Magnecor receives many used ignition wires
sent in for evaluation from both the auto industry and consumers.
We receive original equipment and aftermarket wires, and also our
own wires that have allegedly "failed" for various
reasons. Some vehicles will prematurely destroy any brand
ignition wires unless proper preventive maintenance is performed
regularly to prevent engine and other problems causing damage to
the ignition wires. As those vehicles age, virtually everything
in the engine bay is affected by corrosion and oil leaks, and
problems that cause damage to ignition wires will occur more
often, and for this reason, even more preventive maintenance will
be required. We have prepared technical bulletins to alert
consumers of the vehicles most prone to problems that cause
ignition wire failure, as well as other useful information (which
is worth reading, even if you don't own any of the vehicles in
Often, we receive wires that have been declared "bad" or "faulty" by automotive technicians and consumers that have obviously failed for reasons beyond the control of an ignition wire manufacturer. On many vehicles, ignition wires are located where excessive heat (usually on modified engines with poorly designed headers), vibration, leaking oil and water retention in deep un-drained spark plug holes can cause all sorts of problems for ignition wires if the engine is not serviced properly and regularly. Also, it never ceases to amaze us how many wires not fitted correctly are declared "faulty". Of course, as long as vehicle manufacturers design engines where it's impossible to easily reach (or even see) the spark plugs, there will always be times when spark plug wires are not fitted properly.
In recent years, vehicle manufacturers using "multi-valve" engines with spark plugs located in deep un-drained holes in the cylinder head have gone out of their way to create spark plug wires using complicated extended connectors on the spark plug end which have little or no hope of surviving arcing caused by water and oil in the spark plug holes without constant vigilance on the part of the vehicle owner. With some vehicles, it can cost an owner hundreds of dollars in labor to remove and replace components (such as intake manifolds) just to get to the spark plug holes. For this reason, it's understandable some vehicle owners won't be as vigilant as others, particularly as there's never a warning from vehicle manufacturers as to problems caused by poor design.
Another developing problem is premature spark plug failure. Modern engines use small size spark plugs, and engines boosted with turbocharging and supercharging place additional strain on these small spark plugs, particularly when gaps are enlarged by erosion or adjustment. Both vehicle and spark plug manufacturers would like you to think spark plugs last from 30,000 to 100,000 miles, and mostly they do. Unfortunately, a surprising number don't, and premature failure is usually caused by either the porcelain insulator cracking or developing leaks around the seals. Inevitably, the spark plug wires are initially blamed for the resulting engine miss-fire, or combustion gases leaking inside the wire spark plug connectors which pops them off the spark plugs, or the galvanic binding of terminals onto spark plug tops (dissimilar metals) caused by corrosive combustion gas leaking past the top of the spark plug porcelain seal.