Cracked Ignition Coil

[stanigu]

So I got CEL code indicating misfire on cylinder 4, and the car was hesitating on low RPM under load.

I had replaced all the ignition coil less than 1000 miles ago with Beru coils. I pulled the one from cylinder 4 out, and saw that it was cracked badly!

I replaced it, and the car runs fine now. But I was wondering what might cause this...just a defect, or is there a root cause that I should look into?

[clickman]

Yikes! Is that the new bigger style? I bought a set a year ago and haven't put them in yet...

[911monty]

[QUOTE=stanigu;546128]So I got CEL code indicating misfire on cylinder 4, and the car was hesitating on low RPM under load.

I had replaced all the ignition coil less than 1000 miles ago with Beru coils. I pulled the one from cylinder 4 out, and saw that it was cracked badly!

I replaced it, and the car runs fine now. But I was wondering what might cause this...just a defect, or is there a root cause that I should look into?



Hard to tell from your picture, but that kinda looks like it was not seated properly on the plug then tightened down with the plug hard against the edge of the extension opening and the localized pressure caused the fracture. Is the extension straight or bowed? and is there any indentation at the point of the crack? Anyway that appears to be a stress fracture and not a defect. My .02.

[thstone]

Wow, I have never seen anything like that. Cracks in coils are usually hairline cracks - that looks like the Grand Canyon in comparison.

Can you post another photo that shows the tube portion of the coil in clear focus so we can see the detail of the crack itself?

[bwdz]

That looks like installer error more than a part defect. It looks like the tear is from twisting so it was probably not seated properly and no dielectric grease used and it tore when tightening down.

[kk2002s]

My same question - are those the updated thicker body coil packs?
I replaced mine about a year ago with the thicker body type. I felt they never did seat well. I felt I could have continued to tighten the bolts but I stopped when they were sufficiently tight enough using handheld hex wrench

Now I think I need to pull them out and examine them

[stanigu]

Installer error is a definite possibility, since I was the one who did the work (late at night too, I might add). And Cylinder 4 is the one that is tucked away towards the front with that dang hose getting in the way.

They are indeed the new "thick" variety. I'm surprised that the car ran at all with that huge crack. The only noticeable problem with the performance was at low RPM at high load.

[stanigu]

Originally Posted by thstone

Wow, I have never seen anything like that. Cracks in coils are usually hairline cracks - that looks like the Grand Canyon in comparison.

Can you post another photo that shows the tube portion of the coil in clear focus so we can see the detail of the crack itself?

For your viewing pleasure (viewer discretion advised....)


[IMG][/IMG]