AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 1 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems AURT304666A Repair and replace emission control systems AUR30405 CERTIFICATE III IN AUTOMOTIVE MECHANICAL TECHNOLOGY

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 2 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Personal safety Use personal protective equipment (PPE). Use wheel chocks & guard covers. Keep clear of hot or moving components on engines. Lift vehicles correctly and safely. Plenty of ventilation when working on running engines.

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 3 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Forms of pollution Pollution from evaporationPollution from combustion

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 4 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Producing exhaust gases Air enters the engine Fuel is injected into the engine Combustion Blow by Exhaust gas exits the engine

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 5 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Sources of emissions Fuel tanks and carburettors 10% by evaporation Crankcase 30% from combustion and blow by Exhaust 60% from combustion

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 6 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Emissions from petrol engines Hydrocarbons (HC) come from: unburnt fuel evaporating fuel crankcase vapours or blow by gases

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 7 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Emissions from petrol engines Carbon monoxide (CO) comes from: incomplete combustion due to a lack of oxygen(air) during combustion excessively rich fuel/air mixtures very lean fuel/air mixtures

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 8 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Emissions from petrol engines Oxides of nitrogen (NOx) come from: overheating engine conditions increased compression ratios incorrect ignition timing lean fuel mixtures.

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 9 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Guidelines for 6 tests: 1.Exhaust emissions after a cold start. 2.Carbon monoxide emission test at idling speed. 3.Emissions of crankcase gases. 4.Evaporative emissions from vehicles with positive-ignition engines. 5.Endurance test for durability of pollution control devices. 6.Average exhaust emissions of carbon monoxide and hydrocarbons after a cold start at low ambient temperature. Government legislation

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 10 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Emissions from diesel engines Particulates carbon particles in the exhaust gas formed due to: –incomplete combustion –slow and cold engine operation –high engine oil consumption. Oxides of nitrogen (NOX) formed due to high combustion temperatures in diesel engines.

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 11 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Government legislation National Environment Protection Measure (Diesel Vehicle Emissions) 2001, amended in

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 12 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Types of emission control systems 3. Exhaust emission control Controls the products of combustion before they enter the atmosphere 2. Crankcase ventilation Prevents crankcase emissions escaping to the atmosphere 1. Evaporative control Prevents fuel vapour escaping to the atmosphere

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 13 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Evaporative emission control system Carburettor Charcoal canister Vapour line to canister Liquid/valve separator Fuel tank Petrol cap relief valve Vapour vent Fuel line Purge line Air vent solenoid valve

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 14 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Evaporative emission control system Seals the fuel tank and carburettor. Temporarily stores the fuel vapour. Regularly flushes out the stored fuel vapour. Stops fuel vapour escaping into the atmosphere:

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 15 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Charcoal Canister Stores the evaporating fuel from the tank and carburettor (if fitted). When the engine starts the stored fuel vapour is sent to the engine. Fuel vapour line from carburettor Charcoal Filter Air vent Fuel vapour line from tank Throttle ported vacuum Line to intake manifold

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 16 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Fuel tank and cap Stores the fuel. Prevents the fuel vapour from escaping to the atmosphere. Fuel tank Fuel filler cap Liquid vapour separator

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 17 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Crankcase ventilation system PCV - Positive Crankcase Ventilation valve Prevents excessive pressure build up in the crankcase. Prevents unburnt fuel vapour from escaping to the atmosphere. Fresh air inlet Blowby gases Crankcase vapours & blowby gases PVC valve Intake manifold Air filter Valve seat Valve face Valve spring Shuttle valve Retaining spring Valve housing Hose connection to inlet manifold

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 18 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Exhaust emission control systems Exhaust gases = more than 1/2 total emissions from vehicles. Three ways to reduce or control exhaust emissions: 1.Engine design 2.Exhaust Gas Recirculating system (EGR) 3.Catalytic converter.

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 19 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Engine design Wedge shaped combustion chamber large quench area increased hydrocarbon emissions Hemispherical combustion chamber minimal quench area less hydrocarbon emissions

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 20 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Exhaust Gas Recirculating system (EGR) Returns some exhaust gas to intake manifold. Lowers combustion temperature. Reduces oxides of nitrogen (NOx) in exhaust gas. Exhaust gas port Thermo valve ERG valve Vacuum port

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 21 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Catalytic Converter Fitted to the vehicle exhaust system as close as possible to the engine. Tailpipe Muffler to tailpipe Muffler Pipe to muffler Catalytic convertor Engine pipe

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 22 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Pollutants from engine Catalytic Converter To exhaust HC - Hydrocarbons CO - Carbon monoxide NOx - Oxides of nitrogen H 2 O - Water CO 2 - Carbon dioxide O 2 - Oxygen N - Nitrogen Chemicals react with pollutants in exhaust gas

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 23 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Diesel particulate filter Exhaust carrying particulate matter (PM) enters open channels. Ends of channels are blocked forces exhaust through walls. Pm is captured on the walls over time, pm burns away. Exhaust in Clean exhaust out Soot and ash particles

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 24 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Emission Control Information label 2005 ADR) 79/02 emission control regulations. Must be in a visible position in the vehicle engine compartment. Must state a range of engine specifications and adjustments.

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 25 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems Testing exhaust emissions Measure pollutants in exhaust gases with an exhaust gas analyser Good ventilation is critical when testing

AURT A REPAIR AND REPLACE EMISSION CONTROL SYSTEMS 26 © Commonwealth of Australia 2011AURT A Repair and replace emission control systems © Commonwealth of Australia 2011 ISBN: This document is available under a “Free for Education” licence for educational purposes – see for details. This work is copyright. You may download, display, print and reproduce this material in whole or in part or in modified form (retaining this notice) for your personal, non-commercial use or use within your organisation. If you use, display, or reproduce this material or a modified form of it in whole or in part within your organisation you must include the following words in a prominent location within the material in font not less than size 12: ‘The views expressed in this publication do not necessarily represent the view of the Minister for Education or the Australian Government. The Australian Government does not give any warranty nor accept any liability in relation to the contents of this work’. Apart from any use as permitted under the Copyright Act 1968, all other rights are reserved. Requests and inquiries concerning reproduction and rights should be addressed to the Commonwealth Copyright Administration, Attorney General’s Department, Robert Garran Offices, National Circuit, Barton ACT 2600 or posted at Funded under the Workplace English Language and Literacy (WELL) Program by the Australian Government Department of Education, Employment and Workplace Relations. The views expressed in this publication do not necessarily represent the view of the Minister for Education or the Australian Government. The Australian Government does not give any warranty nor accept any liability in relation to the contents of this work.