Intermittent Rough Running/misfire - No fault codes

[Darbshaw]

I had this issue on my car, it wasn’t until I replaced plugs and coils, did my vanos, fuel pump etc. Eventually I finally took the time to do a compression test and found I had a blown head gasket. I know mine is a worst case scenario but I had enough with trying to chase down all the codes and that pesky misfire that kept coming back. I did also have a engine coolant temp implausible code but I don’t know if this was relatable to the issue


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[sapote]

It's hard to say due to no codes (P0128 means coolant was too low temp could be thermostat always opened but this shouldn't cause the rough running). Remove all plugs and show good pics of the tips.

[Ianb]

My car has been suffering from intermittent Rough running/misfire, makes no difference if it's hot or cold, it just comes and goes, not sure how to describe it apart from it feels flat when driving at normal 2-3K revs and the vibration can be felt and heard even when letting off the throttle and slowing down.

The only fault code I have is a shadow/pending P0128 which seems to point towards the thermostat, or if not the coolant temperature sensor.

Can plugs/coils cause this?