Why do some engines suck electrodes out of plugs?

[maketracks]

Ok. By now, surely everyone has seen the plug this guy took out of the GMC today. Here is that plug, best shot.

Now, I know there was an explanation ventured in the other thread, but what all scenarios could yield the result of this blackened, no fire plug that effectively left me dealing with 5 cylinders?

I really want to pull the rest, I can't do it now because it is dark out, but let us discuss.

And for the guy predicting "I know a guy that works on engines and puts in used ones," it sure runs fine with cylinder number six back, whichever one is closest to the passenger front corner.. he also changed the plug behind that one, in that cylinder bank.

 

[mechtech2]

I feel sorry for his valves/seats and cylinder bores.
That ceramic is hard, brittle, and abrasive.

I think it's poor construction.

 

[maketracks]

Originally Posted By: mechtech2
I feel sorry for his valves/seats and cylinder bores.
That ceramic is hard, brittle, and abrasive.

I think it's poor construction.


As a point of reference, these were Bosch Platinum+2s. Unsure who thought it would be a good idea to put a plug like that in a 4.3.

So, now it has two CR43TS plugs, and the rest - whatever they look like - are those. I hope.

Coming home, it made a typewriter noise that was probably some kind of valve. Goes away when cold. I think I need new oil.

4.3s are TOUGH engines! 181.000 miles

 

[Chris142]

I always figured that detonation was the cause of that. It does seem to be more common with Bosch and Autolite plugs from what I have seen.

 

[mechanicx]

That's what I figure, detonation.

 

[beast3300]

GM 19,633,653

Bosch 0

 

[maketracks]

I found an engine about 10 miles west of Leominster, MA. I just need to figure out if it is the right VIN.

If you could get a used engine with low miles for $500, would you do it? Or, would you change the rest of the plugs on this one? It runs well NOW...

The engine I found is from a 1994 it says it has TBI it actually is not from a van, that one. Will it work? Why or why not? And how do I know what VIN is TBI and what VIN is CPFI on the 4.3 of 1993 and 1994?

 

[maketracks]

Also.. DO I have a timing belt, timing chain, or "gear drive" on this thing?

And how does an engine cause to "detonate?" What has to happen for that to occur...

Debating how well this engine will hold up, in the long run. It appears to run better with that cylinder getting fire.

 

[crazyoildude]

chain

 

[Shannow]

Originally Posted By: Chris142
I always figured that detonation was the cause of that. It does seem to be more common with Bosch and Autolite plugs from what I have seen.


Back in the days of carbs, leaded fuel, and russian roulette ignition advance, a longitudinal half insulator on the bosch plugs told you to back off a bit.

 

[mechtech2]

Another Bosch failure.

 

[antiqueshell]

More like the improper application used as opposed to the make of plug being the issue.


A critical aspect of replacing spark plugs is to ALWAYS use a plug with the exact same number of ground electrodes as the one that is OEM. aside from the other important factors, like heat range, length, and thread pitch.

 

[PandaBear]

Originally Posted By: antiqueshell
A critical aspect of replacing spark plugs is to ALWAYS use a plug with the exact same number of ground electrodes as the one that is OEM. aside from the other important factors, like heat range, length, and thread pitch.


It still shouldn't break apart inside the engine. Even with different number of electrodes, if the manufacturer put it on the application list it should not break apart (although fuel economy may not be identical).

 

[antiqueshell]

It looks to me like that engine might have been in less than decent condition as well. Look at the surrounding area on the outside of the plug .

It looks to me like it was in that vehicle for perhaps 200K miles or more.