Coil ageing

[Bubble Meister]

I've maintained my van pretty well over the last 12 years but I'm starting to suspect that one of the ageing components is the coil.

Can coils degrade over time and if so, why?

My understanding is that it's two coils immersed in oil. So technically the coils shouldn't corrode due to the lack of oxygen.

I like to know this type of "pooh". Knowledge and understanding are key to fault diagnosis and cost savings!

[dsmith1974]

They can degrade as I've had to replace one to get a car working again. Not sure exactly why, but assuming the coil is copper then the 12 volt planet website says this (http://www.12voltplanet.co.uk/cable-siz ... ction.html" onclick="window.open(this.href);return false;):

'[wire] is susceptible to 'work hardening' when subject to vibration and mechanical shock, such as is experienced when installed in a vehicle'.

Not sure how often you should replace a coil?

[marlinowner]

Its a tricky one, most of my kitcar wiring and electrics including dynamo(!), coil, distributor are original from 1968 Triumph GT6 - Lucas parts now in their 5th decade and still reliable. I certainly wouldn't feel the need to change any ignition parts if the engine is running well. Think the HT leads might be original as well, don't think I even changed them when I went from GT6 to TR6 engine, and that was early 1980s.