## PowerTech 6.8L 6068 Compressed Natural Gas Engine

The PowerTech 6.8L 6068 Compressed Natural Gas Engine is a state-of-the-art engine that offers exceptional performance, efficiency, and environmental friendliness. Designed for heavy-duty applications, this engine delivers unparalleled power and torque while adhering to the most stringent emissions standards.

### Advanced Engine Architecture

The PowerTech 6.8L 6068 engine is built upon an advanced engine architecture that incorporates the latest technological advancements. Its robust design ensures durability and longevity even under the most demanding operating conditions. The engine features a high-strength cast iron block and cylinder heads, providing exceptional rigidity and thermal management.

### Precise Fuel Injection System

To optimize combustion efficiency and minimize emissions, the PowerTech 6.8L 6068 engine utilizes a sophisticated fuel injection system. This system precisely controls the delivery of compressed natural gas into the combustion chambers, ensuring optimal air-fuel ratios for maximum power output and fuel economy.

### Turbocharged and Intercooled Performance

For enhanced performance and responsiveness, the PowerTech 6.8L 6068 engine is equipped with a turbocharger and intercooler. The turbocharger increases airflow into the engine, boosting power and torque. The intercooler effectively reduces the temperature of the compressed air, resulting in increased air density and further enhancing performance.

### Variable Valve Timing (VVT)

The engine incorporates Variable Valve Timing (VVT) technology, which dynamically adjusts the timing of the intake and exhaust valves. By optimizing valve timing based on engine load and operating conditions, VVT enhances performance, improves fuel economy, and reduces emissions.

### Advanced Emissions Control

The PowerTech 6.8L 6068 engine meets the most stringent emissions regulations, including EPA Tier 4 Final and CARB on-road requirements. It is equipped with a suite of emissions control technologies, such as cooled exhaust gas recirculation (EGR) and a diesel oxidation catalyst (DOC), which effectively reduce harmful pollutants.

### Fuel Flexibility

In addition to operating on compressed natural gas, the PowerTech 6.8L 6068 engine also offers fuel flexibility. It can be seamlessly converted to run on diesel fuel, providing operators with the versatility to meet changing fuel availability and infrastructure needs.

### Applications

The PowerTech 6.8L 6068 Compressed Natural Gas Engine is ideally suited for various heavy-duty applications, including:

- On-road trucks
- Off-road construction equipment
- Marine vessels
- Power generation

Illustrated Factory Repair Component Technical Manual for PowerTech 6.8L, 6068 Compressed Natural Gas Engine

This manual contains high quality images, circuit diagrams, instructions to help you to operate, maintenance, diagnostic, and repair your truck. This document is printable, without restrictions, contains searchable text, bookmarks, crosslinks for easy navigation.

