Old Spark plugs...

[shizznats]

i replaced my old bosch platinum 4 plugs with NGKs today and this is what my old ones look like:

the one on the left came out really easy cuz its covered in oil...
and the one second from the right has a LOT of buildup , much more than the others (thats cylinder 1... where i got the misfire)... what is this a sign of? bad injector?

https://sl-i.net/FORUM/images/imported/2007/12/DSC04808-1.jpg


heres a closer look:

https://sl-i.net/FORUM/images/imported/2007/12/DSC04809-1.jpg

[dodik]

no its a sign of Bosch shitty plugs, i thought there was a thread somewhere on how shitty Bosch plugs are, i tried them in my old BD and the car barely ran thru in soem NGKs and everyting was great. build up like that can come from variety of situations old wires, wrong gap in the plugs, bad coil, bad gas/fuel filter. when i removed 100000 mile plugs from my old BD they had zero build up on them, gap was kinda big, but no build up whatsoever.

[MCarp22]

If your camera has a macro mode, i reccomend using it for close-up shots like that.


the one second from the right has a LOT of buildup , much more than the others (thats cylinder 1... where i got the misfire)... what is this a sign of?

Looks to me like the subaru's waste-spark coil setup eroded the platinum center electrode there. Because it's two coils, two of the plugs are fired with reverse polarity. With it eroded like that you're getting a weak spark and incomplete combustion.

Here's a +2 that I had run in my car for a short while:

https://sl-i.net/FORUM/images/imported/2007/12/bosch2-1.jpg

Notice how the center platinum has chunks missing out of it.

[dodik]

by the way have you ever tried using seafoam looks liek you have a LOT of build up most likely a lot on the pistons and valves too. i'd give a shot to some sort of cleaning solution.

[shazapple]

My car has run fine with Bosch platinum for 3 years (60k km)

Its probably a combination of old plugs and wires.