1986 Mack Engine Manual

The 1986 Mack Engine Manual provides comprehensive technical information for Mack E6 and E7 series diesel engines manufactured in 1986. This manual covers engine specifications, maintenance procedures, troubleshooting, repair guidelines, and operational instructions for these heavy-duty commercial engines. Below are key sections for specifications, maintenance schedules, operation, troubleshooting, and repair procedures.

Engine Specifications

Technical specifications for 1986 Mack E6 and E7 series diesel engines.

Specification	Description
Engine Model	E6-275, E6-300, E7-300, E7-350
Displacement	E6: 672 cu in (11.0L), E7: 728 cu in (11.9L)
Configuration	Inline 6-cylinder, 4-stroke diesel
Bore x Stroke	E6: 5.00" x 5.75", E7: 5.25" x 5.75"
Compression Ratio	16.0:1
Horsepower Range	275-350 HP
Torque Range	1050-1350 lb-ft
Fuel System	Mack mechanical injection pump
Governor Type	All-speed mechanical
Weight (Dry)	Approx. 2100-2300 lbs

Maintenance Procedures

Regular maintenance schedule and procedures for optimal engine performance.

1. Oil Change: Every 15,000 miles or 500 hours - Use 15W-40 diesel oil
2. Fuel Filter Replacement: Every 30,000 miles - Replace primary and secondary filters
3. Air Filter Service: Check every 15,000 miles, replace as needed
4. Coolant Change: Every 2 years or 100,000 miles
5. Valve Adjustment: Every 50,000 miles or 1,500 hours
6. Injector Timing: Check every 100,000 miles

WARNING! Always allow engine to cool before performing maintenance. Use proper safety equipment.

Operation Guidelines

Proper engine operation procedures and monitoring.

1. Pre-start Inspection: Check oil level, coolant level, and belt tension
2. Cold Start Procedure: Use glow plugs for 15-30 seconds before cranking
3. Warm-up Period: Allow 3-5 minutes at low idle before loading
4. Operating Temperatures: Coolant 180-195°F, Oil 210-230°F
5. Shutdown Procedure: Allow 3-5 minutes at low idle before shutting down
6. Daily Checks: Monitor gauges for abnormal readings

CAUTION! Do not operate engine with low oil pressure or high coolant temperature.

Fuel System

• Injection Pump: Mack mechanical rotary pump with mechanical governor
• Injectors: Multi-hole pintle type, opening pressure 2100-2200 psi
• Fuel Filters: Primary and secondary spin-on filters
• Fuel Pressure: 45-65 psi at injection pump inlet
• Injection Timing: 18° BTDC static timing
• Fuel Specifications: #2 diesel fuel, minimum cetane rating 40

Cooling System

Cooling system components and maintenance requirements.

Components: Belt-driven centrifugal water pump, thermostat (180°F), radiator, fan clutch.

Coolant Capacity: 8-10 gallons (with heater). Coolant Type: Ethylene glycol with SCA additives. System Pressure: 13-15 psi cap. Fan Engagement: Viscous clutch engages at 195°F.

Lubrication System

Oil system specifications and maintenance procedures.

1. Oil Capacity: 10-12 quarts (including filter)
2. Oil Pressure: 40-60 psi at operating temperature
3. Oil Filter: Spin-on full flow filter
4. Oil Type: API CD/SF 15W-40
5. Oil Change Interval: 15,000 miles or 500 hours

Tip: Always check oil level when engine is cold and on level surface.

Electrical System

Electrical specifications and component information.

1. Starting System: 12V negative ground, 8-10 HP starter motor
2. Charging System: 75-100 amp alternator, internal regulator
3. Batteries: Two 12V batteries in parallel
4. Glow Plugs: 12V ceramic type, 15-30 second pre-heat
5. Sensors: Coolant temperature, oil pressure, turbo boost
6. Wiring: Color-coded harness with weatherproof connectors

WARNING! Disconnect batteries before working on electrical system.

Troubleshooting

Common engine problems and diagnostic procedures.

Symptom	Possible Cause	Corrective Action
Hard Starting	Weak batteries, glow plug failure	Check battery voltage, test glow plugs, verify fuel delivery
Low Power	Fuel restriction, turbo issues	Check fuel filters, inspect turbocharger, verify injection timing
Excessive Smoke	Injection timing, air restriction	Check injection timing, inspect air filter, verify turbo operation
Overheating	Coolant level, thermostat	Check coolant level, test thermostat, inspect water pump
Oil Consumption	Worn rings, valve guides	Perform compression test, inspect valve guides

Repair Procedures

Step-by-step repair instructions for common engine components.

1. Injector Replacement: Remove valve cover, disconnect lines, replace injectors
2. Water Pump Replacement: Drain coolant, remove belts, replace pump
3. Turbocharger Service: Inspect for shaft play, replace if excessive
4. Head Gasket Replacement: Remove head, clean surfaces, install new gasket
5. Oil Pump Replacement: Remove oil pan, replace pump and drive gear

CAUTION! Use proper torque specifications and sequence for all fasteners.

Safety Information

Important safety precautions when working on Mack engines.

Always disconnect batteries before service. Use jack stands when working underneath. Wear safety glasses and gloves. Avoid contact with hot surfaces. Use proper lifting equipment for heavy components. Follow all lockout/tagout procedures.

Technical Support

Mack Trucks, Inc. customer support and service information.

For technical assistance, contact Mack Customer Center at 1-800-866-1177. Parts and service available through authorized Mack dealers nationwide. Technical bulletins and updates available from Mack corporate website. Copyright © 1986 Mack Trucks, Inc. All rights reserved.