For the LR mechanics

[alaskanseminole]

I purchased a full set of NGK plugs for my 2005 Mazda in December 2014. I installed them properly using the correct amount of torque and I did NOT drop, gap or over-torque them during installation. I've been installing my own plugs for over 25 years.


This past Wednesday I experience a sudden power loss followed by engine miss. Since my mechanic was closer than my garage, I took it straight to him. What he found was quite shocking. The center electrode as well as the ground electrode came off of the plug inside cylinder one. After several compression tests, a bore scope analysis and re-install of a new replacement plug, it appears to be running smoothly again.


Here's my concern, though, we couldn't find any of the broken piece(s) of the plug. It is possible they broke down and worked their way out through a valve or they could be lodged inside the head, piston, etc. There's no way to know unless we tear down the engine.

What would you do? Roll the dice and just drive it or pay for the peace of mind?


I wrote NGK to get their input as well.


NOTE: Yes, I fully realize the bigger problem here is, "2005 Mazda", but it's paid off and I don't really care about driving a flashy car.

NOTE: Yes, it has rims.

This post was edited on 2/19 8:27 AM by alaskanseminole

 

[Finance85]

If the pieces did not burn up, they can only be one of 3 places -
still inside the cylinder, which is unlikely
exited through the intake valve, which is unlikely
exited through the exhaust valve

Since you've already cranked it and run it, if the pieces were still in the cylinder, or tried to exit through the intake valve, you would know it. If the pieces were stuck in either valve you would also notice it.

It seems likely the pieces either burned, or exited through the exhaust valve.

That's all IMO.

 

[alaskanseminole]

Originally posted by Finance85:
It seems likely the pieces either burned, or exited through the exhaust valve.

That's what my gut says. It's running exactly as it should. Weird (and lucky).

 

[F4Gary]

You would have seen the pieces when you borescoped it. I say they went out the exhaust valve. How did the top of the piston look? It may have damaged the valve seat, but you would hear that in the exhaust kinda like a burned valve.

I'd say you're good to go.

This post was edited on 2/19 10:29 AM by F4Gary

 

[alaskanseminole]

Originally posted by F4Gary:
You would have seen the pieces when you borescoped it. I say they went out the exhaust valve. How did the top of the piston look? It may have damaged the valve seat, but you would hear that in the exhaust kinda like a burned valve.

I'd say you're good to go.

Some carbon build up on the piston head, but didn't look too bad. They recommended a fuel injection cleaning service ($150), but my concern would be breaking large pieces of carbon off and making matters worse.

 

[cmanole]

Originally posted by alaskanseminole:

Originally posted by F4Gary:
You would have seen the pieces when you borescoped it. I say they went out the exhaust valve. How did the top of the piston look? It may have damaged the valve seat, but you would hear that in the exhaust kinda like a burned valve.

I'd say you're good to go.

Some carbon build up on the piston head, but didn't look too bad. They recommended a fuel injection cleaning service ($150), but my concern would be breaking large pieces of carbon off and making matters worse.

You need to put a bullet in that thing man...

 

[alaskanseminole]

Originally posted by cmanole:
You need to put a bullet in that thing man...

Are you serious? I am the only owner and know that vehicle inside and out. The mechanic said the car looks like it just came off the show-room floor and (I quote) said, "It would be heartbreaking for your efforts to be in vain over a $2 spark plug."

My goal has always been to see if I can get $200+ miles out of it.

When I want to drive something "cool" I drive my wife's Pathfinder LE on the weekends.

(we're about to trade that in on a Grand Cherokee Limited, though)

 

[cmanole]

Originally posted by alaskanseminole:

Originally posted by cmanole:
You need to put a bullet in that thing man...

Are you serious? I am the only owner and know that vehicle inside and out. The mechanic said the car looks like it just came off the show-room floor and (I quote) said, "It would be heartbreaking for your efforts to be in vain over a $2 spark plug."

My goal has always been to see if I can get $200+ miles out of it.

When I want to drive something "cool" I drive my wife's Pathfinder LE on the weekends.

(we're about to trade that in on a Grand Cherokee Limited, though)

I hear you. I drive a 2000 Tacoma so I have no room to talk. I'll buy a new truck one day and when I do it will be raw...

 

[MuchasVeces]

The freaking driver's side sun visor on my Subaru just broke. It just kinda dangles there, limply. 70 bucks to order a new one online.

 

[alaskanseminole]

Originally posted by MuchasVeces:
The freaking driver's side sun visor on my Subaru just broke. It just kinda dangles there, limply. 70 bucks to order a new one online.

Gotta get that fixed! That later afternoon drive into the sun will make you nutz without it!!!