What's a coil pack? As I understand, these function as distributed coils replacing the single coil found previously. My real question is, "Why do these need replacement whereas in the older model automobiles the coil is seemingly indestructable?"

Eric

 

google helps, as does wikipedia

 

Cause they get weak with time and you end up with misfIres from weak ones. A coil on plug igntion is way better than the old distributer, , coil, and wires. Hotter spark, less chance of misfires etc...

 

The answer is the placement of the coils. The Jaguar S Type has individual coils not coil packs. These coils are mounted directly to the spark plugs. This means they are mounted on the engine and very close to the combustion chamber. This also means they are exposed to a lot of heat cycles.

My prior car was a SHO it has 3 coil packs. So each coil pack feeds two cylinders. But the coil packs were mounted externally on the engine. They lasted longer. On even older cars they had one coil for eight cylinders. Some coils were even mounted on the fender or firewall to keep them from the heat and vibration of the engine. With a modern DOHC COP setup the coils are wear items just like the spark plugs.
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So do folks on this forum...I'm just sayin', why google when you can reach out to your forum buds?

If you googled "s-type coil packs" it will probably bring up a thread from here.

 

It's a balance between things which are hard to find out except on here (or similar jag forum) and things which are trivially easy to find using google etc.

Using google etc for simple things means you get a quicker answer and don't fill up the forum with things better answered via google.

 

Thanks tbird6. That's the answer I was looking for. I'd read all about this "new approach" of distrubuting the coild function but couldn't firgure out why they'd fail seemingly more often.

Interestingly enough...I'd checked wikipedia before I even asked the question.

Eric