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Diesel Diagnostics for Gas Instructors
Jim HaldermanCurt Ward
Introductions
• Jim Halderman – The Gas guy
• Curt Ward – The Diesel guy
Topics to be discussed
• The differences between gas and diesel engines
• Care and feeding of diesels• How to begin diagnosis • Code/Monitor diagnosis• Case Studies
Differences Between Gas and Diesels
Differences Between Gas and Diesels
• Tank pump- 30-60 PSI• Fuel filter
• Tank pump- 30-60 PSI• Fuel filter (with water
separator)
What we hear
• We don’t test diesels in our area!• Why should I teach this?Because:• New diesel powered cars and light duty trucks
are one of the fastest growing segments in the industry.– Example: Volkswagen forecasts 100,000 diesel
sales in the United States for 2014
Diagnosis Basics
• Like gasoline engines, this is more about developing a process to verify, diagnose and repair a diesel engine performance concern.
Service Information
• Factory Service Information – The best– Some information is free
• Aftermarket Service Information – Also good– Examples: Alldata, Mitchell, IATN, Identifix
• Identifix free for a NATEF certified school
Vehicle and System Focus
• For this presentation we fill focus on 4-Stroke, Direct-Injection Engines with an exhaust after-treatment system
Subjects your students need to understand!
• High Pressure Common Rail Injection• Diesel Fuel• Diesel Exhaust Fluid• Diesel Motor Oil• Diesel Engine Maintenance• Customer Driving Habits• Starting Fluid Issues
High Pressure Common Rail Fuel System
• Fuel system pressures can reach as high as 30,000 PSI
• Pressures this high can inject diesel fuel directly into the skin.
• Always follow safety instructions
Ultra-Low Sulfur Fuel
• Required for use in 2007 and later engines• Maximum 15 ppm sulfur content• Allows use of exhaust after-treatment systems• Phased in starting September 2006• Feds require labels at the pump
Diesel Fuel
• Cetane – What does this mean?• Diesel Fuel Conditioning• BioDiesel• Fuel Costs
Cetane
• Measure of fuel’s ignition delay– Time between injection start and combustion
start
• Higher Cetane = Shorter delay• Opposite of Octane
Injection CombustionTime
Cetane
Diesel Fuel Conditioning
BioDiesel
• Made through process of transesterification– Glycerin separated from
fat or vegetable oil
• Leaves behind 2 products• Methyl Esters(Biodiesel)• Glycerin (used in soaps)
• Biodiesel benefits:– No sulfur or aromatics– 78.5% CO2 reduction in
production and use when compared to petrodiesel
– Renewable resource
• Biodiesel pitfalls:– Additional land usage
(agriculture)– More expensive– Higher NOx
Can I use BioDiesel?
• 2012 Volkswagen TDI• 2012 Ford F250
Fuel Costs
• Diesel used to cost less than gasoline, now it cost more; why?
• According to the United States Energy Administration "It really comes down to the fact that diesel fuel is the transportation fuel of choice outside the U.S. "It's a commodity that's in much higher demand in the rest of the world."
Diesel Exhaust Fluid (DEF)
• What is it• What is its purpose• Maintenance issues
Diesel Motor Oil
• Low Ash Motor Oil• Assists in reduction of
PM emissions• API CJ-4 oils meet low
ash specs• Required to meet
manufacturers warranty requirements
Diesel Maintenance Topics
• Fuel/Water Filters• Air Filter• Oil and Oil Service• Engine Coolant
Fuel/Water Filters
• What is the service interval?
• How many filters?• Water in fuel indicator
& Service• Failure to service costs
thousands
Air Filter
• What is the Filter Material?
• What is the Micron size of the holes?
• Filter Minder – the only way to check the filter for replacement!
Oil and Filter Service
• Correct oil?• OE Filter?• Service interval factors
– Miles– Hours– Oil life monitor
Coolant & Coolant Nitrate Service
• OE equivalant coolant?• Service Interval?• Nitrate Level?• Filter Service?
