[ET160]

I would try to further assess the broken off electrode. You don't want it the cylinder. Can you get a good look in or borrow or buy a borescope ?

 

[aerojon]

misfiring is not good as it can let raw fuel into the cat = fubared cat..

 

[EdT]

Is the Check Engine light on? If so, have you checked the codes?

I am wondering if the ECU has gone bye-bye. Running really rich is a classic failure mode.

 

[Baab-Saab]

Please tell me that electrode did not break off into the cylinder.
Whats the status on the coils?
Sometimes when the T8 Ecu fails, the injector drivers will stay on causing it to dump fuel into the chamber which can foul up the plugs like that.

 

[Bob12312357]

....the only place the electrode can break off is in the cylinder.... Interestingly when a spark plug is seized the shop tool to remove it purposefully breaks it, obviously the ceramic bits can't just be taken out with a magnet but the tip could be extracted by magnet if it hasn't been ejected already. If you're real lucky that occurred spontaneously with compression intact.

 

[napoleon solo]

Thanks for the replies folks.. Indeed the electrode did break off into the cylinder. As the car has been driven quite a number of miles in this state before I realised, I'd assume there was no catastrophic engine damage. However I wonder if it might have made it's way to the turbo, hence the noise..

Codes were only for a random misfire across all cylinders when the recovery guy scanned it. I have now taken it in to a Saab garage so will get the full lowdown shortly!

 

[napoleon solo]

Is the Check Engine light on? If so, have you checked the codes?

I am wondering if the ECU has gone bye-bye. Running really rich is a classic failure mode.

Yep That's what the garage suggested too. It's had other weird symptoms that might suggest the same over the last little while

 

[napoleon solo]

Please tell me that electrode did not break off into the cylinder.
Whats the status on the coils?
Sometimes when the T8 Ecu fails, the injector drivers will stay on causing it to dump fuel into the chamber which can foul up the plugs like that.

The coils are actually alright. I did a compression test just out of curiosity and the numbers are pretty good so hopefully no significant damage to the bores/pistons

 

[Mimmi]

Codes were only for a random misfire across all cylinders when the recovery guy scanned it. I have now taken it in to a Saab garage so will get the full lowdown shortly!

Do not be surprised if TECH2 founds bunch of real DTCs. Generic reader (what recovery guy usually have) will not read all DTCs.

 

[MPLsaab]

How do you know the coils are ok? First thing I would replace. And with Saab coils. Those plug electrodes look excessively warn out.