Question: Bad spark plug? [Archive] - Forum


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04-12-2008, 07:56 AM
Have a strange least I thought it was kind of strange. I recently had the LIM, and water pump replaced on my 2000 GT. Both as PM, since they were still fine...but my car has 98k on it and I wanted them done before any potential issues. I had them done by a guy who has done work for me in the past and that I trust. He does good work, and knows his stuff. I got the work done for pretty much just the cost of the parts too. When he was finished with everything, he started up my car and the engine was mis-firing. We switched to different wires and nothing changed. He found out it was from the #5 cylinder, and ended up it was a bad plug. The plugs were almost new, only maybe 500 miles since I changed them, but as soon as we put in a new plug the mis-fire was gone and the car is fine now. I know the LIM and water pump job had nothing to do with the plug issue, and the car ran fine when I drove it to his shop for the work. I don't think I've ever heard of a plug being/going bad, unless it maybe was cracked or something. They were just regular Champion plugs, which I've used on all my vehicles for probably 30 years. Anyone ever hear or know of a plug being bad like this? Or know of something like this happening? Just a weird coinceidence? Thanks.

04-12-2008, 12:27 PM
use only ac delco platinum plugs or ngk iridium, those are the plugs that you are supposed to use.

04-12-2008, 12:41 PM
What brand of plug? Bosche Platinums are a plug that can often lead to a misfire. Some GMs don't like them.

04-12-2008, 12:55 PM
As it says in my post, they are regular Champion plugs. Been using them forever, in all kinds of vehicles, and never had a problem. Never thought it was worth spending $50 for those top of the line spark plugs. Why would they make such a difference?

04-12-2008, 02:17 PM
I have had the same problem with Champion plugs. The ceramic on one of the plugs had little spider web cracks. Looked like tiny black cracks all over it.

04-12-2008, 05:00 PM
Ok...I'm going to swap them out. What kind of plugs are some of you guys using? Recommendations?

04-12-2008, 05:14 PM
i'm using the 1.88 a plug NGKs they sell, no problems yet and iv had em in for a year now.
theres really no need to go into an iridium plug i dont think...

04-13-2008, 12:01 PM
I use NGK V-powers that are like 2 bucks a piece and i have had no problems. That 8 bucks a plug **** is not work it