Coil Packs

[philip600]

Hi, I just bought a second hand coil pack with genuine plug leads from a well known auction site as spares for my S4s, the leads look fairly new & are in good condition, end to end resistance readings are all good but one of the coils has a small hairline crack at the base where the mounting bolt goes through, is it likely this is knackered as I read they often crack here. I suppose that's the risk with buying second hand & I didn't pay a lot for them.

Phil.

[Vulcan Grey]

fill it with epoxy

[philip600]

Hi Travis, I've read when they crack they cause problems, is that due to water ingress through the crack or because the case is the insulation & the spark can 'track' ?

Phil

[Vulcan Grey]

possibly both. But the coils are normally coated to prevent them from having shorted turns.  Filling the coil with an epoxy, which is an insulator, will prevent both issues, assuming you can coat everything sensitive.

[dodge1979]

I wouldn't bother with it. For what new msd units cost it isnt worth having a 2nd hand one with a crack. Itll fail. It could have had a crack for years and been subject to water ingress and road salt eating away inside. Id replace both current working ones if you were concerned and keep your original ones if known to be good, or at least one if only one is good, as your spare..