Recommended replacement interval for the part category Spark plug : 18 month / 30000 km

Important!

This replacement procedure can be used for:
BMW 8 (E31) 850 CSi, BMW 8 (E31) 840 i, BMW 8 (E31) 840 Ci … View more

The steps may slightly vary depending on the car design.

This video shows the replacement procedure of a similar car part on another vehicle

All the parts you need to replace – Spark Plug for 8 (E31) and other BMW models

Spark plug

        Spark plug for BMW 8 (E31) 850 CSi Petrol (380 hp)
      
        Spark plug for BMW 8 (E31) 840 i Petrol (286 hp)
      
        Spark plug for BMW 8 (E31) 840 Ci Petrol (286 hp)

Replacement: spark plugs – BMW 8 (E31). Tools you might need:

                        Electronic spray
                      
                        High-temperature anti-seize lubricant
                      
                        Torque wrench
                      
                        Drive socket # 10
                      
                        Spark plug socket # 16
                      
                        Ratchet wrench
                      
                        Flat screwdriver
                      
                        Crow bar
                      
                        Fender cover

Buy tools

Replacement: spark plugs – BMW 8 (E31). AUTODOC experts recommend:

The replacement procedure is the same for all spark plugs.
Please note: all work on the car – BMW 8 (E31) – should be done with the engine switched off.

Carry out replacement in the following order:

Step 1

Open the hood.

Step 2

Use a fender protection cover to prevent damaging paintwork and plastic parts of the car.

Step 3

Unscrew the engine cover fastener. Use a drive socket #10. Use a ratchet wrench.
Step 4

Remove the engine cover.

AUTODOC recommends:
Replacement: spark plugs – BMW 8 (E31). To avoid damaging the part when removing it, do not use excessive force.
Step 5

Unscrew the engine cover fastener. Use a drive socket #10. Use a ratchet wrench. Use a flat screwdriver.
Step 6

Unscrew the oil filler plug.

Step 7

Remove the oil filler cap.
Step 8

Remove the engine cover.

AUTODOC recommends:
Replacement: spark plugs – BMW 8 (E31). Do not use excessive force when removing the part as this may damage it.
Step 9

Install the oil filler cap.

Step 10

Tighten the oil filler cap.
Step 11

Unplug the connectors from the ignition coils. Use a crowbar.
Step 12

Unscrew the fasteners of the ignition coils. Use a drive socket #10. Use a ratchet wrench.
Step 13

Take out the ignition coils from the spark plug wells.

Replacement: spark plugs – BMW 8 (E31). Tip from AUTODOC experts:
Remember the sequence of steps for ignition coil demounting.
Step 14

Clean dirt, dust and debris from inside the spark plug wells.
Step 15

Unscrew the spark plugs. Use the spark plug socket #16. Use a ratchet wrench.
Step 16

Take out the spark plugs.
Step 17

Apply a thin layer of a special high temperature anti-seize lubricant to the threads of the new spark plugs.
Step 18

Install the new spark plugs into their mounting seats. Use the spark plug socket #16.
Step 19

Screw new spark plugs and tighten them. Use the spark plug socket #16. Use a torque wrench. Tighten it to 24 nm torque.

Replacement: spark plugs – BMW 8 (E31). AUTODOC recommends:
Don't tighten the plugs with excessive force. Exceeding tightening torque can damage the thread connection. Be careful when working with a spark plug wrench. Its skewing can cause damage to the threaded connection.
Step 20

Install the ignition coils to the spark plug wells. Make sure you hear a click indicating that it is locked in place.

Replacement: spark plugs – BMW 8 (E31). AUTODOC experts recommend:
Follow the installation sequence.
Step 21

Tighten the ignition coil fasteners. Use a drive socket #10. Use a torque wrench. Tighten it to 7 nm torque.
Step 22

Treat the ignition coil connector with electronic spray.
Step 23

Plug in the connectors of the ignition coils.
Step 24

Unscrew the oil filler plug.
Step 25

Remove the oil filler cap.

Step 26

Install the engine cover and secure it.

AUTODOC recommends:
Make sure the engine cover is properly seated. It should not be displaced with respect to the guiding fasteners.Replacement: spark plugs – BMW 8 (E31). To avoid damaging the part during installation, do not use excessive force.
Step 27

Install the oil filler cap.

Step 28

Tighten the oil filler cap.
Step 29

Screw in the engine cover fasteners. Use a drive socket #10. Use a ratchet wrench.
Step 30

Install the engine cover and secure it.

Replacement: spark plugs – BMW 8 (E31). AUTODOC experts recommend:
Make sure the engine cover is properly seated. It should not be displaced with respect to the guiding fasteners.When installing, do not use excessive force to avoid damage to the part.
Step 31

Screw in the engine cover fasteners. Use a drive socket #10. Use a ratchet wrench.

Step 32

Run the engine for a few minutes. This is necessary in order to make sure that the component operates properly.

Step 33

Shut off the engine.

Step 34

Remove the fender protection cover.

Step 35

Close the hood.

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