What oil does a 2021 GMC Sierra 1500 3.0L Diesel take?
The 2021 GMC Sierra 1500 with the 3.0L 6-cylinder LM2 T Diesel Turbo engine requires a 0W-20 viscosity oil. For a standard oil change including the filter, the required capacity is 7.0 quarts. AMSOIL recommends using AMSOIL 0W-20 100% Synthetic Diesel Oil (DP020QT-EA) paired with a WIX Oil Filter (WL10351-EA).
AMSOIL product recommendations
The following AMSOIL and WIX products are recommended for your 2021 GMC Sierra 1500 3.0L LM2 T Diesel Turbo engine and related systems based on available lookup data.
Engine Oil & Filter
| Product Name | Viscosity/Grade | Part Code |
|---|---|---|
| AMSOIL 0W-20 100% Synthetic Diesel Oil | 0W-20 (SEOA5) | DP020QT-EA |
| Filter Type | Part Number |
|---|---|
| WIX Oil Filter | WL10351-EA |
Transmission & Transfer Case
| Application | Product Name | Part Code |
|---|---|---|
| Automatic Transmission | AMSOIL Signature Series ULV 100% Synthetic ATF | ULVPK-EA |
| Automatic Transmission | AMSOIL Signature Series Fuel-Efficient 100% Synthetic ATF | ATLPK-EA |
| Automatic Transmission | AMSOIL OE Fuel-Efficient 100% Synthetic ATF | OTLQT-EA |
| Transfer Case | AMSOIL Signature Series Fuel-Efficient 100% Synthetic ATF | ATLPK-EA |
Coolant & Brake Fluid
| Application | Product Name | Part Code |
|---|---|---|
| Engine Coolant | AMSOIL Passenger Car & Light Truck Antifreeze & Coolant | ANTPC1G-EA |
| Engine Coolant | AMSOIL Propylene Glycol Antifreeze and Engine Coolant | |
| Brake Fluid | AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid | Not confirmed from source data |
Differential/Gear Lube
| Product Name | Part Code |
|---|---|
| AMSOIL SEVERE GEAR® 75W-85 100% Synthetic Gear Lube | SVLPK-EA |
Engine Oil Specifications & Details
Proper lubrication is vital for the 3.0L LM2 Turbo Diesel engine to ensure longevity and performance under heavy loads.
Oil Viscosity and Capacity
| Specification | Value |
|---|---|
| Viscosity | 0W-20 (All TEMPS) |
| Oil Grade (AMSOIL lookup) | SEOA5 |
| Capacity (with filter) | 7.0 Quarts |
Service Specifications
- Oil Drain Plug Torque: 18 ft/lbs (Replace drain plug seal).
- Note on Diesel Standards: Vehicles equipped with diesel engines that originally used GM Dexos2 may use a GM Dexos D licensed engine oil of the appropriate viscosity grade.
Transmission & Transfer Case Details
The 10-speed automatic transmission requires specific fluids to maintain smooth shifting and durability.
Automatic Transmission (10L80)
| Condition | Capacity |
|---|---|
| Total Fill (without cooler) | 12.6 quarts |
| Total Fill (with cooler) | 12 quarts |
| Initial Fill | 8.1 quarts |
Note: The AMSOIL lookup note references the WSS-M2C949-A specification for this application, noting it was developed by Ford and GM.
Transfer Case (MP3015, 25…AF6)
| Specification | Value |
|---|---|
| Capacity | 3.2 pints |
| Drain Plug Torque | 15 ft/lbs |
| Fill Plug Torque | 15 ft/lbs |
Coolant Specifications
Maintaining the cooling system is essential for preventing engine overheating in diesel applications.
| Component | Capacity |
|---|---|
| Engine Coolant | 20.5 quarts |
Diesel maintenance notes for this vehicle
Based on the technical data, owners of the 3.0L LM2 diesel should consider the following:
- Oil Level Verification: Always check the oil level after refilling during an oil change.
- Seal Replacement: It is recommended to replace the drain plug seal when performing service.
- Coolant Management: For concentrated products like ANT1G-EA, ensure proper mixing with distilled or high-quality water.
