So I've spent a good amount of time bashing on aftermarket plug wires and coils. Basing my arguments on the fact that a spark is a spark and as long as you are making one you are g2g.

Well I should have knocked on wood because I have been chasing a misfire/studder gremline for the past 2 months and it turned out I got owned by my oem plug wires. Here's the story:

I got my car tuned by Jan at RMW during the ATL dyno session. A week or two after the tune the car started to show signs of a studder from 2800-3200 rpm. At first it was just a few pops, and eventually it got worse and worse until it sounded like a formula 1 car bouncing off the traction control. Culminating in a Cyl 1 misfire code.

I was convinced it was the tune. I called jan about umm.... 10000000 times. He took all of my calls and kept giving me a list of thing to check. (Talk about customer service) Was more then patient with me and every time I suggested it might be the tune he was like... well we've got that on a ton of cars and that issue hasn't come up. Keep looking. Check this and this... you get the picture.

What really threw me off was that if I would reset the ecu, (unplug the battery and the ecu for about 2-4 hours) the problem would go away for about 2 days, and then come back with a vengeance.

At that point I was convinced it was the tune. So I took it in to the greenville SC dealership (Century Mini) which turns out is an amazing dealership. Awesomely mod friendly, and they have a freekin great tech that used to work for Turner motor sports, Rick. This was the first time I was actually called into the service garage and got to sit and talk to the tech about my car while he was working on it. Awesome experience.

Any way Rick found out that 2 of my plug wires had far more resistance in them then they should have. We replaced them and I went on my way with my car running better then it had been for months.

At any rate, this brings me to my question. What the heck would make my oem plug wires fail at 44k miles. They showed no signs of corrosion on the wires and visibly were in perfect shape.

My next question is, will adding a thicker gauge of wires avoid this problem in the future by giving me a buffer zone for resistance to build up? I've always assumed as long as there was a way to make a spark... you were g2g... it appears i may have been wrong.

Even though I'm going to replace my oem coil pack I still seen no reason for after market coils. I just see no need to change something and risk messing with the electrical system when I could just replace with OEM.

So yeah... sorry about the overly long post and useless discussion about plug wires.


p.s. Sorry I doubted you Jan. I'm a believer no matter what any of the naysayers might say.

pp.ss. In case any of you were considering it... this car runs like crap as a 3cyl.

 

44k ain't bad for spark plug wires. Generally speaking (not just Mini), some wires wear out sooner while some last longer.

When plug wires go bad, most of the time it is the wiring inside the silicon outer layer develops some corrosion (due to the elements - heat water particularly) which increases resistance [to carrying electrical loads]. Other times, some of the wires inside might break. This is generally caused by pulling on them improperly or stretching them.

Generally speaking, when you start running more boost, air and more fuel you often need to increase spark to light the fuel mixture appropriately. This is universal across any modded car. The factory ignition is designed for a certain performance range. Go beyond that and you may need to upgrade parts of the ignition system. Most people start with thicker wires (I'm talking about internal wires not just the silicon jacket being thicker) that may be of materials that conduct the electrical charge more efficiently. The next logical step would be coils assuming the plugs being used are a good heat range for the mods and tuning.

 

Like most other things on the MINI, BMW went with very inexpensive parts. So it looks like the wires are another one of those problem areas.

Have had my Kingsbourne wires for almost 4 years with no problems and a MSD coil for the looks for over a year now too.

 

Changed mine over to Demon Coil and Magnacor wires at 40,000 miles. Most spark plug wires are good for 4 years, but like spark plugs ( which the dealer says 100,000 miles ) are good for 2 years, for maximum performance. Aftermarket parts will not hurt your electrical systems. Buy good parts from reputable dealers and they will warrant their products as new. Better coil better spark, better fuel economy, better performance. Goes with any replacement part, always upgrade to a better part and get more fun from you car with less break-downs and more fun in the long run.

 

I went with MSD wires and coil, plus new NGK plugs, about 5000 miles ago. Got a nice boost from it. I've been using NGK since I got my pulley (to go a step colder). Checked the plugs at about 45000, and looked good, but a bit weathered. That was when I decided to upgrade the wires and coil. I used to accept the "any wire/coil/spark is a good wire/coil/spark" philosophy. No more!!

 

i agree, its just something that can happen. some will last longer that you, others wont. they can crack, oxidize, the outer layer may get minute cracks and allow the spark to jump to ground, the spark could also leak out around the plug if the plug is cracked, or moisture gets around it.

On my hot rod engine, with they style of plug attachments i got on it, if the motor gets wet in the rain, sparks will jump all over the motor. hahah, looks kind of cool actually.

Beecher