First some backgroung info...My car had been idling rough and cutting out. I thought it was the map sensor problem. So I took it to the Dealer and they couldn't find a problem. Said it might have something to do with the VAFC. So I checked all the connections with the VAFC and tightened a couple. Problem still there. I decided to change out my spark plugs just to see if that helped. Turns out it was the problem.

Now here's the weird thing...I was checking out the plugs and upon inspection I found the plug I pulled out of cylinder 1(front of car) was wobbly. The white (ceramic?) part rotates independently of the rest of the spark plug. I never dropped the plug or did anything to damage it. Only thing that ever happened was that I ran over a series of bumps on the same day it happened. That seems to be the cause of the problem but I'm confused about how it could happen. How can a spark plug INSIDE the engine get broken like that?

 

Sounds like a defective plug to me. This is the first time i have heard of this. Any pics of the plug?

 

Sorry, no camera. But if you come out on a Sunday or Wednesday, I'll have it in my car if you want to take a look.

 

Was it an Iridium plug or a factory one (i.e. when did you update your sig )? If it's factory, bring it in and show the dealer. If it's Iridium... I don't know what recourse you have but I know it should at LEAST get you a new set of plugs. The mfr. would probably love to see them so they can prevent it from happening again.

 

You mean to the dyno day at Pro Dyno Research?

 

Defective plug, probably "broke" when it was put in due to a weakness in making it, then the bump caused the break to start seperating (ie, wobblying) and you noticed it.

 

I suggest you replace for some new spark plugs(depending on how many are damaged).

 

They're the iridium ones. Just one screwed up. I've already replaced all my iridiums with the stockers. I'll try and get ahold of Denso and see if I can get some new plugs. Thanks!

 

SOrry to reply so late, Ive been sleeping. Ive found plugs break from time to time its not a common thing but it does happen.
Was that your car I worked on that day? I may be losing my mind so if it was you Im sorry I couldnt find that problem for you.

 

If this was indeed the problem and your dealer failed to pull a P0301 code off the On-Board Diagnostic System.....I'd be looking for a new dealer .

Utah