Engines - Troubleshooting and Maintenance Flashcards
What is the main purpose of an electronic engine control system?
To monitor and control the engine and shut it down in the event of a critical alarm without operator assistance.
This system acts as a warning or shutdown mechanism, ensuring safety during operation.
What are the common power supply voltages for electronic engine control systems?
12V, 24V, or 110 volts.
These voltages are standard for powering control systems in various engine setups.
What type of switches are typically used in electronic engine control systems?
Mechanically operated and electronically controlled switches.
This combination allows for reliable operation and integration with electronic monitoring.
Name three parameters monitored by the electronic engine control system.
- Low coolant level
- High coolant temperature
- Low oil level
These parameters are critical for maintaining engine safety and performance.
What happens if the engine control system detects low coolant level?
The engine will shut down.
This is a safeguard to prevent engine damage due to overheating.
Fill in the blank: The electronic engine control system flags the cause of the shutdown on the _______.
Control panel
True or False: The electronic engine control system can only monitor oil levels.
False.
It monitors various parameters including coolant levels, oil pressure, and engine temperature.
What is monitored regarding oil in the electronic engine control system?
- Low oil level
- Low and/or high oil pressure
- High oil temperature
These factors are essential for maintaining optimal engine lubrication and preventing damage.
What role does the engine tachometer play in the electronic engine control system?
It monitors engine speed and can trigger a shutdown if overspeed occurs.
This is important for preventing engine damage from excessive RPMs.
What aspect of the turbocharger is monitored by the electronic engine control system?
Turbocharger control and turbo boost protection.
This ensures that the turbocharger operates within safe limits.
What is indicated by the presence of onboard diagnostic sensor malfunctions?
The electronic engine control system will trigger a shutdown.
This is crucial for diagnosing issues before they lead to engine failure.
What four parameters related to engine performance are monitored by the electronic engine control system?
- Air inlet pressure
- Exhaust temperature
- Engine throttle control
- Fuel and air shutoff
These parameters are vital for optimizing engine efficiency and performance.
What type of switches are most commonly used in engine control systems?
Mechanically operated and electronically controlled switches
This type of switch combines mechanical operation with electronic monitoring for efficiency.
What would happen if an engine control system triggered on a low coolant level?
Low coolant level (shut down)
The system shuts down to prevent damage when coolant levels are too low.
What happens when high coolant temperature is detected on an engine?
Shut down
High coolant temperatures can lead to engine overheating and damage.
What does the control panel monitor regarding oil levels?
Low oil level (shut down)
Insufficient oil can lead to engine failure, prompting a shutdown.
What condition triggers a shutdown related to oil pressure?
Low and/or high oil pressure (shut down)
Abnormal oil pressure can indicate potential engine damage.
What is monitored concerning oil temperature?
High oil temperature (shut down)
Elevated oil temperatures can affect lubrication and engine performance.
What parameter relates to engine speed monitoring?
Engine over speed (shut down)
Monitoring engine speed helps prevent over-revving, which can cause engine damage.
What does turbocharger control monitor?
Turbo boost protection (shut down)
Protects the engine from excessive turbocharger boost that can cause damage.
Which parameter indicates potential mechanical issues in the engine?
Engine and compressor vibration (shut down)
Excessive vibrations can signal mechanical failure or imbalance.
What triggers a shutdown related to diagnostic sensors?
On board diagnostic sensor malfunction (shut down)
Malfunctions in diagnostic sensors can prevent proper engine operation.
What does the control panel monitor about air intake?
Air inlet pressure
Proper air inlet pressure is crucial for efficient engine combustion.
What temperature is monitored in the exhaust system?
Exhaust temperature
Monitoring exhaust temperature can indicate engine performance and efficiency.
What type of oxygen sensor should be used to determine the correct A/F ratio on a natural gas engine that is being setup?
Wideband oxygen sensor
What type of control systems are commonly used in gas fields and other installations due to lack of utility power?
Pneumatic control and safety systems
These systems are advantageous in locations where electrical access is limited.
How are most switches in pneumatic control systems activated?
