BMW E90/92 Brake Job Must Read

If you change your BMW brake pads and/or rotors, you must change both wear sensors at the same time. The BMW will trigger a brake wear warning if you only replace one sensor. I learned this the hard way.

I replaced my rear rotors and brake pads with Zimmerman Z-Coat and StopTech. For the brake sensor, I used a non-OEM brand named Bowa. Huge mistake. The Bowa sensors are one-third the price of OEM sensors for a reason. They have almost no shielding for the wire that plugs into the brake pads that rubs against your suspension causing breaks and fraying. I cannot recommend buying OEM brake sensors enough because the entire wire is protected. 

I'm certain that changing the rear brake sensor only tripped the warning light, but lets say I changed both sensors at one time. The light still would have triggered because the Bowa wires were frayed after a couple of drives. 

Please save yourself the headache and change all brake pads, rotors, and sensors at once and do a reset. It will save you the time of taking everything apart again.

Apparently the BMW computer measures the wear at both sensors at the same time. If one changes but the other is the same it triggers the brake warning light. 

How to Change Spark Plugs on a BMW E39 530i

DIY: Spark plugs on BMW E39s equipped with M54 inline six engines. May apply to M52 engines and E46s.
BMW recommends the spark plugs be changed every 100,000 miles which seems a bit high. Many drivers suggest 60,000 - 80,000 miles.

Tools:

• Various flat tip screwdrivers
• 10 mm socket
• Ratchets and extensions
• 5/8" Spark plug socket
• Torque wrench

Parts:

•  6 Spark Plugs
• NGK BKR6EQUP
• Bosch FGR7DQP

Recommended:

• Dielectric grease for coil harness connectors

Steps: 

• Open hood
• Remove passenger side cabin filter hose. 
• Optional. Will make this job much easier if removed. 
• Use a flat tip screw driver and detach three clips.

• Pull and remove hose from micro filter cabin box.
• Twist and pull hose out from opening. See picture below.

Rubber O-ring that fits over the hole came off with the hose. Not sure if that is supposed to happen but it is easy to reinstall.

Hose completely removed.

• Use a flat tip screwdriver and pop out two small circular covers. See red circles below.

• Use 10 mm socket and remove two nuts holding engine cover. Picture of 10 mm nut below.

• Remove oil fill cap.
• Remove engine cover.
• Reinstall oil fill cap to ensure nothing falls into engine.

• Use flat tip screwdriver and raise metal clips on each coil. 
• Unplug female connector to each coil 

• Use 10 mm socket and remove two 10 mm bolts holding each coil. 
• Coil #1 and #6 have wires attached to them. Note their position for reinstallation. 

#6 Coil. Note the wire on the left.

• Remove each coil by pulling them out.
• Mark each coil to which cylinder they belong to or arrange them in order so they go back to the same spot on installation.
• Use 5/8" spark plug socket and extension to remove spark plugs.
• I highly recommend AMPRO's Spark Plug Socket since it comes with a large extension. 
• GearWrench's 5/8" Spark Plug Socket works as well, but you will need an extension to reach the plugs.   
• Be careful not to use any large side motion when breaking the torque on the plugs. 

Original BMW NGK Spark Plugs removed.

• Install new spark plugs with 5/8" socket and be careful not to cross thread. 
• NGK plugs are coated with a metal jacket and do not need anti-seize.
• The Bentley manual says to torque spark plugs to 18 lb-fts.
• Various sources and NGK list the torque values around 20 - 25 lb-fts. 
• Reinstall coils 
• Install two 10 mm bolts to each coil
• Apply dielectric grease (optional) to female connector and plug into coil
• Press down on metal clips that lock connectors to each coil. 
• Reinstall cabin air filter hose (if removed) 
• Insert end into body of car and twist
• Reinstall other end to filter box and pull towards box so the three clips snap into place
• Remove oil fill cap
• Reinstall engine cover and two 10 mm bolts securing cover
• Reinstall oil fill cap
• Reattach 2 small round clips over 10 mm engine cover bolts. 

Notes: 

It is a good idea to change any coils that are bad at the same time.
Check the plugs to see if there is any fouling or wet oil and gasoline on them
If you have a valve cover gasket leak, this would be a good time to change the gasket.
Changing the old spark plugs may clear any misfires or poor fuel economy and smooth the idle.
NGK says to not use anti-seize because there is a risk of over torque and it is not needed because their threads are coated. It is up to you to decide if you believe NGK and to use or not use anti-seize.