All too often, by the time a vehicle gets to our service workshop it’s because a small noise has become unbearably loud; a misfire has made the car undriveable or, a warning light that alerted a diagnostic issue before the car started to fail was ignored for too long… so, knowing what your little tell-take signs are and acting on them immediately is the same as preventing a small wound from being infected.
Here are the most common ones:
1. Car ‘Hesitates’ or ‘Stutters’ whilst cruising indicates a Misfire
Spark-plugs are electrically tuned to fire at precise timing to deliver power from the engine. If the spark fires at the incorrect time or not at all, it is considered a misfire. Misfiring of a cylinder can happen for numerous reasons. Here are the most common causes:
• Carbon or oil fouled sparkplugs – (Bear in mind that oil of carbon fouled plugs can be the result of a more serious issue with the engine)
• Perished spark-plug leads
• Bad fuel delivery – eg bad or dirty injectors, cracked intake plenum, new injector driver or flash programming of ECM (Engine Control Module) needed
• Vacuum leak
• Mechanical breakdown: Broken valve spring, burnt valve, broken or burned piston or piston ring, blown cylinder head gasket
What to do? The best way to avoid an engine misfire is to adhere to scheduled servicing. Get an annual fault-code scan done at DV Automotive and uncover any potential problems before they become major
2. Evaporative Emissions Leak and/or Failure
The evaporative emissions system control (EVAP) system is designed to trap gas tank fumes. The system consists of the fuel tank, vapor lines, liquid vapor separator to prevent liquid gasoline from entering the system and the EVAP Canister, which has a purge valve on it. Fumes are trapped inside the canister, which is full of activated carbon. At times during engine operation, the canister purge valve opens up letting fresh air into the canister. This in turn forces the trapped gas fumes back into the engine’s air intake and thus burned inside the engine.
Should the system develop a leak as a result of corrosion eating the lines or a compromised canister, the system will throw an “EVAP Leak” code in the computer. To fix the problem, one has to find the leak, or faulty component, fix or replace it, and reset the system.
What do do? To keep EVAP Systems operation properly, always make sure you tightly re-install your gas cap after refueling. In addition, a good rust protection application helps to keep system line corrosion to a minimum.
3. System Running Too Lean
If a “System Too Lean” code comes up, it’s usually due to a vacuum leak, faulty injector driver, bad injector or a software update needed. The performance computer monitors engine operating elements such as coolant and air intake temperatures, amount of airflow into the engine, throttle position, etc. If the problem-code pops up, it’s because one of these areas is compromised. DV Automotive diagnostic equipment can scan the system, identify where the malfunction exists and repair it. Typical causes of lean conditions range from a bad vacuum line, faulty sensor, broken engine gasket to a cracked cylinder head, faulty intake plenum, warped throttle body, and many other factors that can be picked up via electronic diagnostics in our motor servicing garage in Melbourne’s East.
4. Catalytic Converter Failure
Catalytic Converters fail for two reasons: either because of a leak from rust and corrosion setting in, or internal plugging from excessive carbon buildup or collapsed baffle or catalyst. The catalytic converter is a device that burns up any unburned gas in the engine exhaust, cleaning the tailpipe emissions. Problems crop up when more unburned gas is fed into the catalytic converter than it can process. The catalytic converter becomes clogged as a result of too much gas being fed into it. The clog takes the form of solidified carbon that forms inside the cat, causing a restriction of exhaust gas flow.
The only way to restore the system to proper operation is to replace the catalytic converter. However the new catalytic converter will come up with the same problem just a few months later if the cause of the problem is not rectified.
What to do? To avoid catalytic converter problems, keep the your engine finely tuned by keeping up with scheduled vegicle maintenance, tune-ups and system maintenance per factory recommendations in your manual.
5. Exhaust Gas Recirculation (EGR) System Failure
EGR stands for Exhaust Gas Recirculation. This is an emissions system designed to lower combustion chamber temperatures in order to lower formation of NOx (Oxides of Nitrogen) gas, which contributes to harmful air pollutants.
Because of the system’s very nature (feeding exhaust gas), it is highly susceptible to carbon (unburned gas) buildup, plus electronic control problems. EGR Valve complications arise from wear of the valve over time. Typical repairs include valve replacement, sensor or controller replacement, or wiring repair.
What to do? Have a fuel system clean done at DV Automotive, at least every 30,000km. This will minimise carbon build-up. Attend to any check engine lights immediately by bringing your car straight to us.
