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Tahoe_XC
06-11-2017, 09:46 AM
Go the call from the wife on the XC70: "I was going up a hill... the engine lost power and is really rough."

VIDA shows misfire in #3 and #4. Pulled the coils in both. #3 coil and spark plug aperture is clean. #4 is dirty full of carbon and the spark plug is loose in the threads.

Pulling the spark plug and inspecting suggests all threads are intact. However, the plug looks like:

8255

Any recommendations other than stick a new plug in and seeing what happens?
AKAMick
06-11-2017, 11:16 AM
Go the simplest and cheapest remedy first, replace the plug, or all of them and then see the results, then you address any issues it still has
hoonk
06-11-2017, 11:34 AM
the engine lost power and is really rough."

However, the plug looks like:

8255



The missing parts from the broken spark plug could have damaged the cylinder head or turbo :(
AKAMick
06-11-2017, 11:41 AM
The plug was loose so it overheated and burned away the electrodes, plugs need good contact with the head to in order to dissipate their heat otherwise they can overheat and vaporise the electrodes
Tahoe_XC
06-11-2017, 02:11 PM
Replaced the #4 plug with a Denso picked up a my local Napa. Everything seems to be good now. The bad plug is a Volvo and had 53K miles on it.... I think I will order up another set of Volvo plugs and replace all 5.
albertj
06-14-2017, 02:53 PM
Go the call from the wife on the XC70: "I was going up a hill... the engine lost power and is really rough."

VIDA shows misfire in #3 and #4. Pulled the coils in both. #3 coil and spark plug aperture is clean. #4 is dirty full of carbon and the spark plug is loose in the threads.

Pulling the spark plug and inspecting suggests all threads are intact. However, the plug looks like:

8255

Any recommendations other than stick a new plug in and seeing what happens?

Is the rest of that plug inside the cylinder bore? and if so , how'd you get it out?
Tahoe_XC
06-15-2017, 09:34 PM
Is the rest of that plug inside the cylinder bore? and if so , how'd you get it out?

My best guess: what ever is left is embedded in the cat matrix.....
AKAMick
06-16-2017, 06:50 AM
The temperatures in the combustion chambers away from the surfaces can reach 3600F so tiny remnants of metal can and most likely vaporise and be consumed and exhausted out of the chamber with no harmful effects, as the spark plug was loose and not shedding its heat to the cylinder head the tip mostly likely was being eroded and had not just broken off,