A little history on the car:
Bought at 90k miles.
91k miles system update required due to no start condition
91,874 oil change Mobil Synthetic
92k miles new Volvo brand spark plugs just because.
95,200 oil change Mobil Synthetic
95,300 oil trap/vent box replaced
99,302 oil change Mobil Synthetic
105,967 oil change Mobil Synthetic
110,893 oil change Mobil Synthetic
115,600 auxiliary battery replaced
116,231 oil change Mobil Synthetic
117,253 miles replaced fuel pressure sensor
117,785 miles cylinder 1 misfire, spark plug was broke in half. Replaced plug and ignition coil simultaneously. Problem resolved.
117,926 miles replaced rear evap core and recharged AC
118k miles currently. Now misfire on cylinder 3. Replaced remaining three ignition coils and all four spark plugs just for good measure. Problem NOT RESOLVED.
Cylinder 3 misfire code and rough running persists. If I unplug either the ignition coil or the fuel injector I’ve drawn arrows to in the attached picture, no change is felt in the way it runs. Any of the other coils or injectors unplugged will definitely change how smooth it runs. So it definitely seems to be isolated to the one particular cylinder. Of note, I did find a small amount of oil around a coil boot and spark plug while changing them all (although it was the second coil from the left in the picture with arrows). Valve cover gasket maybe? No misfire on that cylinder.
I’ve attached a picture of the oil level at the time of the misfire occurring as well as the engine system reduced performance message.
Just in case:
Vacuum reads 17 inches while running.
Engine temp 179.6
RPM 882
Thoughts on next steps? I’ve read some users reporting fuel injector issues. I could swap the injectors around and see if the misfire follows the injector from cylinder 3 to wherever I move it to. Any precautions or anyone advise against doing so? I spent 10 years in auto repair and am currently an industrial maintenance manager so I’m not above digging into this. I just left automotive long before SPA Volvo platform so I’ve not touched one except this one.
