Topic: Anyone else eat coils?

[van]

I have a 97 TJ w/185k on it.  ever since 100k, it used to burn through a coil every year or so.  Now it is killing them every couple of weeks/months.  OEM coils seem to last longer.  Anyone else come across this or have any ideas what could be causing it?  I have no evidence I am running hot at all.  No indication that anything weird is going on with voltage.

Thoughts?  It is rather annoying losing a coil in Jersey traffic...

[sharpxmen]

jfrabat here has the same problem, he has yet to find a solution (from what i recall), i'm sure he'll chime in with details

[grumpygy]

Think some of the tips he was given.

Check the grounds to include how it is mounted.  Make sure spark plug gap is not too wide.  From my experience make sure the coil is rated at the right Ohm for your vehical.  Some after Market are different and they change from one year group to another so the factory one could even be wrong if the parts counter guy looked up the wrong one.

[van]

Tx., Will do.  I actually ran a ground strap to the base of the coil, with little effect.  If excessive gap could overstress the coil, any chance that spark plug choice could do the same?

[grumpygy]

Tx., Will do.  I actually ran a ground strap to the base of the coil, with little effect.  If excessive gap could overstress the coil, any chance that spark plug choice could do the same?

I could not answer that but we have a few other folks who will answer it soon.

[sharpxmen]

i doubt the choice of plugs will blow up your coil but you can always run stock and see how that develops (easy and cheap test, and stock plugs run pretty good anyway). only difference in plugs is if they have an internal resistor or not but i don't think that can cause the coil to go bad anyway, otherwise if you keep the plug gap the same as stock (or as recommended if you're using an aftermarket coil) you should not have any problems.

What coil were you using that got damaged, was it recommended or just some random one you picked?

[jfrabat]

Sharp is right; I did have this problem, where I would eat up 2 or 3 coils a year (it got to the point where I always have 3 coils INSIDE the Jeep, just in case).  What has fixed (mind you, the Jeep is no longer my daily driver, so this could still creep up on me at any moment, so the coils are STILL in the Jeep just in case!) was to relocate the coil.  I relocated it to the firewall (right under the bar that holds the grill in place; in fact, I used the screw on the bar to hold the mount for the coil) for 3 reasons: (1) the coil was getting too hot from the engine, and I feel this is one of the reasons the coil was getting burned (I was explained that heat affects the conductivity or something along those lines, so if the coil was getting hot, it was more likely to burn, and the coil tended to fail on long drives, when it got hot for prolonged periods), (2) by taking it from UNDER the jeep and installing it up high there is less chance for water/mud to get into the connectors (and since all my wheeling involves both elements, it's better this way!), and (3) it's a heck of a lot easier to change the coil in this position than having to snake my arm around the exhaust in case I do burn it up again!

[van]

To the earlier question, I've eaten ones coming straight from the dealer, auto part store knockoffs, and one performance coil. 

I travel with only one spare coil (so far).  I like the idea of relocating it.  Come to think of it, the frequency of failure has increased since switching to an electric fan.  I suspect the reduced airflow all the time allows it to heat up and fail faster.  Mines on the non-exhaust side, but it is still a PITA to change.  I wonder how far forward I mount it.