Disclaimer: These articles and procedures are examples of how and what can be done. These all assume the use of proper tools and the M535i SIG and I take no reponsiblity for any incorrect information posted on this page. If you are not comfortable in undertaking any automotive repair, take your car to a qualified BMW mechanic. Otherwise use this information at your own risk. Like the copyright says any duplication of this information with out the explicit permission of the M535i Special Interest Group & Registry is prohibited. If you run into any specific problems please email me through the link at the bottom of the page and I will try to assist you as best I can.

1. Disconnect harness connector from coil. Connect multimeter between terminal 15 (+) in connector and ground. (Terminal 15 is the farthest right when the connector has the two tabs on the top)

2. Turn on ignition and check for battery voltage. If not present, check wire between terminal 15 and ignition switch.

(Caution: wiring to terminal 15 is not fuse protected, use care when testing circuit)

Use a multimeter to test coil primary resistance at coil terminals: 1(-) and 15(+) - 0.4 - 0.8 ohms. Terminal 1 is the farthest on the left of you look at the harness connector, thus the farthest left on the coil itself. The best way is to inspect the coil and coil housing for hairline cracks or leaking casting material. A leaky ignition coil may indicate a faulty engine control module. Check ECM before installing new coil. Also, common sense: Try removing the plugs and inspecting for difference between them. A poor firing plug may be wet with fuel and/or black and sooty, but not always. If a coil is not operating, the engine management system will electrically disable the fuel injector to that cylinder. The key is to look for differences between cylinders.

A clunking in the front suspension, can be a couple of things. First I would think that it would be the upper strut bearings. The way to check this is to find a bump on a secluded road and have a friend drive the car very slowly over the bump with the hood open and your hand on the upper strut bearing. If you feel the clunk in your hand then it is most likely either the upper strut bearing or the shock. The next thing to look at is whether the bearing is deforming or the strut is moving and the bearing is not. If the rubber of the bearing is deforming then you have a seized strut. If the strut moves and the bearing does not deform then I would suggest replacing the bearing. The clunking can also be caused by very badly worn ball joints, but I doubt that if you have no shimmy problems.