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Q: Coils and spark plugs keep getting worn

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The spark plugs and coils keep going out on my car. I've noticed that the coil becomes very hot to touch after a while. I keep replacing them usually once in a 25 days or so. What could cause them to go out so quickly?

A: Hello there, this is a more uncommon proble...

Hello there, this is a more uncommon problem on the 2011 BMW 535i. A few different faults can cause the spark plugs and coils to fail prematurely. The most common would be contamination from a valve cover or other oil leak onto the spark plugs. Other possible causes would be a wiring fault, primary coil issues, or a poor engine ground. Any of these faults can cause high resistance to be found in the spark plug, which in turn works the spark plug and coil harder. The coils and spark plugs should last much longer than the 25 days as you noted. With this type of issue, there is something larger going on which requires diagnosis. A qualified technician, such as one from YourMechanic, will be able to diagnose what is causes the coils and plugs to fail early and be able to perform any repairs required.

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