1995 E34 535i Do ignition coils earth through the Cylinder Head Cover?

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  1. 1995 E34 535i Do ignition coils earth through the Cylinder Head Cover? 
    #1
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    Weisebar's Car Details
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    I'm in the process of cleaning up my engine and whilst dismantled will clean up and re-coat the Cylinder Head Cover. I'm considering powder coating for a long lasting finish but am wondering whether the ignition coils pick up an earth from their attachment points on the cover and powder coating would then insulate them from earth.
    95 e34 525i
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    #2
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    TheEnd's Car Details
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    Yes, they do to a degree, but not officially.
    The main power is fed back through the connectors to the ECU which switches the coils on and off.
    The secondary coil earths though the spark plug to make the spark, then grounds to the head.

    They are mostly self contained, but as they are high voltage, they also have a safety grounding at the bolts, and you'll see the connectors that join the coils and a small earth strap that leads to a head stud.

    They should be fine to ground between each other, and also through the top of the coil pack to the nut and bolt that holds them down.

    The extra grounding isn't needed, but helps avoid electrical noise, and also will hopefully ditch so of the 40kV that can zap the ECU if the coil starts to break down.

    I wouldn't worry about powdercoating destroying the ground, just follow the original paint on the cover, and make sure all the connecting earth straps are put back (you'll see the metal tags used as a cable tidy too)
     
     

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    #3
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    After powder coating i would run a tap thru the head anyway.. Spark plugs are the last thing you want to seize in so i wouldnt wana coat the threads in powercoat, that stuff is fairly thick lol

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    Quote Originally Posted by Daler69 View Post
    After powder coating i would run a tap thru the head anyway.. Spark plugs are the last thing you want to seize in so i wouldnt wana coat the threads in powercoat, that stuff is fairly thick lol
    The cylinder head cover would be off from the car anyhow so no powder coat will get over the plug threads.

    Only be the cylinder head cover threads to clean up with a tap afterwards.
     
     

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