Mechanically activated and pneumatically controlled
This means physical movement triggers the pneumatic system.
What powers the pneumatic control system in installations?
Clean, dry air at moderate pressures
This air is typically supplied by an engine-driven compressor.
Why is the pneumatic control system considered ideal for hazardous locations?
No sparks.
This eliminates the risk associated with electrical systems in potentially explosive environments.
Before the 1990s, what type of control panels were most engines in natural gas compressor installations equipped with?
Pneumatic control panels
These panels provided a simple and effective means of control.
What color alarms did pneumatic control panels use to indicate the status of each control?
Red or green
Red typically indicates a fault, while green indicates normal operation.
What systems did the pneumatic control system monitor?
The same systems as the electronic engine control system
This allows for a comprehensive monitoring approach regardless of the control type.
What is the primary goal of a good maintenance program?
To achieve maximum on-line availability of the engine at reasonable cost
This includes minimizing downtime and optimizing repair costs.
What type of maintenance involves performing repairs after a failure occurs?
Reactive maintenance
This approach is often less cost-effective due to unplanned downtimes.
What is preventive maintenance?
Overhauls are done based on equipment experience, planned and scheduled in advance of a major failure
This strategy aims to prevent unexpected breakdowns.
Describe predictive maintenance.
The engine is monitored regularly and work is performed when signs of a problem are detected
This includes oil analysis, coolant checks, and observing operations charts.
Which types of maintenance programs are considered the most economical?
Preventive maintenance and predictive maintenance
They have the greatest impact on machinery productivity.
What is a key factor in planning overhauls?
Consulting with a specialty company to form a plan of action
This ensures that all aspects of the maintenance are covered effectively.
What can result from well-planned overhauls?
Decreased downtime
Properly scheduled work can lead to fewer disruptions in service.
Fill in the blank: Predictive maintenance aims to achieve _____ maintenance.
maximum up time for the least amount of cost
This strategy focuses on efficiency and cost-effectiveness.
What type of maintenance program results in the most machine up-time for the least cost?
Predictive maintenance program
*this is the best maintenance program
What are some basic pressure devices that should be monitored?
- Lube oil pressure
- Jacket water pressure
- Air manifold pressure
- Crankcase pressure
Monitoring these pressures is crucial for engine safety and performance.
What additional monitoring systems are recommended for engines?
- Engine over speed systems
- Excessive vibration systems
These systems help prevent damage by alerting operators to potential issues.
What two fluid analysis systems should be included in a maintenance program for engines?
- Oil analysis
- Coolant analysis
Regular analysis helps in maintaining engine health and performance.
True or False: A spark ignition engine requires a spark at the right time.
True
Timing is critical in spark ignition engines for efficient combustion.
Fill in the blank: A compression ignition engine needs _______ to operate.
heat
Heat is essential for fuel ignition in compression ignition engines.
What two factors are required for proper ignition in a CI engine?
- Is it turning over fast enough?
- Is the fuel delivered at the correct time?
These factors are essential for engine start-up and performance.
What are the two areas of engine troubleshooting?
- Determining if the engine has the basic requirements necessary for operation
- Assessing if the mechanical state of the engine needs correction
The basic requirements for operation include air, fuel, and a source of ignition.
What are the three basic requirements all engines need to run?
- Air
- Fuel
- Source of ignition
If any of these essentials are missing, the engine will not start or run.
What are common errors in troubleshooting engines?
- Not investigating operations records
- Not using readily available information as a diagnostic tool
- Making arbitrary adjustments without fixing the real problem
These errors can lead to ineffective troubleshooting and potential damage to the engine.
What is a common initial approach to troubleshooting engines?
Random replacement of parts or adjusting balance valves on all power cylinders
This approach may not address the specific issue and can overload other engine parts.
What is necessary for effective troubleshooting?
A complete understanding of how the engine works and the resources available to diagnose the problem
Tables, charts, and manuals provide basic direction but may require additional repair work.
What tools can assist in troubleshooting modern engines?
Electronic diagnostic tools
While electronic tools can help, common sense is also important in solving engine problems.
What does blue/grey smoke from an engine indicate?