- Diesel Specifics: Maintenance should focus on fuel system cleanliness and turbocharger protection due to the high-pressure common rail and turbo architecture.
Common diesel oil-related concerns and how AMSOIL products may help
| Concern | Why it matters | AMSOIL product from this lookup | How it may help | Important limitation |
|---|---|---|---|---|
| Turbocharger Wear | High RPMs and heat can degrade lubrication. | DP020QT-EA | Designed to retain viscosity for added protection. | Requires regular oil change intervals. |
| Heavy Towing Heat | Increased transmission temperatures during towing. | ULVPK-EA | Withstands the rigors of heavy towing and elevated temperatures. | Diagnosis required if mechanical failure occurs. |
| Engine Overheating | Diesel engines generate significant thermal loads. | ANTPC1G-EA | Protects all cooling system metals, gaskets, and hoses. | Does not repair existing leaks or valve failures. |
Common maintenance concerns for this vehicle
Based on NHTSA consumer reports, owners have noted several areas of concern. Please note that these are owner-reported complaints and not verified manufacturer defects:
- Engine Performance: Reports of engine shaking or misfires at idle.
- Cooling System: Complaints regarding coolant control valve failures and exhaust fan operation.
- Transmission: Some reports mention rough downshifting or slipping during operation.
Recall, TSB, and manufacturer communication notes
Official NHTSA research indicates the following recall information for certain 2021 GMC Sierra 1500 models:
- Seat Belt Brackets: A recall (Campaign 20V792000) was issued because seat belt brackets may not be secured to the seat frame in the front-row center position.
- Seat Belt Bolts: A recall (Campaign 20V811000) addressed incorrect bolts used at fastening locations for seat belts.
- Tires: A recall (Campaign 20V684000) was noted regarding Continental tires that may have been overcured.
Important: Always verify your specific vehicle’s open recalls by using your VIN through the GMC owner portal or NHTSA website.
About this vehicle
The 2021 GMC Sierra 1500 is a full-size pickup truck manufactured by General Motors. This model shares significant mechanical commonality with its sibling, the Chevrolet Silverado. Within the GM truck lineup, the Sierra often serves as a primary light-duty offering, frequently positioned alongside premium trim levels such as the Denali, which represents GMC’s high-end luxury tier.
This specific vehicle is equipped with the 3.0L 6-cylinder LM2 Turbo Diesel engine, part of the GM Duramax family. The Duramax nameplate is synonymous with General Motors’ diesel technology. Because this is a diesel-powered variant of a full-size pickup, typical use cases include heavy towing, long-distance hauling, and applications requiring high fuel efficiency compared to traditional gasoline engines.
Owners of the LM2 diesel engine often focus their research on specialized maintenance requirements unique to compression-ignition engines. These include maintaining fuel system cleanliness, monitoring glow plug operation, and managing Diesel Exhaust Fluid (DEF). Because diesel engines operate under different thermal and pressure profiles than gasoline counterparts, adhering to precise lubrication and filtration standards is paramount for engine longevity.
Common questions about this vehicle’s diesel oil and maintenance
How much oil does my 3.0L Duramax take?
The 3.0L LM2 Diesel engine requires 7.0 quarts of oil when performing a change that includes the filter.
What is the correct oil viscosity for the 2021 GMC Sierra 1500 diesel?
The recommended viscosity for this application is 0W-20.
Can I use standard ATF in my 10-speed transmission?
The AMSOIL lookup note references the WSS-M2C949-A specification for this application. It recommends products like ULVPK-EA or OTLQT-EA.
What should I do if my engine is shaking at idle?
While some owners have reported misfires or vibrations, this may be related to various components. You should consult a certified technician for diagnosis.
How often should I change my diesel engine oil?
Maintenance intervals should follow the specific requirements found in your owner’s manual, especially if using the vehicle for heavy towing or severe service.
How do I check for recalls on my GMC Sierra?
You should verify all open recalls by entering your VIN on the official GMC website or the NHTSA website.
Disclaimer: Information provided is based on available source data. Always consult your owner’s manual and a certified professional before performing vehicle maintenance.