Language: English
Format: PDF, 485 pages

Covered models:
  6068CNG

Contents:
   Foreword
   About This Manual
   Safety
      Handle Fluids Safely-Avoid Fires
      Handle Natural Gas Safely
      Prevent Battery Explosions
      Prepare for Emergencies
      Prevent Acid Burns
      Avoid High-Pressure Fluids
      Wear Protective Clothing
      Service Machines Safely
      Work in Ventilated Area
      Work in Clean Area
      Remove Paint Before Welding or Heating
      Avoid Heating Near Pressurized Fluid Lines
      Illuminate Work Area Safely
      Use Proper Lifting Equipment
      Practice Safe Maintenance
      Use Proper Tools
      Dispose of Waste Properly
      Handle Compressed Natural Gas (CNG) Safely
      Service Compressed Natural Gas (CNG) Systems Safely
      Protect Against High Pressure
      Protect Against Extremely Cold CNG Leakage
      Live With Safety
   General Information
      Unified Inch Bolt and Cap Screw Torque Values
      Metric Bolt and Cap Screw Torque Values
      Engine Model Designation
      Engine Serial Number Plate Information
   Fuels, Lubricants, and Coolant
      Natural Gas Recommendations
      Natural Gas Engine Oil
      Engine Break-In Oil
      Alternative and Synthetic Lubricants
      Mixing of Lubricants
      OILSCANOILSCAN is a trademark of Deere & Company. and CoolScanCoolScan is a trademark of Deere & Company.
      Grease
      Recommended Engine Coolant
      Engine Coolant Specifications
      Testing Diesel Engine Coolant
      Replenishing Supplemental Coolant Additives (SCAs) Between Coolant Changes
      Operating in Warm Temperature Climates
      Flush and Service Cooling System
      Disposing of Coolant
   Engine Mounting
      Engine Repair Stand
      Safety Precautions
      Install Adapters on Engine Repair Stand
      Engine Lifting Procedure
      Clean Engine
      Disconnect Turbocharger Oil Inlet Line
      Mount Engine on Repair Stand
      Engine Mounted on Repair Stand
   Engine Rebuild Guide
      Engine Disassembly Sequence
      Sealant Application Guidelines
      Engine Assembly Sequence
   Cylinder Head and Valves
      Special or Essential Tools
      Service Equipment and Tools
      Other Material
      Cylinder Head and Valves Specifications
      Check and Adjust Valve Clearance
      Measure Valve Lift
      Remove Cylinder Head
      Disassemble and Inspect Rocker Arm Shaft Assembly
      Assemble Rocker Arm Assembly
      Inspect, Measure, and Assemble Camshaft Followers
      Measure Valve Recess in Cylinder Head
      Preliminary Cylinder Head and Valve Checks
      Remove Valve Assembly
      Inspect and Measure Valve Springs
      Inspect Valve Rotators
      Clean Valves
      Inspect and Measure Valves
      Grind Valves
      Inspect and Clean Cylinder Head
      Check Cylinder Head Flatness
      Measure Cylinder Head Thickness
      Clean Valve Guides
      Measure Valve Guides
      Knurl Valve Guides
      Clean and Inspect Valve Seats
      Grind Valve Seats
      Remove Valve Seat Inserts
      Measure Valve Seat Bore in Cylinder Head
      Install Valve Seat Inserts
      Install Valves
      Inspect and Clean Exhaust Manifold
      Clean and Inspect Top Deck of Cylinder Block
      Measure Cylinder Liner Standout (Height Above Block)
      Install Cylinder Head and Cap Screws
      Torque-Turn Method for Proper Torque
      Install Rocker Arm Assembly
      Inspect and Clean Ventilator Outlet Hose
      Install Rocker Arm Cover
      Complete Final Assembly
      Perform Engine Break-In
   Cylinder Block, Liners, Pistons, and Rods
      Special or Essential Tools
      Service Equipment and Tools
      Other Material
      Cylinder Block, Liners, Pistons, and Rods Specifications
      Connecting Rods-General Information
      Remove Pistons and Connecting Rods
      Remove Cylinder Liners
      Complete Disassembly of Cylinder Block (If Required)
      Preliminary Liner, Piston and Rod Checks
      Disassemble Piston and Rod Assembly
      Clean Pistons
      Visually Inspect Pistons
      Clean Cylinder Liners
      Visually Inspect Cylinder Liners
      Check Piston Ring Groove Wear
      Measure Piston Pin Bore
      Measure Piston Skirt
      Determine Piston-to-Liner Clearance
      Deglaze Cylinder Liners
      Replace Piston and Liner Sets
      Inspect and Measure Connecting Rod Bearings
      Inspect Rod and Cap
      Inspect Piston Pins and Bushings
