Smashed Spark Plug

[Shibbershabber]

SO this is not on one of my Chevys, but I know you guys have all the answers so Ill throw this out to yall


Got a project truck for my son... super clean 91 Mazda B2600 4x4... bought it not running, PO doesnt know why never had it looked at.


Pulling the plugs out today, I found one cross threaded ... really who the Fu@& rams home a spark plug after getting resistance? Probably used an impact? ANYHOW... moving on, the 4th cylinder's plug was DESTROYED!

Never seen one like it.



I checked the model info against the others, its the same plug as the rest, so its not longer, etc.
Also checked the # and it appears these are correct for this engine. (Bosch FR8LCX)


What can cause this to happen?

What can be done about it?

Is there something I can do to test anything or just try to get any debris out of the chamber and stick another plug in there?

Does it appear mechanical or could this have been a failure of the plug?


PO stated that the truck died while on the highway and he just had it towed home and posted it for sale.
Not entirely sure about that... oil looks like its been changed and not driven since... its clean, looks like canola oil on the dipstick.

Engine turns over okay without any odd sounds, etc. even tries to chug a bit but obviously wont start with a dead cylinder.

Thoughts?

 

[wjburken]

SO this is not on one of my Chevys, but I know you guys have all the answers so Ill throw this out to yall


Got a project truck for my son... super clean 91 Mazda B2600 4x4... bought it not running, PO doesnt know why never had it looked at.


Pulling the plugs out today, I found one cross threaded ... really who the Fu@& rams home a spark plug after getting resistance? Probably used an impact? ANYHOW... moving on, the 4th cylinder's plug was DESTROYED!

Never seen one like it.

View attachment 272708

I checked the model info against the others, its the same plug as the rest, so its not longer, etc.
Also checked the # and it appears these are correct for this engine. (Bosch FR8LCX)


What can cause this to happen?

What can be done about it?

Is there something I can do to test anything or just try to get any debris out of the chamber and stick another plug in there?

Does it appear mechanical or could this have been a failure of the plug?


PO stated that the truck died while on the highway and he just had it towed home and posted it for sale.
Not entirely sure about that... oil looks like its been changed and not driven since... its clean, looks like canola oil on the dipstick.

Engine turns over okay without any odd sounds, etc. even tries to chug a bit but obviously wont start with a dead cylinder.

Thoughts?
View attachment 272709

I’d pull the heads and see what’s going on.

 

[Shibbershabber]

I’d pull the heads and see what’s going on.

Other than visually inspecting the piston, what am I looking for

 

[wjburken]

Other than visually inspecting the piston, what am I looking for

That’s about it. If you have a endoscope, shove that in the plug port and take a look.

 

[Shibbershabber]

So worst case is the surface of the piston is damaged and needs to be replaced?

If the piston looks acceptable, then I don't need to worry about anything in the bottom end?

Otherwise I can get a new head for a few hundred bucks and be done

 

[Doubeleive]

I would do like wade suggested Grab a scope from harbor freight or ebay (they have usb ones cheap)

 

[wjburken]

I would do like wade suggested Grab a scope from harbor freight or ebay (they have usb ones cheap)

Here is what I own. Works great.
https://www.harborfreight.com/high-resolution-digital-inspection-camera-with-recorder-61838.html

 

[Shibbershabber]

Got one ordered...

Will look and see if its worth tearing open


Thanks

 

[Jimmyy]

Here’s a cheap usb one

https://www.amazon.com/Endoscope-In...&keywords=USB+endoscope&qid=1615090198&sr=8-8

 

[Shibbershabber]

Would those be good enough to examine the cylinder wall?

I wonder how good the resolution really os