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Replace a Spare part Ignition coil – a defective one or if the limit of use has been already reached. Find out useful information about Ignition coil
Faulty ignition coil
mechanical damage of the ignition coil;
wear and tear of the part;
overheating of the ignition coil;
wear of the ignition coil terminal;
rupture of the coil winding.
Symptoms of the ignition coil failure
dips in the engine cycle;
decrease in maximum power of the vehicle;
the engine failures occur more frequently with a high humidity level in the atmosphere;
increase in fuel consumption;
indicator reading «Check Engine» on the dashboard.
Causes of a faulty ignition coil
use of low-quality spark plugs;
engine overheating;
exposure to high temperatures, dust and dirt;
damage to the coil insulation at a voltage higher than 35 000 V;
vibration of coils and looseness of fastenings;
overload of electrical circuit.
Diagnostics
Identifying the faulty ignition coil without special equipment is impossible. Independently you can estimate the appearance of the coil: if the housing has traces of oxidation, small holes or black spots, the coil is out of order.
If there is a slightest sign of failure, check the item at a service station. Use an ohmmeter or multimeter to measure the resistance of the primary and secondary coil windings. The primary winding resistance should be in the range of 0.5-2 ohm. Value of secondary winding resistance should be in the range of 6000-15 000 ohms. To accurately determine the fault it is necessary to find out the exact values of the norms in the vehicle technical documentation.
The service life of the ignition coil is 60 000-80 000 kilometers. Diagnostics of the system is recommended after 30,000 kilometers or every six months.
Repair and replacement of ignition coils
The ignition coil cannot be repaired. Ingress of oxygen into the body always impairs the system, so even small deviations in the part’s performance require only to replace it.
One of the main factors of the part normal operation is correct wiring. Replacing the coil does not take much time, but if you do not have the necessary knowledge, you should refer to a service shop.
black smoke and a strong petrol smell coming from the exhaust pipe;
increased fuel consumption;
difficult engine start and unstable running;
vibration at idle or the engine stalls;
engine power loss;
the “Check Engine” dashboard warning light is on.
How can I test the ignition coil myself?
For this work you will need rubber gloves, pliers, a set of drive sockets and ring spanners, and an ohmmeter or multimeter. All tools should have insulated handles.
Instructions for checking the component:
Visual inspection: there should be no mechanical damage to the part, such as black spots or white cracks. The smell of burning also indicates that there is a problem.
Measuring the resistance. Turn off the engine and let it cool down before testing. Then:
Disconnect the wires.
Unscrew the fasteners.
Remove the component.
Measure the resistance of the primary and secondary windings. To do this, connect the multimeter probes to the contacts on the component.
Compare the readings with those specified in your vehicle owner’s manual. Usually, the resistance should be 0.7–1.7 ohms on the primary winding and 7.5–10.5 kiloohms on the secondary.
How is the new ignition coil installed?
Precise instructions can be found in your vehicle’s technical documentation. A general outline of the procedure would be as follows:
Turn off the engine and let it cool down.
Disconnect the negative battery terminal.
Mark the wires and disconnect them from the faulty part.
Unscrew the fasteners and remove the broken part.
Clean dirt and residue from the mounting seat.
Use an electric contact cleaner to clean the ignition coil connector.
Install the new component and tighten the fasteners.
Connect the wires to the ignition coil observing the correct polarity.
Connect the negative battery terminal.
Run the engine in order to make sure that the component works properly.
