For the 1980 GMC C1500 2WD Pickup with the 5.7L 8-cylinder Diesel engine (Engine Code Z), the oil capacity is 7 quarts when changing with a filter. The recommended oil viscosity is 10W-30 for temperatures below 20°C and 30 for temperatures above 0°C. AMSOIL recommends using Signature Series 10W-30 Max-Duty Diesel Oil (DTTQT-EA) paired with an AMSOIL Oil Filter (EAO64-EA).
What oil does a 1980 GMC C1500 Diesel take?
The engine requires an oil with a CF grade. Depending on your operating environment, the recommended viscosity is 10W-30 for temperatures below 20°C and 30 for temperatures above 0°C.
AMSOIL product recommendations
The following AMSOIL products are recommended for your 1980 GMC C1500 diesel maintenance based on the provided vehicle lookup data.
Engine Oil Options
| Product Name | Code |
|---|---|
| AMSOIL Signature Series 10W-30 100% Synthetic Max-Duty Diesel Oil | DTTQT-EA |
| AMSOIL 10W-30 Heavy-Duty 100% Synthetic Diesel Oil | ADNQT-EA |
| AMSOIL Signature Series 5W-30 100% Synthetic Max-Duty Diesel Oil | DHDQT-EA |
Oil Filter
| Product Name | Code |
|---|---|
| AMSOIL Oil Filter | EAO64-EA |
Coolant & Antifreeze
| Product Name | Code |
|---|---|
| AMSOIL Passenger Car & Light Truck Antifreeze & Coolant | ANTPC1G-EA |
| AMSOIL Propylene Glycol Antifreeze and Engine Coolant | ANT1G-EA |
Automatic Transmission Fluid
| Product Name | Code |
|---|---|
| AMSOIL Signature Series Fuel-Efficient 100% Synthetic ATF | ATLPK-EA |
| AMSOIL OE Fuel-Efficient 100% Synthetic ATF | OTLQT-EA |
Engine Oil Specifications
| Specification | Detail |
|---|---|
| Oil Grade | CF |
| Viscosity (Below 20°C) | 10W-30 |
| Viscosity (Above 0°C) | 30 |
Engine Oil Capacity
| Condition | Capacity |
|---|---|
| With Filter Change | 7 quarts |
Note: After refill, always check the oil level.
How much transmission fluid does it take?
Capacity varies depending on your specific automatic transmission model (THM350 or THM400). The AMSOIL lookup notes that for these applications, specifications have been updated from Dexron II or III to Dexron VI per a manufacturer Technical Service Bulletin.
THM350 Transmission Capacity
| Type | Capacity |
|---|---|
| Total Fill (3-speed) | 10 quarts |
| Initial Fill | 3.5 quarts |
THM400 Transmission Capacity
| Type | Capacity |
|---|---|
| Total Fill (3-speed) | 11 quarts |
| Initial Fill | 4.3 quarts |
Diesel maintenance notes for this vehicle
When performing maintenance on the 5.7L Diesel (Engine Code Z), ensure you are using the correct viscosity to manage engine wear and temperature. For cooling system maintenance, the capacity is 24.3 quarts. If using concentrated antifreeze like ANT1G-EA, it requires mixing with distilled or high-quality water.
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 |
|---|---|---|---|---|
| Engine Wear | Diesel engines face high pressure and friction. | DTTQT-EA | Delivers up to 6X more wear protection. | Requires regular oil changes. |
| Contaminants | Small particles can cause abrasive wear. | EAO64-EA | 99% efficiency at 20 microns. | Filter must be replaced per interval. |
| Extreme Temperatures | Viscosity changes can affect lubrication. | DTTQT-EA | Excels in extreme temperatures. | Not a substitute for proper viscosity selection. |
Common maintenance concerns for this vehicle
Owners of this vintage diesel platform should regularly monitor fluid levels and quality. Key areas include checking for oil consumption, ensuring the cooling system is free of corrosion, and verifying transmission fluid condition to prevent shudder or slipping.
Recall, TSB, and manufacturer communication notes
Official NHTSA recall research for the 1980 GMC C1500 2WD Pickup returned no recall records. Additionally, no consumer complaints were found in the NHTSA database for this specific year/make/model combination. However, owners should always verify open recalls by VIN as applicability can depend on production date and equipment.
About this vehicle
The 1980 GMC C1500 2WD Pickup equipped with the 5.7L V8 diesel engine (Engine Code Z) is a unique piece of automotive history. It is important to note that while modern users may associate the term “Duramax” with GM diesel engines, the Duramax family did not enter production until approximately 2001. This 1980 model utilizes an engine from the Oldsmobile Diesel series, which was based on the Oldsmobile 350 gasoline architecture and produced by General Motors between 1978 and 1985.
This specific 5.7L (350 cu in) V8 diesel configuration is historically noted for having complex maintenance requirements. It is often contrasted with the later, more reliable 6.2L Detroit Diesel V8 engines that became common in GMC trucks starting around 1982. Because this engine architecture differs significantly from modern GM diesel families, owners are encouraged to consult period-correct service manuals to ensure they are using the correct viscosity and specifications for this specific Oldsmobile-based platform.
Common questions about this vehicle’s diesel oil and maintenance
How much oil does my 1980 GMC C1500 5.7L Diesel take?
It takes 7 quarts of oil with a filter change. Always check the level after refilling.
What is the correct oil viscosity for this engine?
The AMSOIL lookup recommends 10W-30 for temperatures below 20°C and 30 for temperatures above 0°C.
Can I use modern Dexron fluids in my transmission?
The vehicle’s THM350/THM400 transmissions have been updated from Dexron II or III to Dexron VI per manufacturer Technical Service Bulletins. AMSOIL offers ATLPK-EA and OTLQT-EA for these applications.
What is the coolant capacity?
The cooling system capacity is 24.3 quarts.
Does this vehicle have any active recalls?
NHTSA research returned no recall records for this model, but you should always verify your specific VIN with a dealer.
What kind of oil filter should I use?
An AMSOIL Oil Filter such as EAO64-EA is recommended for high filtering efficiency.
Disclaimer: This information is derived from provided source data. Always consult your vehicle’s owner manual or a professional mechanic to confirm specifications before performing maintenance.