Cracks in ignition coils

[michaelluscher]

Instant grounds for replacement, even if it still works ok?
I swapped these out of the soon to be DD Fusion, because I'd prefer not to burn up an expensive catalytic converter
They've only got 40k on them, but they're approaching 13 years old

I didn't even notice that 3/4 of them were cracked, until I had them in my hands to swap
I'll take a test drive later, see if drivability is any different
But it ran on all 4 cylinders with no Mode 6 misfires
Maybe on a damp/wet morning, things would be different?

Separate scenario, OE Denso coils on a 2005 2AZ RAV4
Hairline vertical cracks down the stalk

Am I right to call a coil when I see something like this?
Or do I wait until complete failure or a drivability problem manifests?

 

[Astro14]

Stalk - or plug tube - cracks, absolutely replace. Check, though, some coils allow you to swap just that part.

That crack in the potting on top? Maybe…depending on cost and difficulty of replacement.

Coils can last a very long time. Some of the coils on the V70XC are original and have 295,000 on them.

 

[SHOZ]

When Ford came out with these on the Taurus SHO V8 they had big time problems with tiny cracks and misfires. When it happened closest to the MAF it would trip lean codes too.....

 

[oil pan 4]

Stalk - or plug tube - cracks, absolutely replace. Check, though, some coils allow you to swap just that part.

That crack in the potting on top? Maybe…depending on cost and difficulty of replacement.

Coils can last a very long time. Some of the coils on the V70XC are original and have 295,000 on them.

Yup if cracked or broken, replace. If there's a crack up by the low voltage end at least put some RTV on them if you can't replace them right now. It will at least stabilize the wires and keep the water out of them for a little while.

 

[berniedd]

Decades ago when I was into fixing cathode ray tube TVs, we fixed high voltage arcing and corona discharge (22,000 - 25,000 volts) problems by wiping corona dope on the high voltage leaks/arcing. I see the stuff is still available in Amazon. Protects up to 4,000 volts per mil thickness and can withstand up to 356 degrees Fahrenheit. Might this be also used for michaelluscher's problem?

 

[f355spider]

I would run them until you have misfire codes.

I have oem Bremi coils on my V8 BMW and they are 22 yo and 354k miles. I have replaced only two coils about four years ago that randomly failed and gave misfire codes. Preventively, I replaced all the plug extensions at around 240k miles (coil and extension are separate parts)

 

[Kira]

I would run them until you have misfire codes.

Maybe the cracks are your only warning.
I'd hate to be far from home when the arcing decides to start and burns a hole THROUGH the nearest aluminum.
Remote likelihood, you say? OK, wait for codes.

 

[researcher]

It would be the same thing on my Civic's distributor cap. A crack in that wouldn't be good either. Definitely nothing wrong with seeing a defect and replacing it. It's that many years old, it had a good run, time for a new one.

 

[f355spider]

Maybe the cracks are your only warning.
I'd hate to be far from home when the arcing decides to start and burns a hole THROUGH the nearest aluminum.
Remote likelihood, you say? OK, wait for codes.

Never heard of that with BMWs...but maybe with a Ford Fusion? I carry a spare coil, a code reader and a small socket set in the trunk. Takes all of 15 minutes to swap. Perhaps on a car where they are difficult to replace then preventive replacement is more reasonable.

 

[vavavroom]

I'd brush a layer of two-part epoxy resin over the cracks on the top of the coil. Plain, unfilled, and non-conductive resin.

 

[RooflessVW]

My Porsche ran like crap every time it rained - having the coils so close to the road spray really exposed the cracking insulation.

 

[Kira]

Would you try coating them as described above?

 

[oil pan 4]

If you can't afford to replace them all at least get one coil pack and keep it in your glove box.

 

[paulo57509]

The cracks in the potting may be OK....for now. I'd replace the ones with cracked stalks.

While they're not coils, the Legend had a plug wire that had a defect (crack/void) in the stalk. It caused an intermittent miss that went undetected with a scope. It was only exposed when I pulled the wire off the plug with the engine running and witnessed the arcing thru the stalk to the spark plug bore.

Records show the wires were in service for 10k miles; KEM plug wires. Replaced the whole set with NGK.

 

[michaelluscher]

Well, they got replaced (as pictured)
But for a temporary/fiscally restrained job, I'm gonna keep that epoxy or just RTV in the back of my mind

As this is a FWD I-4, the coils take seconds to service

A transverse V6 with coils under an intake plenum, now that's another matter

Thank you all for insight