How to check spark plug gap
Content
If checking the gap of the spark plugs showed that the value does not correspond to the norm, it is necessary to carefully clean the surface of the part with a rag, examine it for damage: during operation, chips and cracks may appear on the insulator. Directly adjusting the distance consists in bending or bending the side electrodes. To do this, you can use a flat-tip screwdriver or pliers.
Timely check of the gap of the spark plugs is a prerequisite for the stable operation of the engine and the safe operation of the car. The procedure is performed independently or in a car service, but in any case, regularity is important.
Features of checking at home
The gap between the electrodes is set at the factory, but during the operation of the car, the distance may change. As a result, the engine begins to function intermittently (triple, loss of power), parts will fail faster, and fuel consumption may increase. Therefore, the ability to independently check the actual distance between the electrodes and set the right one is important for the car owner.
First you need to remove the part from the engine and remove the carbon deposits that have accumulated on the surface. So a probe of the right size is placed between the electrodes. The norm is the position when the tool passes tightly between the contacts. In other cases, adjustment is necessary. The exception is situations when too many combustion products of the fuel mixture have formed on the surface and the part needs to be replaced with a new one.
Clearance table
The results of the non-motorized tests of spark plugs, during which the auto repair masters checked the manufacturer's compliance with the established parameters, are summarized in the table.
| Spark gap | |||
| Name | Declared by the manufacturer, mm | Average, mm | Product spread, % |
| ACDelco CR42XLSX | 1,1 | 1,14 | 8,8 |
| Berry Ultra 14R-7DU | 0,8 | 0,85 | 0 |
| Brisk LR1SYC-1 | 1,1 | 1,09 | 4,9 |
| Valeo R76H11 | - | 1,1 | 9,1 |
| ween370 | 1,1 | 1,1 | 5,5 |
| "Peresvet-2" A17 DVRM | - | 1,05 | 9,5 |
Within the limits of the permissible deviation of the distance between the contacts, all manufacturers represented are included. This allows you to ensure that after installing a new part, the motor will work without failures.
Checking the spark plugs
How to measure the gap between the electrodes
It is necessary to check the correspondence of the distance between the central and side contacts to the norm using a special probe. This device is of the following types:
- Coin-like. The gauge is a bezel located along the edge. The device is placed between the electrodes, you need to change the position of the "coin" until it fits snugly against the contacts.
- Flat. A set of probes, structurally reminiscent of multitool tools.
- Coin-wire. Check the distance by inserting wires of fixed thickness between the electrodes.
For measurements, the part is removed from the engine, having previously disconnected the armored wires. After cleaning, the probe is placed between the contacts, evaluating the result.
How to change
If checking the gap of the spark plugs showed that the value does not correspond to the norm, it is necessary to carefully clean the surface of the part with a rag, examine it for damage: during operation, chips and cracks may appear on the insulator. Directly adjusting the distance consists in bending or bending the side electrodes. To do this, you can use a flat-tip screwdriver or pliers.
The part is made of durable metal, but this does not guarantee the absence of creases at elevated pressure. You can change the distance no more than 0,5 mm at a time. After each of these approaches, you should check the result with a probe.
Repair Technicians recommend:
- do not overtighten the spark plugs: the internal thread can be easily stripped;
- when adjusting, maintain equal intercontact distances;
- do not save on the purchase of parts, change in a timely manner to prevent the occurrence of more complex malfunctions;
- pay attention to the color of the electrodes, if it is different - this is a reason for diagnosing the motor.
The correct distance for a particular engine is found out by studying the operating instructions.
What causes incorrect spark plug gaps?
The result may not be correct, which will adversely affect the performance of the machine.
Increased clearance
The main danger is a breakdown of the coil or candle insulator. Also, the spark may disappear, and the engine cylinder will stop working, the system will trip. Signs of a problem that indicate the need to check the gap are misfiring, strong vibration, pops when ejecting combustion products.
Due to natural wear, the distance increases when the metal burns. Therefore, it is recommended to check single-electrode candles after 10 km of run. Multi-electrode modifications should be diagnosed less frequently - verification is necessary upon reaching 000 km.
Reduced clearance
The deviation of the distance between the electrodes to a smaller side leads to the fact that the discharge between the contacts becomes more powerful, but shorter in time. Normal ignition of the fuel in the cylinders does not occur. When the motor is running at high speeds, an electric arc can form. As a result, the circuit of the coil and engine malfunctions.
Do I need to adjust the gap on new spark plugs?
Manufacturers must strictly adhere to the distance between the contacts specified in the documentation. However, not all brands meet the quality requirements. It is also not uncommon after checking a new part that the side electrode is not positioned correctly.
Therefore, it would be useful to verify the accuracy in advance. You can check the indicator before installation, the operation will not take much time. It is easy to measure the interelectrode distance on your own, if necessary, change its value. But you can always contact a car service. They will conduct a comprehensive engine diagnostics, check the gap of the spark plug, eliminate the identified breakdowns, set the correct distance between the electrodes.
