The 1987 Isuzu Impulse powered by the 2.0L 4-cylinder turbocharged engine represents a unique piece of automotive history, combining the spirited character of a hot hatch with a robust Japanese drivetrain. Keeping this vehicle in peak running condition requires fluids specifically formulated to handle both the demands of modern synthetic performance and the aging seals of a vehicle from the late 1980s. Proper lubrication is essential not just for protection, but for maintaining the delicate balance of a turbocharged system and ensuring longevity in a car that may see significant mileage over its decades of service.
Recommended AMSOIL Products
Based on the manufacturer’s specifications and the unique requirements of the 2.0L turbo engine, the following lubricants and filters are the top recommendations for maintaining your 1987 Isuzu Impulse.
- AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil – Provides superior protection for turbocharged engines with up to 25,000 miles of performance coverage.
- AMSOIL Extended-Life 5W-30 100% Synthetic Motor Oil – Offers extended drain intervals and enhanced cleaning power to keep older engines running smoothly.
- AMSOIL OE 5W-30 100% Synthetic Motor Oil – A cost-effective synthetic option that fights sludge and deposits while meeting OEM standards.
- AMSOIL 5W-30 100% Synthetic High-Mileage Motor Oil – Formulated with seal conditioners to reduce leaks and consumption in vehicles with over 75,000 miles.
- WIX Oil Filter – A premium filtration choice designed to capture contaminants and protect engine internals longer than standard OEM filters.
- AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Ensures smooth shifts and protects against thermal breakdown in automatic transmissions.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A 50/50 pre-mix ethylene glycol coolant that protects cooling system metals and lasts up to 150,000 miles.
- AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube – Ideal for standard rear differentials, offering protection against wear and thermal runaway.
- AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube – A high-performance gear lube for limited-slip differentials, containing friction modifiers for better traction.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Maintains pedal feel and ABS responsiveness with a high boiling point to prevent fade.
Why Engine Oil Matters for the 1987 Isuzu Impulse
The heart of the 1987 Isuzu Impulse in this configuration is the 2.0L 4-cylinder turbocharged engine. Turbocharging places unique stresses on an engine, particularly regarding heat management and oil film strength at high RPMs. The 1987 model year Impulse engine is designed to operate efficiently with a 5W-30 viscosity grade. AMSOIL synthetic motor oils are engineered to outperform conventional oils in these high-stress environments.
Using AMSOIL Signature Series 5W-30 provides the highest level of protection available, reducing horsepower loss and wear by 75% compared to industry standards. This is critical for turbochargers, which spin at extremely high speeds and require a robust oil film to prevent shaft wear. The oil also contains additives that resist coking, a common issue where oil carbonizes on the hot turbocharger bearings. For owners looking for a slightly more economical option without sacrificing synthetic benefits, the AMSOIL Extended-Life 5W-30 offers 37% more cleaning power to help remove sludge and keep the engine running smoothly. If your vehicle has accumulated significant miles, the High-Mileage 5W-30 includes seal conditioners to reduce leaks and consumption, a common occurrence in older Japanese engines as gaskets age.
The engine oil capacity for a 1987 Isuzu Impulse with the 2.0L turbo engine is 4 quarts when changing the oil filter. After refilling, it is essential to check the oil level using the dipstick to ensure the correct quantity is in the crankcase.
Transmission and Differential Care
The transmission system in the 1987 Isuzu Impulse comes in both manual and automatic variants. Proper fluid selection is vital for smooth shifting and longevity. For automatic transmissions, the Isuzu requires a fluid compatible with GM Dexron specifications. AMSOIL Signature Series Multi-Vehicle ATF is designed to withstand the rigors of heavy use, elevated temperatures, and challenging terrain while remaining fluid in sub-zero conditions. For manual transmissions, the 5-speed models require 3.4 pints of fluid. Many owners find that using AMSOIL OE 5W-30 in the manual transmission can provide excellent lubrication and shift feel, though specific manufacturer manuals should always be consulted for the primary fluid type.
