duramax last year, largely based on your initial impressions. I am thoroughly pleased with it. And after 20,000 miles, my oil consumption to date is… zero quarts.

    Reply
    1. Anonymous January 28, 2023

      I have a 2023 GMC SIERRA SLT with the LZ0 and have about 1200 miles on the engine. I check my oil level and the oil color routinely and can say that my oil level is the same as when I first bought it. The oil color has darkened a bit but not appreciably.

      Reply
  2. John February 7, 2023

    Hi there, I ran into this issue with a Subaru Forester a while back. It was the same song and dance with the Subaru dealer. At first, it was “normal”, then it was “our acceptable usage is XXX quarts per XXX miles…” which lead to an oil consumption test, and after that Subaru finally started fixing the issue. They never acknowledged that there was in fact an issue, but it had something to do with the cylinders or something becoming warped. It was no small feat to correct the problem which is why I suspect Subaru was reluctant to fix the issue, and to my knowledge, never officially acknowledged there was an issue. It required the small block of the engine to be replaced or something to the effect. By this time I had already traded in the vehicle. This sounds an awful lot like the issue that Subaru had. From my trusted mechanic “a new car should never consume/use/burn oil…”

    Reply

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