      Remove Piston Pin Bushing
      Clean and Inspect Connecting Rod Pin Bore
      Install Piston Pin Bushing in Connecting Rod
      Measure Rod Center-to-Center Bores
      Inspect and Clean Cylinder Block
      Clean Cylinder Liner O-Ring Bore
      Measure Cylinder Block Main Bearing Bore
      Measure Camshaft Follower Machined Bore in Block
      Measure Camshaft Bushing Bores in Block
      Measure Liner Flange Counterbore Depth in Block
      Measure Liner Flange Thickness
      Measure Cylinder Block Top Deck Flatness
      Remove, Inspect, and Install Piston Cooling Orifices
      Measure Cylinder Liner Standout (Height Above Block)
      Install Packing on Cylinder Liner and O-Rings in Block
      Install Cylinder Liner in Block
      Assemble Connecting Rods onto Piston
      Install Piston Rings
      Connecting Rods-General Information
      Install Piston and Rod Assembly
      Torque-Turn Connecting Rod Cap Screws
      Check Engine Rotation for Excessive Tightness
      Measure Piston Protrusion
      Complete Final Assembly
   Crankshaft, Main Bearings, and Flywheel
      Special or Essential Tools
      Service Equipment and Tools
      Other Material
      Crankshaft, Main Bearings, and Flywheel Specifications
      Crankshaft Grinding Specifications
      Crankshaft and Main Bearing Failure Analysis
      Inspect Vibration Damper
      Remove Pulley or Vibration Damper and Pulley
      Install Pulley or Vibration Damper Pulley
      Checking Vibration Damper or Pulley
      Replace Front Crankshaft Oil Seal and Wear Sleeve (Without Removing Timing Gear Cover)
      Check Crankshaft End Play
      Inspect Flywheel
      Remove Flywheel
      Replace Flywheel Ring Gear
      Install Flywheel
      Crankshaft Rear Oil Seal and Wear Sleeve Handling Precautions
      Remove Unitized (Non-Separable) Crankshaft Rear Oil Seal and Wear Sleeve
      Install Crankshaft Rear Oil Seal and Wear Sleeve
      Remove Flywheel Housing
      Remove Crankshaft Main Bearings
      Check Main Bearing Oil Clearance
      Remove and Install Crankshaft Gear (Crankshaft Installed In Engine)
      Remove Crankshaft
      Inspect Crankshaft
      Measure Assembled Main Bearing ID and OD of Crankshaft Main Journal and Rod Journal
      Measure Main Thrust Journal Width and Thrust Bearing Width
      Crankshaft Grinding Guidelines
      Measure Assembled ID of Main Bearing Caps
      Remove, Inspect, and Install Piston Cooling Orifices
      Install Main and Thrust Bearing Inserts in Block
      Install Crankshaft
      Install Flywheel Housing
      Complete Final Assembly
   Camshaft and Timing Gear Train
      Special or Essential Tools
      Service Equipment and Tools
      Other Material
      Camshaft and Timing Gear Train Specifications
      Measure Valve Lift
      Remove Timing Gear Cover
      Remove and Install Camshaft Bushing With Front Plate Installed
      Measure Camshaft End Play
      Measure Idler Gear End Play
      Measure Timing Gear Backlash
      Remove Camshaft
      Visually Inspect Camshaft
      Measure Camshaft Thrust Plate Clearance
      Inspect and Measure Camshaft Bushing ID and Journal OD
      Measure Camshaft Lobe Height
      Remove and Install Camshaft Gear
      Inspect Camshaft Followers
      Remove Cylinder Block Front Plate
      Measure Idler Gear Bushing and Shaft
      Remove and Install Idler Gear Bushing
      Remove Lower and Upper Idler Shafts
      Clean and Inspect Front Plate
      Install Idler Shaft Spring Pins
      Install Upper Idler Shaft in Front Plate
      Install Lower Idler Shaft in Front Plate
      Install Engine Front Plate
      Install and Time Camshaft
      Clean and Inspect Timing Gear Cover
      Install Timing Gear Cover
      Install Crankshaft Front Wear Sleeve and Oil Seal
      Complete Final Assembly
   Lubrication System
      Special or Essential Tools
      Service Equipment and Tools
      Other Material
      Lubrication System Specifications
      Diagnosing Lubrication System Malfunctions
      Remove, Inspect, and Install Oil Filter Base
      Remove, Inspect, and Install Oil Cooler
      Remove, Inspect, and Install Oil Bypass Valve
      Remove and Install Oil Pressure Regulating Valve and Seat
      Remove and Install Oil Fill Tube
      Remove and Install Dipstick Tube With Oil Pan Installed
      Replace Oil Pump Pick-Up Tube Assembly
      Engine Oil Pump Assembly
      Remove Engine Oil Pump
