This post comes about a month after I my spark plug blowout post. I’ve put ~100miles of street driving on the plugs, and one autocross event.
You can already tell that cylinder #4 (left) has more carbon build up than the rest. The carbon build up seems to taper off as you go further towards cylinder #1 (right). It’s not clear what the cause of this is yet, but at least it seems to be consistent with the previous set of plugs.
I know stock miatas tend to be a little hot in the back of the block where cylinder #4 is, but I’ve got a coolant reroute that should be helping with that. Compression on cylinder #4 has always been the lowest, so it could be related to poor combustion from lower cylinder pressures. It’s been a little while since I ran a compression test, so I might do that.
The car seems to be running just as it normally does, so I’m not too worried.
-Dan
Load Comments