LZ0 Turbocharger Replacements: What GM’s New Bulletin Says About Oil—and What Owners Should Do

Greg Nelson
Oct 22
3 min read

Bulletin: GM Service Bulletin # 25-NA-202 (Oct 21, 2025) — “LZ0 Turbocharger Replacement.”Vehicles: 2023–2026 Silverado/Sierra 1500 (LZ0), 2025 Tahoe/Suburban/Yukon with LZ0.

The Issue?

GM notes a portion of LZ0 turbo failures are associated with incorrect engine oil and/or low oil level. Translation: your turbo’s life hinges on using the exact diesel spec and keeping the sump properly filled. (Bulletin # 25-NA-202 summary.)

What “wrong oil” means on the LZ0

The 3.0L Duramax calls for SAE 0W-20 engine oil that meets GM’s diesel spec (dexosD)—not dexos1 (gasoline) and not “meets/exceeds” claims without a current license. GM’s Diesel Engine Supplement explicitly specifies 0W-20 and to choose oil that meets the correct specification. (GM-Trucks.com)

You (or your quick-lube) can verify products on GM’s official dexosD licensed brands list. Look for the dexos® icon and license number on the bottle. (GMD Exos)

Editor’s pick (full kit): Your trusted LZ0 oil-change kit: Amazon kit (dexosD 0W-20 + filter). Best filter choice: The filter you consider “the best”: Amazon filter.Disclosure: These are affiliate links; purchasing through them may support DuramaxNews at no extra cost to you.

Why this matters: Diesel oils differ in soot handling/dispersion, turbo deposit control, and low-SAPS chemistry for DPF longevity. Using a gasoline oil (dexos1) or a non-licensed substitute raises coking/deposit risk in a liquid-cooled, ball-bearing VGT like the LZ0’s Garrett unit.

Is 0W-20 “too thin,” or is misfill/maintenance the issue?

Licensed dexosD 0W-20 is designed for turbocharged light-duty diesels. When oil “breaks down,” the common culprits are extended intervals, contamination (fuel dilution), high heat, or running low, not the grade alone. GM’s bulletin calling out low oil directly underscores that level control is just as critical as spec compliance. (GM-Trucks.com)

Symptoms we see when an LZ0 turbo is failing

Large oil leak around the turbo area
Smoke from the turbo (burn-off or oil entering the exhaust)
Lack of power
Stored underboost DTCs (P0299) — generic “turbo underboost” when measured boost is below limits.

What dealers are instructed to do under # 25-NA-202

If turbo replacement is required, the bulletin directs technicians to:

Replace the turbocharger (follow SI: “Compressor Air Intake Turbocharger Replacement”).
Replace the turbocharger oil feed pipe (fresh, unrestricted supply to protect the new unit).

Replacing the feed line is standard practice on turbo jobs where restriction/coking is possible—it reduces immediate repeat-failure risk. (Per GM service communications and SI conventions.)

LZ0 turbo hardware context

The LZ0 uses a Garrett variable-geometry, water-cooled, ball-bearing turbo—highly responsive but unforgiving of oil spec/level errors.

Owner checklist (5 minutes)

Use licensed dexosD 0W-20 only; verify on GM’s dexosD list. (GMD Exos)
Check oil level correctly (level ground, hot soak) and top off as needed between changes.
Shorten intervals if you tow, idle a lot, see high heat, or your used-oil analysis shows fuel dilution/oxidation.
Warm-down after heavy load (30–60 s easy idle) to control turbo center-housing temperatures.
If a turbo is replaced, confirm the oil feed line was replaced and the drain path is clear.

Bottom line (DuramaxNews take)

The language in # 25-NA-202 points to misfilled oil (gasoline spec) and/or low oil as meaningful contributors—not a systemic failure of properly-licensed dexosD 0W-20. The LZ0’s Garrett VGT is stout, but oil spec and oil level are non-negotiable. Control both, and you drastically reduce the odds of ending up in the replacement lane.