Where is my coil?

ANSWER : Go to fuse 21 in the engine compartment to see if power goes away when you test it while the compressor is connected. If the power stays above 12.5 volts, check connections to the A/C clutch relay in the power distribution center next to the battery. If the connections are good then replace the relay and retest the components. The connection should not be loose and may show signs of heat or arching on the relay and connector. If you need some help with this issue, consider YourMechanic, as a certified technician can diagnose the cause of this electrical issue and fix it accordingly.

ANSWER : There is some sort of short in your ignition circuit on the number three cylinder. I would recommend further inspecting the wiring that controls the number three coil. It is likely that more wiring damage exists that may have been looked over. Once the short is found you should be able to resolve the issue by insulating the wires separately and preventing them from coming in contact with each other any more. If you are in doubt about this repair, consider YourMechanic for a check engine light is on inspection to determine why the fuse keeps blowing.

ANSWER : The valve cover on that side of the engine has the broken bolt boss. The only way to secure the coil is to either replace the valve cover so you have the bolt boss to bolt down the coil, or to change the coil involved in the misfire.

ANSWER : Hello,
Yes, you will need to replace coil #3. Coils are made of a series of coil windings that are designed to conduct electricity and when wet this cannot happen. I would recommend replacing the ignition coil to ensure that the coil fires properly.

ANSWER : Hi and thanks for contacting YourMechanic. Ignition coils for your vehicle are designed to supply voltage to the spark plug. To check if the coil is working, simply unplug the coil when the engine is running. If the engine stumbles, then the coil was working. If there was no change with the coil, then the coil was not working. Before determining if the coil has failed, check the spark plug for any burnt spots. This indicates that the coil is producing too much voltage. This can be caused by the spark plug fouling out, excessive oil or fuel in the cylinder, or the wires to the coil pack have no power. The symptoms of a coil pack failing is the engine having a hard start and the engine having a shake to it with a loss of power. Most of the time, if the coil fails, the computer will sense this and throw an engine light with a code p0351 for primary circuit A and / or p2305 for secondary circuit B. If you need further assistance troubleshooting your ignition system, then seek out a technician, such as one from Your Mechanic, that can assist you with your vehicle.

ANSWER : I would suggest going online and getting a wiring diagram for your vehicle. Most of the time, the coil wires will trace back to the control module. You can do a continuity, or resistance, test to figure out where the wire is broken, or what is causing the problem. I would suggest putting one probe on the connector and just start tracing the wire back until you find the break/short. Keep in mind, that if the wiring checks out, it is possible that there could be a problem with the control module itself. If this is something that you feel you could use a hand with diagnosing/repairing, contact a certified mechanic, like the mobile mechanics available at YourMechanic.com.

ANSWER : Hello. The numbers you have provided did not yield any results through my search. If the part numbers are different, and the ends are physically different, then they may very well be different coils or it may just be an updated design. I would verify with a parts specialist or BMW dealership if the parts are compatible or not. Also, keep in mind that it may be possible that the coil packs are not the source of the issue. If the Check Engine Light is on I would scan the trouble codes as they may help shed some light on if the coils are the issue or not. A certified professional from YourMechanic can come to your car’s location to diagnose the Check Engine Light and loss of power in order to make the correct repairs.

ANSWER : The two Diagnostic Trouble Codes, P0304 and P0302, refer to cylinder misfiring. A faulty ignition coil, spark plug, wire, and so forth can cause a cylinder to misfire but there are other possible causes, too. Consequently, the only way to determine the actual cause or faulty part is to perform an engine diagnostic during which each relevant part and system is tested.

If an obvious and common cause, such as a bad coil, is not immediately found during the diagnostic, these additional possible causes of engine misfiring would have to be evaluated: oxygen sensor(s), fuel injector, burned exhaust valve, catalytic converter(s), poor compression, clogged EGR valves or tubes, wrong ignition timing, vacuum leaks, low fuel or low fuel pressure, leaking head gasket, bad camshaft or crankshaft sensor, bad mass air flow or throttle position sensor, and defective computer (least likely cause).

I recommend having a certified mechanic, such as one from YourMechanic, come to your location to determine why the car is misfiring and suggest the necessary repairs.