Keeping your 1987 Chevrolet Blazer running smoothly requires attention to detail, especially when it comes to the fluids that keep the engine and drivetrain lubricated. This classic SUV, powered by the robust 5.0L V8 engine (Engine Code H), is known for its durability and off-road capability, but like any vehicle from the 1980s, it demands high-quality maintenance to prevent premature wear. The correct viscosity and formulation are critical for managing the internal temperatures and friction levels found in this older powertrain. By choosing the right AMSOIL synthetic lubricants, you can significantly reduce the frequency of maintenance tasks while extending the life of critical components.
Recommended AMSOIL Products
- AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil – Provides the highest level of protection with up to 25,000 miles of guaranteed service. This premium oil offers superior resistance to heat and wear, ensuring the engine runs cleaner and smoother for the long haul.
- AMSOIL Extended-Life 5W-30 100% Synthetic Motor Oil – An excellent choice for extended service intervals, offering 20,000 miles of protection. It features enhanced cleaning power to help maintain engine efficiency and is particularly effective at preventing Low-Speed Pre-Ignition (LSPI).
- AMSOIL OE 5W-30 100% Synthetic Motor Oil – Designed to outperform conventional OEM oils and meet the requirements of GM dexos1 Gen 2 specifications. This formulation fights sludge and deposits, making it an ideal replacement for those seeking a balance of performance and value.
- AMSOIL 5W-30 100% Synthetic High-Mileage Motor Oil – Specifically formulated for engines with over 75,000 miles, this oil contains a boosted detergent package and enhanced anti-wear additives to reduce sludge and improve seal conditioning.
- AMSOIL Oil Filter – Engineered to provide filtering efficiency of 99 percent at 20 microns. This heavy-duty filter offers greater capacity for small, wear-causing contaminants than many competing brands, ensuring the oil stays clean.
- WIX Oil Filter – A premium aftermarket option that offers improvements over original equipment manufacturer-branded filters, providing reliable protection for your 1987 Blazer’s V8 engine.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A unique poly-organic acid (OAT) formulation that protects all cooling system metals, gaskets, and hoses. It offers protection for up to 150,000 miles or 5 years and is compatible with other antifreeze colors.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated option requiring mixing, this coolant delivers exceptional protection against metallic corrosion and erosion, surpassing standard industry requirements for long-term cooling system health.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Capable of withstanding the rigors of heavy towing, elevated temperatures, and challenging terrain. It remains fluid in sub-zero temperatures and provides reserve protection during heavy use.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Protects against wear and is a cost-effective synthetic option for automatic transmissions requiring Dexron VI specification fluids.
- AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube – Offers advanced protection against wear and rust for both manual transmissions and differentials. It contains friction modifiers for limited-slip applications and helps reduce operating temperatures.
- AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube – A high-performance alternative that controls thermal runaway and extends the life of seals and gears in your Blazer’s transfer case and rear differential.
- AMSOIL SEVERE GEAR® 75W-110 100% Synthetic Gear Lube – Provides heavy-duty protection for demanding applications, ensuring long oil and equipment life even under extreme load conditions.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Delivers excellent ABS and traction-control responsiveness with a stable viscosity over a wide temperature range, ensuring consistent braking performance in any weather.
Engine Oil Selection for the 5.0L V8
The heart of your 1987 Chevrolet Blazer is the 5.0-liter (305 cubic inch) V8 engine. For this specific powerplant, AMSOIL recommends SAE 5W-30 as the preferred viscosity for all temperatures. The capacity for a standard oil change, including the filter, is 5.0 quarts. While conventional oils might have been the standard when the vehicle was new, synthetic motor oil provides superior performance for this older engine design, particularly in terms of thermal stability and deposit control.
AMSOIL Signature Series 5W-30 is the top recommendation for maximum protection. It contains a unique blend of additives that can provide up to 25,000 miles of engine protection between oil changes under normal driving conditions. This is a significant advantage for owners of vintage vehicles, as it reduces the time and effort spent on maintenance. The oil is tested to provide 75% more engine protection against horsepower loss and wear compared to industry standards. For owners of high-mileage Blazers that have accumulated over 75,000 miles, the AMSOIL High-Mileage 5W-30 is an excellent choice. It features a unique chemistry designed to condition seals, reduce sludge, and boost detergency to clean up internal deposits, helping the engine run smoother.
Transmission and Transfer Case Lubrication
The 1987 Blazer typically came equipped with either a THM400 (3-speed) or a THM700-R4 (4-speed) automatic transmission. Both of these transmissions have been updated by the manufacturer to use Dexron VI fluid specifications, which is a significant upgrade over the older Dexron II or III fluids once recommended. Using a fluid that meets the current Dexron VI specification is essential for proper shifting quality and transmission longevity.
For the automatic transmission, AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is the premier choice. It is formulated to withstand the heat and stress generated by the Blazer’s four-wheel-drive system, especially during off-road driving or towing. The fluid is designed to remain fluid in sub-zero temperatures and provide reserve protection during heavy use. The OE Fuel-Efficient version is a solid alternative that also meets Dexron VI specifications, offering reliable protection against wear and sludge.
