The engine of your Skoda Octavia Tour may start to work unstable, especially at idle speeds or during acceleration. Often the cause of such failures is not the banal wear of spark plugs, but the failure of the ignition system, namely the module responsible for the supply of sparks.
If you notice missed ignition of the mixture, increased fuel consumption or the appearance of an error on the dashboard, you need to urgently conduct a diagnosis. Ignoring these symptoms can damage the catalytic converter and cause costly exhaust system repairs.
Owners of cars with motors 1.6 MPI and 1.8 TSI Often faced with the problem of failure of one of the coils. In this article, we will discuss how to identify a faulty element without visiting a service center, using available tools and attentiveness to the behavior of the car.
Main signs of a faulty ignition coil
The first signal of problems in the ignition system is a change in the engine. You can feel the vibrations that are transmitted to the steering wheel and seats, especially when stopping at traffic lights. This is due to the fact that one of the cylinders stops working effectively or misses the clock altogether.
The indicator on the dashboard may come on Check Engine. In some cases, it begins to blink, indicating serious ignition misses that can damage the catalyst. Do not ignore this signal, as unburned fuel can get into the exhaust system.
Also, pay attention to the dynamics of acceleration. The machine can twitch when pressed on the gas pedal, especially under load. The engine loses power and it becomes difficult to maintain speed on the rise. These symptoms are often confused with problems in the fuel system, but the cause may be precisely the spark.
- π¨ Indicator flashing Check Engine during acceleration
- π A sharp decrease in engine power under load
- πͺ Increased fuel consumption for no apparent reason
- π Unstable work at idle speeds with vibrations
β οΈ Warning: If the Check Engine light flashes, stop driving at full load immediately. This can cause the catalytic converter to fail, which costs significantly more than a new coil to replace.
Preparation of diagnostic tools and equipment
For a quality check, you will need the minimum set of tools that most motorists have. The main tool will be a digital multimeter that can measure resistance and voltage. Analog devices may not give accurate readings for modern ignition systems.
You will also need screwdrivers with a cross and flat sting, as the fastening of the coils on the Skoda Octavia Tour They're often fixed with screws. Donβt forget to prepare gloves and, preferably, a flashlight, as the under-hood space can be dark and cramped.
If you have access to a diagnostic scanner OBD2This will greatly simplify the task. The scanner will help you read specific error codes that indicate the cylinder number where the problem is. This will save you from having to go through all the coils in a row.
- π Digital multimeter with resistance measurement function
- π§ Set of screwdrivers and end keys for removing coils
- π» OBD2 Diagnostic Adapter (optional, but desirable)
- 𧀠Dielectric gloves and clean rags
- Multimeter
- OBD2 scanner
- There's nothing
- Both
Visual inspection and preliminary assessment
A thorough visual inspection is required before starting electrical measurements. Remove the decorative plastic engine casing if it is installed to access the ignition coils. Examine their body for cracks, breakage marks or melting.
Pay special attention to contact groups and wires. They shall be free from corrosion, oxidation or mechanical damage to the insulation. Often the problem lies not in the coil itself, but in poor contact with the connector, which causes unstable work.
Look at the state of the spark plugs under the coils. If there is black soda or traces of oil on the spark plug insulator, this may indicate problems with the seal or that the spark is piercing to the side. Clean spark plugs with normal color of soda are a good sign for further diagnosis.
- π Inspect the body for cracks and breakage marks
- β‘ Check the contact groups for oxidation.
- π§Ό Evaluate the condition of spark plugs under the coils
β οΈ Note: Do not attempt to remove the coils on the engine or immediately after switching off if the engine was hot. Plastic elements can be fragile and the risk of burns is high. Let the engine cool down.
Why can the coil have breakage marks?
At high voltage, the spark can break through the insulation, leaving characteristic black tracks or dots. This often occurs at the connection points of the housing to the insulator or around the central electrode.
Step-by-step instruction for multimeter verification
Checking the resistance of the coil is the most reliable method of detecting a malfunction. You need to remove the suspicious module and disconnect it from the connector. Switch the multimeter to resistance measurement mode (Omas) and select the appropriate range.
Measure the resistance of the primary winding. To do this, apply probes to the power contacts (usually this is the central contact and mass contact on the connector). Normal value for most coils on Skoda Octavia Tour ranges from 0.4 to 2.0 Ohm. If the value tends to infinity or is equal to zero, the coil is faulty.
Next, measure the resistance of the secondary winding. One probe is connected to the central contact, and the second to the mass (coil body or special contact). The normal range is much higher and usually ranges from 6,000 to 15,000 Ohms. A significant deviation from the norm indicates a break or interturn circuit.
βοΈ Multimeter coil check
Compare the results obtained with the data for a working coil. If you have the opportunity, measure the parameters of the neighboring coils. A significant difference in performance between identical details will indicate a problem node. Remember that temperature also affects resistance, so only compare under the same conditions.
