Third blown plug in three months

[jcims]

Hi folks,

We have our expy in the shop for the third time in as many months replacing a blown plug. It's an '03 XLT with the 5.4L and ~110K miles.

As we're only spending ~$350 per plug, it's still cheaper than replacing the heads, but it sucks spending the money. I don't know what the coil packs cost, but one thought was to 'fix' the cylinders that haven't blown while everything is still undamaged.

Any other suggestions? Thanks in advance...

 

[Cube]

I had the issue on my 01 Expedition 5.4 with 95K. What I did was totally removed both heads and did the timesert install. I have not had the issue since but then again my Expedition mostly sits in my driveway and only driven on the weekends or trips.

 

[green03]

did someone over-tighten the plugs on the last tuneup?