It wouldn't hurt to check the module cassette for cracks. I've never heard of spark plugs burning out an ignition coil.

Well...we've got 3 people here that have experienced the exact same thing, and there is NO crack in my module cassette either or the dealer would have replaced that as well.

Guess you learned something new here today. :lol:

If that`s true I think it`s time to contact Bosch have they all been on 06`s

Yep...I do believe they have been Mike. I know mine and TX-HHR's are both 2006 and I'm sure the same is true with Wackaloon. Contacting Bosch is an option I'm sure, but since dealer is covering the problem under warranty, what can they really do for us? Look forward to your input.

Didn't the dealer replace your ignition coil a couple months ago when you had the same issue? If so, they probably replaced the whole cassette as a unit. Maybe not, but it's worth checking considering your ol' buddy CJ had the same problem which you can check out on another popular HHR forum that I believe you're an admin for. Not to mention you also stated in the same thread on the other forum that YOU had a "slight" crack in your cassette assembly too. Hmmm...

I had about the same problem with my +4s, I put my stock plugs back in.
rhoss1

Nellie's home :D She was towed to dealer by GM Roadside Assistance Wednesday evening, dealer got her fixed by 4:30 Thursday. Pretty good response from dealer IMNSHO.

Here's what the repair ticket had to say:

"Found PO300 misfire detected. Cyl. 2 and 3 both misfiring. Check spark. No spark at 2 and 3 coil. Test module. Found T terminals bent on module. Replace module. Still misfires. Replace coil assembly, for internal fault probably caused by loose connection at ignition module bent terminals. Test drive."'

All of which indicates to me that the issue was a probably a poor design on the connector to the module which led to the module failing and then the coil failure. The fact that they changed the design for 2007 models would tend to support this. It could also be a manufacturing defect in the module which led to the failures. It could also be an assembly line error, but 18009 miles of trouble free operation would tend to discount that.

So, there is some similarity between what happened to Nellie and what has happened to others with similar issues, however, NO crack in the module referenced by the mechanic, and he didn't change the plugs. I don't think my issue had anything to do with the Bosch plugs.

Bottom line: Nellie got sick, she went to the hospital, they cured her at no cost to me within a reasonable timeframe.