The transfer case, a critical component for the 4WD system, requires specific lubrication. Depending on whether your vehicle has an NP205 or NP208 transfer case, the fill capacity varies between 5.1 pints and 10.1 pints. For both manual transmissions (such as the SM465) and transfer cases, AMSOIL SEVERE GEAR 80W-90 or 75W-90 synthetic gear lube is recommended. These lubes contain friction modifiers for limited-slip differentials and are designed to control thermal runaway, protecting the gears and bearings from wear even when the vehicle is operating under extreme conditions.
Cooling and Brake Systems
Maintaining the cooling system is vital for preventing overheating, which can be a common issue in older engines with accumulated carbon deposits. The 1987 Blazer requires a substantial amount of coolant, with a total capacity of 18 quarts. AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a phosphate-, nitrate-, and silicate-free formulation that is compatible with all other antifreeze colors. It is designed to protect the cooling system’s metals, gaskets, and hoses for up to 150,000 miles. For those who prefer a concentrated coolant that allows for precise mixing, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant offers extensive protection against corrosion and erosion.
Brake safety cannot be overlooked. The 1987 Blazer uses DOT 3 hydraulic brake fluid. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid offers superior performance over conventional fluids. It maintains a stable viscosity over a wide temperature range, ensuring consistent pedal feel and responsive braking. This synthetic fluid also helps prevent boiling under heavy braking conditions, which is crucial for a vehicle that may be used for towing or driving on steep terrain.
Maintenance for the WIX Filters
While AMSOIL filters are highly regarded, WIX filters are also available and offer premium media that improves upon OEM-branded filters. The WIX Oil Filter (51061) is a compatible option for the 5.0L engine. Additionally, the WIX Air Filter (42098) helps ensure clean air intake, which is essential for fuel efficiency and engine performance. For crankcase ventilation, the WIX Crankcase Filter (42995) is an effective upgrade to manage oil vapor. In the transmission, the WIX Transmission Filter (58881) helps keep the fluid clean, extending the life of the transmission system.
Seasonal Storage and Fuel Treatment
If you plan to store the 1987 Blazer for an extended period, such as during winter months, AMSOIL Gasoline Stabilizer can help keep the fuel fresh for up to 12 months. This additive fights ethanol corrosion and prevents varnish and gum buildup in the carburetor or fuel injection system. Additionally, AMSOIL Engine Fogging Oil can be used to protect internal engine components from rust and corrosion during storage.
For improved performance and fuel economy, AMSOIL P.i. Performance Improver Gasoline Additive is highly recommended. This concentrate restores up to 14% of horsepower and helps clean GDI fuel injectors, improving flow rates and fuel economy. It also reduces the need for higher-octane fuel and helps prevent carbon buildup and pre-ignition knock.
Vehicle Background
The 1987 Chevrolet Blazer represents a significant era in American automotive history, serving as the quintessential mid-size SUV of the late 1980s. Based on the Chevy pickup truck platform, this model was designed with a strong emphasis on off-road capability and rugged utility. Powered by a choice of engines, the 5.0L (305 cubic inch) V8 was one of the most popular options, offering a balance of adequate power and fuel efficiency that appealed to a wide range of drivers.
This vehicle was renowned for its durability and simplicity. The Blazer’s design featured a body-on-frame construction, which contributed to its strength and ability to handle rough terrain. The 5.0L V8 engine, often identified by the “H” engine code, was a workhorse known for its reliability and ease of maintenance. It was a staple for farmers, hunters, and families who needed a vehicle that could handle a variety of driving conditions, from paved roads to unpaved trails. The Blazer’s two-door configuration offered a compact and maneuverable profile, making it a favorite for recreational use.
Despite its robust construction, owners of the 1987 Blazer may encounter several common issues that can be mitigated with the use of high-quality synthetic lubricants. One prevalent problem is oil consumption, which can occur as engines age and seals harden. The use of AMSOIL High-Mileage motor oil can help condition these seals, reducing oil consumption and preventing leaks. Another common issue is sludge buildup in the crankcase, which can restrict oil flow and cause premature wear on camshafts and lifters. AMSOIL motor oils are formulated with enhanced cleaning agents that effectively break down sludge and prevent new deposits from forming, keeping the engine internals clean and functioning smoothly.
Thermal breakdown is also a concern for this older engine, particularly during extended periods of towing or idling in hot weather. The synthetic base stocks in AMSOIL oils provide superior resistance to heat and oxidation, maintaining their viscosity and protective properties far better than conventional oils. This ensures consistent lubrication even when the engine is under heavy load. Additionally, the 4WD system, particularly the transfer case, can suffer from wear due to friction and heat. Switching to synthetic gear lube can reduce operating temperatures and extend the life of the gears and bearings, ensuring reliable engagement of four-wheel drive when needed.
By understanding the specific needs of this classic vehicle and utilizing advanced synthetic lubricants, owners can preserve the 1987 Chevrolet Blazer’s performance and longevity. Whether the vehicle is used as a daily driver or a weekend recreation vehicle, the right maintenance regimen makes a significant difference in its operational lifespan.