Spark plugs — removal, installation and adjustment (VW Sharan 1)

The spark plugs have a thread diameter of 14 mm. The manufacturer recommends specific spark plugs, but spark plugs from other manufacturers with the appropriate combustion heat can also be used.

The distance between the spark plug electrodes is shown in the adjustment and control table.

Before removing the spark plugs, clean the wells in which the spark plugs are located so that dirt does not get into the holes for them after removing the spark plugs. To remove the spark plugs, use only a specially designed key, and the high voltage wires from the spark plugs on the VR6 engine can only be removed with a special tool.

When working with spark plugs, observe the following rules:

• when removing the high voltage wire from the spark plug, do not pull on the wire itself, but only on the tip of the high voltage wire;
• after removing the spark plugs, arrange them in the order of the cylinders;
• if, when removing, a spark plug is stuck, do not use force, as you can strip the threads in the cylinder head made of light alloy. In this case, as an exception, try to remove the spark plug by warming the engine to operating temperature, observing safety precautions;
• wait until the engine has cooled down before installing new spark plugs. Otherwise, the threads will be too tight (due to thermal expansion of the cylinder head material);
• spark plugs should be tightened to 30 Nm (2.0-liter engine) or 25 Nm (vR6 engine);
• if you don't have a torque wrench, tighten the new spark plug lightly with a spark plug wrench so that the sealing ring fits into place, then tighten it another 90° with a spark plug wrench. If you're installing old spark plugs, tighten them another 15° or so.

In the company's maintenance schedules "Volkswagen" it is recommended that spark plugs be replaced every 60,000 km or every 3 years. Even if the spark plugs are working without problems, they should still be replaced at the recommended intervals.

Adjusting the gap between the spark plug electrodes

Before installing the spark plug, check and adjust the gap between the central and side electrodes (Fig. 224).

This operation must be carried out before winter operation of the car. The gap between the spark plug electrodes must be within 0.7-0.9 mm.

During operation, this gap constantly increases due to natural wear of the contact material. An increase in the gap leads to an increase in breakdown voltage, which causes a disruption in spark formation and increased fuel consumption.

The gaps between the electrodes should be checked using a round feeler gauge. A flat feeler gauge does not take into account the unevenness of the electrode wear and can give a large error in measuring the gap.



The gap between the electrodes can be increased or decreased only by bending the side electrode using a special tool (Fig. 225). To do this, place the hook of the tool on the side electrode and carefully bend or straighten it.