Parts Catalog Accessories Catalog Tech Info Tech Forums
 
Follow Pelican Parts on Facebook Follow Pelican Parts on Twitter Follow Pelican Parts on Instagram Follow Pelican Parts on YouTube Follow Pelican Parts on Pinterest Follow Pelican Parts on Tumblr
  Search our site:    
View Recent Cars  |   Cart  | Project List | Order Status | Help    
 >  >
Spark Plug and Ignition Coil Replacement
 
Bookmark and Share

Pelican Technical Article:

Spark Plug and Ignition Coil Replacement

Nick Czerula

Time:

2 hours2 hrs

Tab:

$150

Talent:

***

Tools:

Set of sockets (10mm, 5/8 spark plug socket), flathead screwdriver

Applicable Models:

BMW E46 M3 Coupe/Conv (2003-06)
BMW Z4 Convertible (2003-06)
BMW Z4 Coupe (2006)

Parts Required:

Spark plugs, ignitions coils

Hot Tip:

Work with a cool engine

Performance Gain:

Engine runs well

Complementary Modification:

Replace air filter

The Siemens digital motor electronics (DME) engine management systems in BMW 6-cylinder engines control fuel supply, fuel injection, ignition and emissions. In these systems, also known as Motronic, an electronic microprocessor, the engine control module or ECM, processes a variety of sensor inputs to monitor engine and vehicle conditions. The ECM operates the engine in accordance with driver input. It has self-diagnostic capabilities in accordance with US-mandated on-board diagnostics (OBD-II) standards and stores fault codes known as diagnostic trouble codes or DTCs, which can be accessed for troubleshooting purposes.

In the Motronic system idle speed, idle mixture and ignition timing are not adjustable. OBD-II standards require the engine to operate within extremely tight tolerances maintained by feedback loops in the electronics. These standards as well as upgraded manufacturing materials and techniques allow many automotive components to function well past times and mileages that were considered normal in previous decades. As examples, engine oil and spark plugs are capable of extended life compared to the past.

Replacing the spark plugs on your Z4 is part of routine maintenance. BMW recommends replacing the spark plugs on Z4 standard 6-cylinder models every 100,000 miles and on Z4M models with S54 engines every 60,000 miles. As mentioned above, with all the major engine and engine management design changes over the years, spark plugs now last up to three times as long as they did in years past. This is good and bad. It means you save money and time not having to service them so frequently, but run the risk of a spark plug seizing in the cylinder head. I suggest replacing your spark plugs every three years regardless of mileage. If the last time they were serviced is unknown, replace them right away.

Keep in mind that when your car was serviced before, parts may have been replaced with different size fasteners used in the replacement. The sizes of the nuts and bolts we give may be different from what you have, so be prepared with different size sockets and wrenches.

Protect your eyes, hands and body from fluids, dust and debris while working on your vehicle. If you're working with the electrical system, disconnect the battery before beginning. Always catch fluids in appropriate containers and properly dispose of any fluid waste. Recycle parts, packaging and fluids when possible. Never work on your vehicle if you feel the task is beyond your ability.

Our vehicle may vary slightly from yours as models do change and evolve, as they grow older. If something seems different, let us know and share your info to help other users. Do you have questions or want to add to the article? Leave a comment below. When leaving a comment, please leave your vehicle information.

BMW Z4 models equipped with a 6-cylinder engine utilize an individual ignition coil for each spark plug, referred to as coil over plug (red arrows).
Figure 1

BMW Z4 models equipped with a 6-cylinder engine utilize an individual ignition coil for each spark plug, referred to as coil over plug (red arrows). When servicing your spark plugs be sure the engine is cool and leave yourself about an hour to do the job. Be careful not to drop a spark plug. If you do, replace it. The spark plug insulator can crack and can lead to an engine misfire. Remove the engine cover on the cylinder head. This tech article shows Z4 models with an S54 6-cylinder engine.

Start by removing the crankcase breather hose.
Figure 2

Start by removing the crankcase breather hose. Disconnect the electrical connector (inset) by pressing the wire release and pulling the connector straight off. Then lift the solenoid (green arrow) up and out of the mounting bracket. Next, detach the breather hoses from the intake and breather (red arrows).

To remove the breather hoses, squeeze the collar and pull it straight up.
Figure 3

To remove the breather hoses, squeeze the collar and pull it straight up.

Place the breather hose and solenoid aside (green arrow).
Figure 4

Place the breather hose and solenoid aside (green arrow). You can leave the rubber hose attached. It only has to be moved enough to make room for the engine cover to come out.

Remove the six 10mm engine cover fasteners (red arrows).
Figure 5

Remove the six 10mm engine cover fasteners (red arrows). Then remove the oil filler cap (green arrow).

Lift and remove the engine cover.
Figure 6

Lift and remove the engine cover.

Unlock the ignition coil electrical connectors (red arrows) by pulling the tab up 90° and slide the electrical connector out of the ignition coil (inset).
Figure 7

Unlock the ignition coil electrical connectors (red arrows) by pulling the tab up 90 degrees and slide the electrical connector out of the ignition coil (inset).

Remove the ignition coil from the cylinder head by pulling it straight up (red arrow).
Figure 8

Remove the ignition coil from the cylinder head by pulling it straight up (red arrow). If the coil resists, twist it when pulling up to break it free from the spark plug. The ignition coil rubber boot can become stuck to the spark plug over time. You can also use a flathead screwdriver to lever the coil up and out of the cylinder head. Be very careful using this method, as the coil is made of plastic and easily damaged If you find that engine oil has contaminated the ignition coil boot, you will have to repair the oil leak and replace the ignition coil. The source of the oil leak will likely be the valve cover gasket.

I like to use a 5/8-inch thin-wall long spark plug socket (red arrow).
Figure 9

I like to use a 5/8-inch thin-wall long spark plug socket (red arrow). If the socket gets stuck on the spark plug, it can be easily removed from the top.

Using a 5/8-inch thin-wall spark plug socket on a 12-inch extension, remove the spark plug from the cylinder head.
Figure 10

Using a 5/8-inch thin-wall spark plug socket on a 12-inch extension, remove the spark plug from the cylinder head. Lightly lubricate the new spark plugs with copper based anti-seize. Thread the spark plugs into the cylinder head by hand. This will prevent accidental crossthreading. Torque the spark plugs. Reinstall the ignition coils and reconnect the electrical connectors. Be sure to route the wiring harness as it was before and connect the ignition coil grounds. Install the engine cover and check your work.

Bookmark and Share

  Search our site:    

View Cart & CheckOut | Project List | Order Status |  Help    

 

[Home] [Customer Service] [Shopping Cart] [Privacy Statement]
 [Contact Us] [About Us] [Shipping] [Map to our Location] [Careers]

Copyright © Pelican Parts Inc.

Page last updated: Fri 12/9/2016 02:55:00 AM