      Inspect and Measure Clearances
      Complete Oil Pump Disassembly
      Assemble Engine Oil Pump
      Install Engine Oil Pump
      Install Oil Pan
   Cooling System
      Special or Essential Tools
      Service Equipment and Tools
      Other Material
      Cooling System Specifications
      Diagnosing Cooling System Malfunctions
      Remove Water Manifold/Thermostat Cover and Thermostat
      Test Thermostat
      Install Water Manifold/Thermostat Cover and Thermostat
      Remove Water Pump
      Water Pump Assembly
      Disassemble Water Pump
      Inspect, Clean, and Measure Water Pump Parts
      Assemble Water Pump
      Install Water Pump
      Remove and Install Automatic (Spring) Belt Tensioner
      Checking Belt Tensioner Spring Tension and Belt Wear
      Remove and Inspect Idler Pulley Assembly
      Replace Bearing in Idler Pulley Assembly
      Install Idler Pulley Assembly
      Remove and Install Coolant Heater
   Air Intake and Exhaust System
      Other Material
      Air Intake and Exhaust System Specifications
      Extending Turbocharger Life
      Remove Turbocharger
      Turbocharger Failure Analysis
      Turbocharger Seven-Step Inspection
      Perform Axial Bearing End Play Test
      Repair Turbocharger
      Clean and Inspect Turbine and Compressor Housings
      Adjust Turbocharger Wastegate Actuator
      Prelube Turbocharger
      Install Turbocharger
      Cleaning PCV Orifice
      Remove, Inspect, and Install Exhaust Manifold
      Remove, Inspect, and Install Intake Manifold
   Fuel Supply System
      Specifications
      Fuel Pressure Leak-Off Procedure
      Leak Check Procedure
      Remove and Install Natural Gas Regulator
      Repair Natural Gas Regulator
      Remove and Install Fuel Metering Valve
      Repair Fuel Metering Valve
      Remove and Install Fuel Mixer
   Starting and Charging System
      Special or Essential Tools
      Specifications
      Remove and Install Starter
      Bench Test Starting Motor
      Make Solenoid Return Test
      Make No Load Test
      Diagnose No Load Test
      Remove and Install Alternator
      Charging System Failure
      Alternator Troubleshooting
      Alternator Output Test
      Diode Trio Test
      Full Field Test
   Electronic Engine Controls
      Special or Essential Tools
      Service Equipment and Tools
      Other Material
      Specifications
      Remove and Install Spark Plugs
      Removal of Seized Spark Plugs (Tool JDG1193 Not Available or Spark Plug Ceramic Stem Has Broken Off)
      Remove and Install Ignition Coils
      Remove and Install Ignition Control Unit (ICU)
      Remove and Install Cam Sensor
      Remove and Install Crank Sensor
      Remove and Install Engine Coolant Temperature (ECT) Sensor
      Remove and Install Foot Pedal Position Sensor
      Remove and Install Manifold Absolute Pressure (MAP) Sensor
      Remove and Install Manifold Air Temperature (MAT) Sensor
      Remove and Install Natural Gas Tank Temperature (NGTT) Sensor
      Remove and Install Preturbine Pressure (PTP) Sensor
      Remove and Install Exhaust Back Pressure (EBP) Sensor
      Remove and Install Electronic Throttle and Throttle Position Sensor
      Remove and Install Universal Exhaust Gas Oxygen (UEGO) Sensor
      Remove and Install Oil Pressure Switch
      Remove and Install Turbocharger Wastegate Control Valve
      Natural Gas Engine Wiring Harness
      Natural Gas Engine Component Location Diagram
      Connectors
      Using High-Pressure Washer
      Replace WEATHER PACK WEATHER PACK is a trademark of Packard Electric. Connector
      Install WEATHER PACK WEATHER PACK is a trademark of Packard Electric. Contact
      Remove Connector Body from Blade Terminals
      Replace (Pull Type) METRI-PACK METRI-PACK is a trademark of Packard Electric. Connectors
      Replace (Push Type) METRI-PACK METRI-PACK is a trademark of Packard Electric. Connectors
      Use Electrical Insulating Compound
      Replace DEUTSCH DEUTSCH is a trademark of the Deutsch Co. Connectors
      Install DEUTSCH DEUTSCH is a trademark of the Deutsch Co. Contact
   Miscellaneous Accessories
      Other Material
      Miscellaneous Accessories Specifications
      Remove Air Compressor
      Inspecting Air Compressor
      Remove Idler Housing
      Install Idler Housing
      Install Air Compressor
   Dealer Fabricated Tools
      Dealer Fabricated Tools
      DFRG3 Cylinder Liner Holding Fixture