Misfire CEL, Coolant loss, Rough startup.

[RiderX]

Hello, I’m experiencing issues on my ecoboost mustang:
P0303 Misfire with P0316, Misfire occurred first 1000revs.
Coolant loss, but when it drops to min line, it stops losing.
I ran engine on-demand test & get P1116 code ECT Sensor related.
Car is stock, only K&N drop-in and exhaust after down-pipe for better sound only.
Issue happened after cold weather.
Now CEL disappeared, maybe after on demand test?.

I’m planning to change head gasket, before this, glad to see another advices.

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[ice445]

Mileage?

 

[RiderX]

Mileage?

69500mi. Drives normally, CEL shown, unusual exhaust noise while warming (1-2min only)

 

[RiderX]

Update: CEL disappeared, I think cold weather is affecting some parts, like thermostat or ECT sensor

 

[RiderX]

Update: Head gasket blown, coonlant leaked into cylinder 3, spaces between all cylinder’s have fire traces. Maybe this helps someone in future.

 

[ice445]

Update: Head gasket blown, coonlant leaked into cylinder 3, spaces between all cylinder’s have fire traces. Maybe this helps someone in future.

Sorry, I was going to comment that based on your mileage it was most likely the issue. Cold start misfire that goes away is a pretty damning sign. Sorry about your luck, I wish this failure wasn't so common with these engines.

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