- π Measure the primary resistance: it should be
0.4 - 2.0 Ohm - π Measure secondary resistance: should be
6 - 15 kom - βοΈ Compare the indicators with serviceable neighboring coils
- π« If the resistance is infinite or zero, the replacement part
For more accurate measurement, press the multimeter probes tightly against the contacts, but do not allow them to touch each other. Any accidental closure of the probes will distort the result of measuring the resistance of the coil.
Comparative table of coil parameters
For clarity, we give a table with typical resistance values for ignition coils installed on the model. Octavia Tour with engines 1.6 and 1.8. Remember that these values may vary slightly depending on the manufacturer (Bosch, VAG, Delphi) and the year of the carβs production.
| Coil type | Primary winding (OM) | Secondary winding (kohm) | Manufacturer |
|---|---|---|---|
| Original VAG | 0.5 - 1.0 | 6.0 - 12.0 | Volkswagen Group |
| Analogue Bosch | 0.4 - 1.2 | 5.5 - 13.0 | Bosch |
| Analogue Delphi | 0.6 - 1.5 | 7.0 - 14.0 | Delphi |
| Faulty (cliff) | β (infinity) | β (infinity) | Any |
| Faulty (CZ) | 0.0 | 0.0 | Any |
Use this table as a guide. If your measurements go far beyond these limits, the probability of malfunction is extremely high. However, if the values are at the border of normal, but the engine is unstable, it is recommended to conduct additional check under load.
Resistance of the secondary winding is the most critical parameter. It is here that interturn circuits most often occur, which are difficult to identify during visual inspection, but they destroy the spark under load.
Replacement method (Swap test)
If you do not have a multimeter or want to confirm the diagnosis visually, use the placement method. This is the easiest and fastest way to determine which coil is to blame for the ignition misses. For this, you will need a diagnostic scanner or the ability to reset errors.
First, count an error indicating a gap in a particular cylinder (e.g., P0301 for the 1st cylinder). Then remove the coil from this cylinder and set on a neighboring, for example, on the 2nd cylinder. Clear the errors and conduct a trial trip.
If the error shifted to a new cylinder (e.g., now the P0302 is on fire), then the problem is precisely in the coil. If the error remained on the first cylinder, then the problem is in the spark plug, wiring or the engine itself, and the coil is serviceable.
- π Remove the coil from the problem cylinder
- π Install it on a knowingly serviceable cylinder.
- π Take a ride and check if the error has shifted.
- β If the error is passed, the coil is faulty.
β οΈ Note: When replacing the coils in places, be sure to clean the connectors and make sure there is no moisture. The moisture in the connector can mimic the coil malfunction, creating false conclusions when testing.
What to do if the error has not shifted?
If the error remained on the same cylinder after replacing the coil, check the spark plug. Often the problem lies in it, although it may look normal. Also check the integrity of the wiring to the coil.
Recommendations for the selection and installation of a new coil
After confirmation of the fault, you need to choose a quality replacement. The market is present as original details. VAGand quality analogues from proven brands. Cheap Chinese counterfeits often can not withstand several thousand kilometers of mileage, creating risks for the electronic control unit.
When installing a new coil, be sure to clean the landing place from dirt and dust. Use dielectric lubrication on the contacts to prevent oxidation and ensure reliable contact. This will extend the life of both the new coil and spark plugs.
Tighten the fastening bolts with moderate effort. The plastic coil body is quite fragile and can crack when retracted. After installation, make sure the connector snaps before the characteristic click, and check for no backlash.
- π Choose trusted brands: Bosch, NGK, VAG
- 𧽠Clean the seat before installation
- π‘ Use dielectric lubrication on contacts
- π§ Do not pull the bolts of the mount so that the body does not crack.
The use of an original or certified replacement is critical to the durability of the ignition system. Savings on the coil can lead to failure of expensive ECU engine or coil of other cylinders due to voltage surges.
Frequently asked questions and answers (FAQ)
Is it possible to drive with a faulty ignition coil?
Technically possible, but not recommended. Riding with a ignition skip leads to unburned fuel entering the catalyst, which can melt it. In addition, the vibrations of the engine destroy the pillows and other nodes.
How much does it cost to replace the coil with STO?
The cost of the work is usually 1500-3000 rubles per coil, depending on the region and the difficulty of access. Nana Octavia Tour Access to the coils is relatively simple, so the price will be closer to the lower limit.
Do you change all the coils at once or just one?
If one is out of order, the others are likely already worn out. If the budget allows, it is better to replace everything at once, especially if the mileage exceeds 100,000 km. This will save time for re-disassembly in the future.
Will cleaning contacts from oxidation help?
Yes, if the problem was in poor contact, not in the coil winding. Cleaning and treating contacts with dielectric lubricant can restore work if the coil is working but oxidized.
How often should I check the ignition system?
It is recommended to conduct a visual inspection and check of spark plugs at each planned maintenance. If the engine has started to work unstable, the check should be carried out immediately, without waiting for scheduled maintenance.
When purchasing new reels, be sure to check the packaging for integrity and the presence of manufacturer holograms. Counterfeit parts are often not properly labeled and packaged, which is the first sign of a defect.