The differential on the rear axle also plays a crucial role in the driving dynamics of this vehicle. For the standard rear differential, AMSOIL SEVERE GEAR 80W-90 offers advanced protection against wear and rust. If your Impulse is equipped with a limited-slip differential, it is important to use a gear lube with friction modifiers. AMSOIL SEVERE GEAR 75W-90 is specifically formulated for this purpose, ensuring that the limited-slip clutch packs engage properly without chatter or slipping. The capacity for the rear differential is typically 3.2 pints.
Cooling and Brake Systems
Maintenance of the cooling system is paramount for any vehicle, especially those with a turbocharger that generates significant heat. The 1987 Isuzu Impulse has a coolant capacity of 9.5 quarts. AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a phosphate-, nitrate-, and nitrite-free formula that is compatible with all other antifreeze colors and protects all cooling system metals, gaskets, and hoses. For those who prefer a concentrated antifreeze that requires mixing with distilled water, the AMSOIL Propylene Glycol Antifreeze offers a robust solution with exceptional corrosion protection.
Brake fluid is another critical safety component that often gets overlooked. Over time, brake fluid absorbs moisture, which can lead to corrosion in the brake lines and a spongy pedal feel. AMSOIL DOT 3 and DOT 4 Synthetic Brake Fluid is designed to provide a stable viscosity over a wide temperature range, ensuring excellent responsiveness for both ABS and traction-control systems. This fluid resists boiling under hard braking, maintaining safety and performance.
About the 1987 Isuzu Impulse
The 1987 Isuzu Impulse stands as a fascinating chapter in automotive history, representing Isuzu’s foray into the sporty compact car market that was gaining popularity in the late 1980s. Based on the Isuzu O-812 platform, the Impulse was distinct for its sleek, aerodynamic fastback design which was quite advanced for its time. The vehicle was marketed as a “hot hatch,” offering enthusiasts a compact car that delivered more than just fuel economy. It was produced by the Japanese automaker Isuzu, known for their diesel truck engines and pickup trucks, but they brought engineering precision to this passenger car line as well.
The specific variant discussed here features the 2.0-liter 4-cylinder turbocharged engine, identified by the engine code [F] F Turbo. This engine was the star of the show, delivering spirited performance that rivaled many European counterparts of the era. The turbocharger allowed a relatively small displacement engine to produce significant horsepower, providing quick acceleration and a fun driving experience. The driving character of the Impulse was characterized by responsive steering and a tight suspension setup that encouraged spirited driving. Owners of this vehicle often appreciate its handling dynamics and the unique aesthetic of its wedge-shaped body and pop-up headlights (on certain models, though the turbo model was often a liftback or hatchback design). The car was positioned as a premium compact, offering a blend of utility and sportiness that was rare in the domestic American cars of the time.
Despite its engineering merits, the 1987 Isuzu Impulse, like many vehicles from this era, has faced specific challenges as it has aged. Common issues for owners include oil consumption, which can be exacerbated by hardened valve stem seals, and turbocharger wear if the oil has not been changed frequently or with high-quality lubricants. The oil pressure can sometimes drop due to sludge buildup in the engine’s oil galleries, which a synthetic oil like AMSOIL OE can help mitigate by fighting deposits. Additionally, the cooling system can suffer from corrosion over decades, leading to overheating issues that can damage the turbocharger and the cylinder head. Using a high-performance antifreeze like AMSOIL Passenger Car & Light Truck Antifreeze helps prevent this internal corrosion and extends the life of the cooling components. Another area of concern is the transmission, particularly the clutch in manual models and the shift quality in automatics, where fluid degradation over the years can lead to harsh shifts or slipping. Finally, rust and corrosion on the undercarriage are common in older cars, and using protectants like AMSOIL Heavy-Duty Metal Protector can help preserve the vehicle’s structural integrity.
For the enthusiast or the collector, maintaining a 1987 Isuzu Impulse requires attention to detail and the use of high-quality fluids that respect the vehicle’s original specifications while adding modern synthetic benefits. Whether you are driving it regularly or keeping it for show, ensuring the right lubricants are used is the best way to preserve this unique piece of automotive history.