Customer Driving Habits
• Cause– Short trip driving– Long idle time
• Effect– Fuel mileage– Oil Life– Life of Particulate Filter
Starting Fluid Concerns
• Ether will dry up oil on cylinder walls making it harder to start
• Glow plug damage• Mechanical failure• Some manufactures will
allow add-on quick start systems
2007+ Diesel Emissions Changes
2006 2007 2008 2009 2010 2011 2012
PM 100% at 0.01-g/hp-hr
NOx 50% at 0.2-g/hp-hr 100% at 0.2-g/hp-hr
FUEL 80% at 15 PPM MAXIMUM SULFUR (UNDER VOLUNTARY
COMPLIANCE OPTION)
100% at 15 PPM
Exhaust System (after treatment)
Diesel Oxidation Catalyst
• Reduce Carbon Monoxide by up to 85%• Reduce Hydrocarbons by up to 60%• Reduces Particulate Matter by up to 20%
NOx Adsorber Catalyst (SCR)
• Diesel Exhaust Fluid (ammonia) with the catalyst reduces Oxides of Nitrogen into the natural elements of Nitrogen and water
Particulate Filter (DPF)
• Wall-flow design• Filters, stores, burns
particulate matter• PM oxidized into CO2 at
600 degrees F• Ash residue will remain
in DPF• Will require service
eventually
Typical No Code Concerns
• No Start• Hard/ Slow Start/
Extended Crank• Misfire/Runs Rough/
Lacks Power
Check the Oil!
• Oil level and condition can tell a LOT• If overfilled= diesel fuel in the oil• If low/dirty= Ford 7.3 and 6.0 Liter engines
may run rough/not run because it the engine oil under high pressure that opens the injectors.
No Start
• Aftermarket Anti-Theft Devices
• Charge Air Cooler Concerns
• Fuel Pressure and Delivery Concerns
• Fuel Quality Concerns
Hard-Slow Start/ Extended Crank
• Battery & Charging System Concerns• Fuel Quality and Delivery Issues• Glow Plug/ Intake Heater Concerns
Misfire/ Runs Rough/ Lacks Power
• Engine Mechanical Concerns• Fuel Delivery Issues• EGR• Turbocharger Concerns• Air Induction Problems• Engine Operating Temperature• Oil Pressure
Fuel Pressure DiagnosisCommon Rail Systems
• Low pressure system• Return Volume• High Pressure delivery
Low Pressure(example Dodge)
Fuel Return(example Dodge)
High Pressure(Scan Tool Only)
High Pressure Fuel Test
Code Diagnostics
• Scan tool information varies from vehicle to vehicle and from tool to tool.
• No one tool good for all vehicles (just like gas)• Factory scan tools are the best
Diesel OBDII Diagnostic Requirements
• What does it take to set the code• When is it monitored• What are the requirements to make the
monitor ready to run and then run after the repair process is complete to confirm diagnosis and repair
Diesel OBDII Monitors(As equipped)
• NMHC Catalyst• NOx Catalyst• Misfire• Fuel System• Upstream Exhaust Gas
Sensor• Downstream Exhaust Gas
Sensor• NOx Sensor #1• Cold Start Strategy• VVT System
• NOx Sensor #2• PM Sensor• EGR• EGR Cooler• Boost Pressure• Charge Air Cooler• NOx Adsorber• PM Filter• Crankcase Ventilation• Engine Cooling System
Monitor Example(Snap-On Scan Tool)
Monitor Example(Factory Scan Tool)
Case Study #1
• 2010 Ford Truck, 6.4L Engine • 10,456 Miles• MIL On and Lacks Power on Acceleration• Code P2463 Particulate Filter – Soot
Accumulation• Perform Manual DPF Regeneration & Clear
Code• Concern caused by extended idle
Case Study #2
• 2012 Ford Truck 6.7L with 19,852 Miles• No Power, MIL and Maintenance Lights On• Code P204F – Reductant System Performance• Found Diesel Exhaust Fluid Reservoir empty• Filled Reservoir with proper fluid & cleared
code• Cause: Failure to heed warning lamps
Diesel Emission Testing
• Growing number of states testing• Select areas of testing within these states• Testing typically classified by vehicle weight
(GVWR)• Processes include visual inspection, smoke
opacity, and OBDII• Many of the same exemptions as gasoline
powered vehicles
Aftermarket Programmers
• Primary use to increase torque and horsepower
• Typically change fuel delivery
• May have a negative effect on drivetrain
• May cause emissions failure at test lane
So I am interested in creating a diesel class or adding the topic to my program
• Resources– ASE A9 task list– NATEF (medium truck) task list– James Halderman @ www.jameshalderman.com– Sonny Reeves AYES@ www.autoteacher.net– Rick Escalambre @ http://rlescalambre.com/– Automotive Diesel Technology: Gus Wright,
Pearson Publishing
Summary
• Diesel is rapidly becoming a major player ($) in the aftermarket repair business.
• Many similarities with GDI • Addition of this topic to most programs will
enhance the students ability to earn ($) upon completion.
Clear Highways
• We hope to see you at NACAT 2014
• Thanks for attending
• Don’t forget to thank our hosts
