For the 1980 Cadillac DeVille with the 5.7L 8-cylinder Engine (Code N) Diesel, the oil capacity is 7 quarts (including filter replacement). Recommended viscosities include 10W-30 for temperatures below 16°C, 15W-40 for -18°C to 16°C, and 30 weight for continuous driving above 0°C. AMSOIL recommends using Signature Series 10W-30 Max-Duty Diesel Oil and the EAO64-EA Oil Filter.
What oil does a 1980 Cadillac DeVille 5.7L Diesel take?
The engine requires an oil with a CF grade specification. Depending on your operating environment, you should select the appropriate viscosity to ensure proper lubrication and protection.
AMSOIL product recommendations
The following AMSOIL products are specifically listed for your 1980 Cadillac DeVille 5.7L Diesel to support engine longevity and performance.
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 Recommendation
| 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 | Status |
|---|---|
| Oil Grade | CF |
Engine Oil Viscosity Guide
| Temperature Range | Recommended Viscosity |
|---|---|
| Below 16°C | 10W-30 |
| -18°C to 16°C | 15W-40 |
| Above 0°C (Continuous Driving) | 30 |
How much oil does it take with a filter change?
For the 5.7L 8-cylinder diesel engine, the total capacity is 7 quarts when performing an oil change that includes a new filter. Always check the oil level after refilling to ensure accuracy.
Oil Drain Plug Torque
| Component | Torque Value |
|---|---|
| Oil Drain Plug | 30 ft/lbs |
Automatic Transmission Fluid Specifications
The 1980 Cadillac DeVille uses various transmission models. Note that manufacturer technical service bulletins have updated the specification from Dexron II or III to Dexron VI for these applications.
Transmission Capacity & Models
| Transmission Model | Total Fill Capacity | Initial Fill |
|---|---|---|
| THM350 | 10 quarts | 3.2 quarts |
| THM250C | 10.8 quarts | 4.2 quarts |
| THM400 | 11 quarts | 3.2 quarts |
| THM200 | 12 quarts | 3.2 quarts |
Coolant Specifications
The cooling system requires a capacity of 23.8 quarts. Proper coolant maintenance is vital for protecting all cooling system metals, gaskets, and hoses.
Coolant Options
- AMSOIL Passenger Car & Light Truck Antifreeze: A 50/50 pre-mix ethylene glycol formulation.
- AMSOIL Propylene Glycol Antifreeze: A concentrated formula that requires mixing with distilled or high-quality water.
Diesel maintenance notes for this vehicle
Maintaining a vintage diesel engine like the 5.7L Code N requires attention to specific systems:
- Oil Level: Always verify the oil level after refilling, as the 7-quart capacity includes the filter volume.
- Air Filtration: No AMSOIL recommendations are currently available for the air filter or oil vapor filter for this specific model.
- Cooling System: Ensure the use of a compatible coolant to prevent corrosion; AMSOIL options are phosphate-, nitrate-, nitrite-, silicate-, borate-, and amine-free.
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. | Signature Series 10W-30 | Delivers up to 6X more wear protection. | Requires proper maintenance intervals. |
| Contaminants | Small particles can cause abrasive wear. | EAO64-EA Filter | 99% efficiency at 20 microns; greater capacity for small contaminants. | Filter must be replaced regularly. |
| Extreme Temperatures | Viscosity changes can affect lubrication. | Signature Series 5W-30 | Excels in extreme temperatures and maintains proper viscosity. | Select viscosity based on ambient temperature. |
Common maintenance concerns for this vehicle
Owners of vintage GM diesel platforms should consider the following:
- Fuel System Integrity: Diesel engines of this era require careful monitoring of fuel system health.
- Glow Plug Functionality: Essential for reliable starting in cooler temperatures.
- Cooling Efficiency: Maintaining proper coolant levels and quality is critical to prevent head gasket issues.
About this vehicle
The 1980 Cadillac DeVille represents a specific era in Cadillac’s history, characterized by the brand’s transition through various luxury sedan generations. While the DeVille nameplate has been used across eight different generations, the 5.7L Diesel variant was part of a broader GM era where diesel technology was explored within luxury platforms.
This specific 5.7L engine (Code N) is a notable example of Cadillac’s attempt to combine high-comfort cruising and long-distance travel with the fuel efficiency characteristics of diesel power. Because these engines differ significantly from the gasoline V8 engines that defined much of Cadillac’s legacy, owners should treat engine-specific details with caution and prioritize specialized maintenance.
From a maintenance perspective, diesel engines of this vintage require specialized attention regarding fuel system integrity, glow plug functionality, and cooling system efficiency. Owners should cross-reference all technical details with official GM service literature to ensure accuracy, as these requirements differ from standard gasoline engine service protocols.
Recall, TSB, and manufacturer communication notes
Official NHTSA recall research for the 1980 Cadillac DeVille returned no records. However, owners should always verify open recalls by VIN, as applicability depends on production date, trim, and specific equipment. Regarding the automatic transmission, a Technical Service Bulletin from the manufacturer indicates that the specification has been updated from Dexron II or III to Dexron VI.
Common questions about this vehicle’s diesel oil and maintenance
What is the oil capacity for my 1980 Cadillac DeVille Diesel?
The capacity is 7 quarts when including a filter change. Always check the level after refilling.
Which AMSOIL oil is best for extreme protection?
The Signature Series 10W-30 is designed to deliver up to 6X more wear protection based on Detroit Diesel DD13 Scuffing Test results.
What transmission fluid should I use?
The AMSOIL lookup notes that the specification has been updated to Dexron VI. The lookup lists Signature Series Fuel-Efficient ATF for this application.
How often can I change my oil?
AMSOIL synthetic products are designed to allow you to confidently extend drain intervals, though you should follow your specific engine’s service requirements.
Does the 1980 DeVille have any known recalls?
NHTSA research returned no complaint or recall records for this model year, but you should verify your specific VIN with a dealer.
What viscosity should I use in winter?
For temperatures below 16°C, 10W-30 is recommended. For colder ranges between -18°C and 16°C, 15W-40 is suggested.
Disclaimer: Not all information provided is a substitute for professional mechanical advice. Always verify specifications in your owner’s manual or with a certified technician.