I bought a 2005 MCS about two months ago, about a week ago it started to have idle/starting issues when its around 85 degrees outside. After i purchased the car i checked everything out and the #3 terminal on the coil has a small amount of corrosion on it. Could this be the cause of my issue? My car is stock other than M7 intake so far. If anyone has any info i would greatly appreciate it!!! Thanks!!

 

but it wouldn't hurt to clean the terminal, and if you can get to it, the inside of the connector for that plug cable.

Try new sparkplugs?

Which M7 intake?

Matt

 

I'm with the Doc on this one. Clean the corrosion, replace the plugs & I'd add a set of new plug wires. I'm curious how many miles you have on your MINI.

 

from personal experience it doesnt totaly get rid of the problem. The problem is also by no means unique to your car. Mini has a reflash avail for the comp but i wouldnt recoment it. a lot of members here have tried it with quite a few of them saying it made the problem go away....then come back worse. The corrosion is also not a unique problem at all. Either clean it or order a new one ( takes all of 5 minutes to change ) after use a dielectric grease on the end before replacing the wire. I do agree new plugs and wires wouldnt hurt and may even make the problem noticable less frequent. ( it did for mine)

 

is much more sensitive to plug tip condition that many know, especially if one has swapped to fine tiped iridium electrode plugs...

Also, our cars run rich and carbon build up is an issue, but this shows up more as WOT ping than rough idle. Search on "Sea Foam" for some details of how to clean the combustion chambers.

And lastly, idle can be effected by injector health. When I had mine cleaned (www.witchhunter.com) after just one year of use, it made noticable improvements in idle quality due to more even flow and improved atomization.

Good luck and let us know how it goes!

Matt

 

My car had 51000 miles and now has 55000. I purchased the whole M7 air box with godzilla filter . I tried to use a wire brush to clean the terminal and applied dielectric lube to the terminal with no improvements after. I read somewhere that 05 MCS has coil issues with #3? I think it could be the coil since it usually is affected by high outside temp, causing the coil to have higher resistance leading to an idle issue but no where near 100% sure. I seafoamed it as soon as i got it and it made a big difference, might be time again? Any suggestions on new coil and wires? Thanks for the replys and knowledge!!!!!

 

you may be able to find one in the marketplace. But I'm a bit surprised by the coil issues, as our cars use something called "wasted spark" ignition. This is where the spark is fired on the exhaust stroke, it helps a bit with emissions. that's why the coil is the shape it is and there are only three wires that go to the coil pack (coil A, coil B and return). If the spark plug wires are long enough, you should be able to swap a pair front to back and still have the car run the same.... But if it is in the body of the coil pack, the rough cylinder will move....

Also, it gets plenty warm under the hood anyway, hot days or cold.

Matt

 

I haven't experienced this, but a friend has. It was fixed at the dealer for a lot of $$$. What they did was replace the coil pack, the plug wires & install new plugs, problem fixed.

What they told her was she had a bad plug wire that caused the coil to fail.

From what I've gathered the OEM coil is a good one. You can usually find them for sale in the marketplace here for few $. I'm using a set of Kingsborn wires & they are fine, but IMO no better than an OEM set.

 

Doc I think you've nailed it. I didn't know that the MINI had a wasted spark ignition. My Miata has that & they are famous for eating plug wires. 30,000 is about all you can get out of a set on a Miata. I'm guessing the MINI may be in the same boat.

 

You can't really clean the terminals on the coil, as they are plated steel, and once the plating is punctured (usually by arcing) it will begin to rust and corrode no matter what you do. Replace it - you can get the MSD replacement coil (designed for the Neon) for about $70, and it has brass terminals, which can be cleaned if you need to.

The problem is most likely caused by arcing at the plug wire connector. You can try cleaning out the connector with a Q-tip and contact cleaner like Deoxit. Get all the black vaporized metal and metal oxides out, and then use a small screwdriver to bend the metal part inside the wire head slightly in to tighten the fit on the coil.

If fits right, you should be able to hear or feel a distinct "click" when you put it on the coil pin and push home.

This MAY fix or at least defer the issue. I'm still waiting to see if my #3 connection gets bad again after cleaning and tightening. If so, my next step will be new plug wires.

 

I really do appreciate all the extra knowledge and help on this issue!!! I think Im going to ohm out the wires and start with new wires/ coil if needed If there is any more information that you think would be helpful or something i would need to know im all ears.

 

Almost forgot....

Welcome to NAM.

 

i had a similar coil problem that manifested itself in a studder and eventual missfire #3 at 2800-3200 rpm. I'm currently on my 3rd set of OEM wires and 2nd oem coil... each time these parts are replaced the problem goes away for some time... typically only to come back about 9-12 months later.

55k on the odo fyi.