For the 1985 Chevrolet Impala 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 SAE 30 is preferred for temperatures above 0°C. AMSOIL recommends using Signature Series 10W-30 100% Synthetic Max-Duty Diesel Oil (DTTQT-EA) paired with an AMSOIL Oil Filter (EAO64-EA).
What oil does a 1985 Chevrolet Impala 5.7L Diesel take?
The engine requires an oil with a CF grade specification. Depending on your operating environment, the recommended viscosity varies: use 10W-30 for temperatures below 16°C, 15W-40 for temperatures between -18°C and 16°C, or SAE 30 for temperatures above 0°C (where SAE 30 is preferred).
AMSOIL Product Recommendations
To simplify your maintenance, AMSOIL offers high-performance synthetic fluids and filters specifically selected for the 5.7L Diesel engine requirements.
Engine Oil Options
| Product Name | Viscosity | Code |
|---|---|---|
| AMSOIL Signature Series Max-Duty Diesel Oil | 10W-30 | DTTQT-EA |
| AMSOIL 10W-30 Heavy-Duty Diesel Oil | 10W-30 | ADNQT-EA |
| AMSOIL Signature Series Max-Duty Diesel Oil | 5W-30 | DHDQT-EA |
Oil Filter Recommendation
| Product Name | Code |
|---|---|
| AMSOIL Oil Filter | EAO64-EA |
Coolant & Transmission Fluids
| Component | Product Name | Code |
|---|---|---|
| Coolant | Passenger Car & Light Truck Antifreeze | ANTPC1G-EA |
| Coolant | Propylene Glycol Antifreeze | ANT1G-EA |
| ATF | Signature Series Fuel-Efficient ATF | ATLPK-EA |
| ATF | OE Fuel-Efficient ATF | OTLQT-EA |
Engine Oil Specifications
| Specification | Details |
|---|---|
| Oil Grade | CF |
| Preferred Viscosity (Above 0°C) | SAE 30 |
Engine Oil Capacity & Torque
| Measurement | Value |
|---|---|
| Oil Capacity (with filter) | 7 quarts |
| Oil Drain Plug Torque | 30 ft/lbs |
Note: Always check the oil level after refilling.
Automatic Transmission Fluid Specifications
For the automatic transmission, the manufacturer’s technical service bulletin indicates that the specification has been updated from Dexron II or III to Dexron VI. Ensure you select the correct fluid for your specific transmission model (THM200-4R, THM200C, or THM700-R4).
Transmission Capacity Guide
| Transmission Model | Total Fill | Initial Fill |
|---|---|---|
| THM200-4R (4 Speed) | 11 quarts | 5 quarts |
| THM200C (3 Speed) | 9.4 quarts | 3.5 quarts |
| THM700-R4 (4 Speed) | 10.9 quarts | 5 quarts |
Diesel maintenance notes for this vehicle
Maintaining a vintage diesel engine requires attention to several key areas:
- Fuel System Integrity: Given the age of these vehicles, owners should monitor fuel injection components and the condition of fuel hoses.
- Cooling Efficiency: Ensure the cooling system is free of leaks and uses compatible antifreeze to protect metals and gaskets.
- Oil Level Monitoring: After every oil change, verify the level using the dipstick to ensure the 7-quart capacity was met correctly.
Common diesel oil-related concerns and how AMSOIL products may help
| Concern | Why it matters | AMSOIL Product | How it may help | Limitation |
|---|---|---|---|---|
| Engine Wear | Diesel engines face high pressure and friction. | DTTQT-EA | Delivers up to 6X more wear protection. | Requires regular oil changes. |
| Extreme Temperatures | Viscosity changes can affect lubrication. | ADNQT-EA | Excels in extreme temperatures. | Not a substitute for proper viscosity selection. |
| Contaminants | Small particles cause abrasive wear. | EAO64-EA | 99% efficiency at 20 microns. | Filter must be replaced per service interval. |
Common maintenance concerns for this vehicle
Based on historical context and research, owners of mid-1980s Chevrolet diesel vehicles should consider the following:
- Fuel System: Check for degraded rubber vacuum lines or fuel hoses that may have aged over time.
- Glow Plugs: Ensure glow plug functionality is maintained for reliable cold starts.
- Cooling System: Inspect all cooling system metals, gaskets, and hoses for signs of degradation.
Recall, TSB, and manufacturer communication notes
Official NHTSA recall research for the 1985 Chevrolet Impala identified one recall record:
- Campaign 06E043000: Related to certain replacement fuel filters (Fram Brand P/N G3727). The connector may not have met specifications, potentially leading to an inadequate seal and fuel leaks.
Disclaimer: Always verify open recalls by using your specific Vehicle Identification Number (VIN) through official manufacturer or NHTSA channels.
About this vehicle
The 1985 Chevrolet Impala represents the final year of the original production run for this iconic full-size nameplate, which spanned from 1958 to 1985. Historically, the Impala served as Chevrolet’s flagship passenger car and was a staple of American automotive culture throughout much of the 20th century.
During its later years, specifically in the late 1970s and early 1980s, the model transitioned from high-trim luxury options to foundational full-size sedan models. This specific variant features a 5.7L 8-cylinder diesel engine (Engine Code N). While this powertrain is part of the era’s GM diesel landscape, owners should verify if their specific mechanical architecture belongs to a particular GM diesel family used in B-body vehicles before performing deep engine work.
Maintenance for these vehicles often focuses on fuel system integrity and cooling efficiency. Because these vehicles are from a long production era, finding parts may involve looking into shared components with other GM full-size models of the same period. Owners should consult dedicated service manuals to confirm exact mechanical specifications for their specific engine configuration.
Common questions about this vehicle’s diesel oil and maintenance
How much oil does my 1985 Impala 5.7L Diesel take?
It takes 7 quarts of oil when performing a service that includes a filter change.
What is the correct oil viscosity for cold weather?
For temperatures below 16°C, 10W-30 is recommended. For temperatures between -18°C and 16°C, 15W-40 is suggested.
Can I use Dexron III in my transmission?
The manufacturer’s technical service bulletin indicates that the specification has been updated from Dexron II or III to Dexron VI for this application.
What should I check regarding my fuel system?
Owners should inspect fuel hoses and injection components, as rubber lines can degrade over time in older diesel vehicles.
Does AMSOIL offer a filter for this engine?
Yes, the AMSOIL Oil Filter (EAO64-EA) is recommended for this vehicle.
How do I verify if my vehicle has an active recall?
You should contact a local dealer or use the NHTSA website to check your specific VIN for any open recalls or manufacturer communications.
Verification Disclaimer: While we strive for accuracy, please consult your owner’s manual or a certified mechanic to confirm all specifications and service requirements for your specific vehicle.