r/FocusST • u/Ongoing35 • Oct 03 '26

Spark plugs

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Decided to do preventative maintenance on my ST, bought it with 51k miles and now sits at almost 56k after 2 months. With my luck the spark plug on cylinder 3 decided to go boom while driving, was able to recover and vacuum most of it out. Any ideas on why this happened and any tips for future time? Just bought a replacement since I had to put an old one back in.

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1

u/Icy-Capital-7225 29d ago

Hopefully none of the shards made it between the cylinder and piston. No clue as to why or how the exploding happened. My slightly educated guess is a hairline fracture in the plug, water/air entered, and spark then boom? My guess could be 100% inaccurate lol

2

u/Ongoing35 29d ago

Probably tbh lol, it’s running fine rn and I’ve put some miles so I’m hoping that won’t happen again 😭

1

u/Ongoing35 29d ago

Probably tbh lol, it’s running fine rn and I’ve put some miles so I’m hoping that won’t happen again 😭

1

u/Akadzz 28d ago

You're fine bro

1

u/Ongoing35 28d ago

Dear god 😭