[Calicoastin]

My 2003 540i has around 82,000 miles on the odometer and wanted to change the spark plugs but would like to read about the process involved in changing those before I get started. So my question would be what is the process? Any DIY guides anyone on this forum know about? I've replaced the lower radiator hose on this car and done other work on my previous car ('96 Impala) such as replace entire fuel system, replace intake manifold gaskets and water pump.

I'm looking for a diy with pictures to help in the process so any help is much appreciated, thanks in advance.

 

[Orxan4ik]

TU motor is the same. Nvm comments lol

 

[Calicoastin]

Thanks, I'll favorite this for quick reference.

 

[540 M-Sport]

I would recommend using the NGK four prong oem plugs. You are sort of at the borderline of doing the following, but you might consider replacing the spark plug extensions too. After 100k or so, it is worthwhile. Since the plugs are good for at least 60k, it is debatable whether to replace the extensions now, or at your next plug change.

 

[CSMBlack-540i]

I would recommend using the NGK four prong oem plugs. You are sort of at the borderline of doing the following, but you might consider replacing the spark plug extensions too. After 100k or so, it is worthwhile. Since the plugs are good for at least 60k, it is debatable whether to replace the extensions now, or at your next plug change.

"Extensions" meaning coilpacks?

 

[540 M-Sport]

No, the extension between the coil and the spark plug. The official BMW part name is "spark plug socket" which is a confusing term. I have most often heard it referred to as a spark plug extention.
BMW part number is 12139067831 I believe it is common to all the E39 coil on plug cars...I6 or V8.

They are only $5.44 each from RM European. http://www.rmeuropean.com/search.aspx?keyword=12139067831
They really get cooked in those spark plug wells after many years and thousands of miles. Eventually they will develop faults that can cause a short to the plug well, causing a misfire, and a "Service Engine Soon" light and corresponding misfire code.

 

[Orxan4ik]

No, the extension between the coil and the spark plug. The official BMW part name is "spark plug socket" which is a confusing term. I have most often heard it referred to as a spark plug extention.
BMW part number is 12139067831 I believe it is common to all the E39 coil on plug cars...I6 or V8.

They are only $5.44 each from RM European. http://www.rmeuropean.com/search.aspx?keyword=12139067831
They really get cooked in those spark plug wells after many years and thousands of miles. Eventually they will develop faults that can cause a short to the plug well, causing a misfire, and a "Service Engine Soon" light and corresponding misfire code.

damn dude, you always come up with some good info about maintenance that doesnt cost very much

 

[CSMBlack-540i]

No, the extension between the coil and the spark plug. The official BMW part name is "spark plug socket" which is a confusing term. I have most often heard it referred to as a spark plug extention.
BMW part number is 12139067831 I believe it is common to all the E39 coil on plug cars...I6 or V8.

They are only $5.44 each from RM European. http://www.rmeuropean.com/search.aspx?keyword=12139067831
They really get cooked in those spark plug wells after many years and thousands of miles. Eventually they will develop faults that can cause a short to the plug well, causing a misfire, and a "Service Engine Soon" light and corresponding misfire code.

Thanks for that! I never looked closely but always thought the ignition coil and extensions are ONE PIECE. LOL :thumbup: