Spark Plug question

captmello

Captain
Joined
Jun 30, 2008
Messages
3,829
My son and I replaced the plugs in his 99 Monte Carlo yesterday and found the old plugs to be a bit unusual.

He's a blurry pic
sparkplugpic.jpg


The old ones are AC 41-921. All the old plugs had the small tip comming off of the end instead of just being flat. Is that the way they are supposed to be or is this a symptom of another problem???
 

Bob_VT

Moderator & Unofficial iBoats Historian
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May 19, 2001
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26,022
Re: Spark Plug question

Yep.....plain old worn out....... That's quite the gap there and I bet the car runs better now. I had a Ford SHO that I pulled the plugs on and the gap was worn like that too.

Well..... you got your monies worth out of them!
 

Don S

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Re: Spark Plug question

That is the way they were made.

Untitled1.jpg

Untitled2.jpg
 

CharlieB

Vice Admiral
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Apr 10, 2007
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5,617
Re: Spark Plug question

Both small pieces are precious metal, making for a much longer lasting plug. Costly, but you get what you pay for.

What plugs did he use to replace them?
 

captmello

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Joined
Jun 30, 2008
Messages
3,829
Re: Spark Plug question

Thanks for that pic Don, Most of those tips had erroded away to little spikes. and looked more like points with material transfer or something.

Charlie, you're right of course, Platnum tipped. The replacement plug is different and does not have those tips...for that model year. However, the real truth here is that it is a junkyard replacement moter and my son does not know the year of the motor. The plugs were in the motor when he got it a few years back.:confused:
 
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