Be sure the coils are seated properly. I found one on my E38 that wasn't snug. Usually they pop on with plenty of evidence, but its possible.

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740iLDUKE
01' DINAN 7 S62 Swap - Stratus Grau
(1587 produced in SG 440)
02' 4.6is DINAN X5 S2 Supercharged
833/3258 produced | 1/27 Dinan X5's