Excessive oil consumption
This suggests oil leaking into the cylinder, most often from valve seals
What does black smoke from an engine signify?
Poor A/F mixture (rich mixture) or injection timing issue
This can occur due to a malfunction in the fuel system.
What does white smoke from a diesel engine indicate?
The diesel engine is not warm
White smoke can also suggest incomplete combustion or other issues.
What could white smoke with some colour coming from an engine exhaust signify?
Coolant leaking into the cylinder;
The head gasket or some other internal component is leaking
This condition requires immediate attention to prevent further engine damage.
How often should oil and coolant levels be checked on an industrial engine?
Daily
The time of the scheduled tune up is also an appropriate time to change the oil and filters.
True or false: An engine crankcase breather must have a filter.
True
Ideally, it would be a 3µm filter.
When should the oil in an engine air cleaner (oil bath) by changed?
At the same interval as the engine oil.
Sooner, if the operating environment is dirty.
What should be added to an engine’s coolant if the levels are low?
Clean distilled water with the proper inhibitors or anti-freeze solutions
When should spark plugs be inspected or replaced?
During a scheduled tune-up
What precautions must be observed when replacing spark plugs in an engine?
Use new gaskets and torque them to the specified value
This ensures that there is a good spark plug heat path, resulting in proper cooling.
What happens to the heat path of a spark plug if it is over-torqued during installation?
The ceramic core will become unseated, resulting in a hotter spark plug
This can cause pre-ignition.
True or false: Magneto must be timed to the engine at the time of installation.
True
This is done with the aid of a widebody O₂ sensor in the exhaust manifold.
When referring to an engine ignition system, what is a capacitor discharge ignition system?
A magneto ignition system
Capacitor = condenser
What is the purpose of an engine cylinder compression test?
To check the compression of each cylinder when the spark plugs are removed
This helps identify potential engine issues.
What is the typical compression pressure range for engines?
130 psi to approximately 190 psi
Consult the engine manual for specific values.
What must be done before checking engine compression?
Warm up the engine to operating temperature
This ensures that the components are up to running temperatures for proper sealing.
When should engine cylinder compression pressures be investigated?
When the compression pressure are uneven or lower than normal.
Possible valve and seat regrinding or piston ring replacement may be needed.
When should periodic engine valve clearance adjustments be made?
At every tune-up or as the manual suggests
This is essential for engines with solid lifters.
What happens to valve clearance in industrial engines over time?
It reduces due to wear from heat and long operation
This can lead to valves that do not close completely due to valve train wear.
What can inaccurate valve clearance settings lead to?
Impaired engine performance
Too tight clearances increase the risk of burned valves.
How should the cam follower be orientated when valve clearance be set?
When the cam follower is on the base circle of the camshaft
Accurate positioning of the camshaft is crucial.
How is the correct order for setting valves determined?
Start at number one cylinder with the piston at TDC at the end of the compression stroke
Proceed in the firing order.
How can TDC be determined on a cam in block engine?
Rotate the crankshaft until both push rods of the same cylinder can be rotated by hand after the intake valve closes
This helps ensure correct valve adjustment.
What is the acceptable difference in compression readings between cylinders?
No more than 10% difference
This indicates a healthy engine.
What test can further diagnose low compression issues?
Leak down test
This test is where compressed air is added to a cylinder when it’s at TDC on the compression stroke, and observed for the pressure drop over time.
True or False: Too loose valve clearances can lead to valve head cam breakage.
True
Proper adjustments are critical to prevent engine damage.
What issue can arise on engines if the valve lash is too tight?
Burnt valves
This is because the valve face doesn’t fully seat against the valve seat, or sits there for a shorter amount of time.
What issue can arise on engines if the valve lash is too large?
The vale head can break off.
This is causes by excessive impact force due to the excessive valve travel.
What type of engine (fuel) requires the throttle held in the open position and the ignition switch in the off position during a compression test?
Natural gas engine
What are the two types of engine control systems?
- Pneumatic
- Electric
Pneumatic is no longer common.
Which meter is used to check for correct operation of high-tension wires from the coil to the spark plug?
Megger
