cracked spark plug...TWICE????

[randyj68]

I just bought a 98 Expedition XLT about a month ago, has the 4.6....developed a cylinder 4 misfire......of course the easiest one to get to. The plug ended up being cracked, replaced it, drove about 300 miles, check engine light came on and low and behold...cylinder 4 misfire and guess what...cracked plug. Wondering if my luck equaled buying a cracked plug or what else might cause it.

 

[Bedrck47]

normally number 4 is one of the hardest to get too

kindly explain where you feel number 4 is

 

[stamp11127]

Usually a cracked plug results from a side load while being torqued.

 

[BIG GREEN FORD]

Over torqued like stamp said

 

[randyj68]

I of course was being sarcastic about number 4 being eaay to get to. I am definitely no expert mechanic. .....but couldn't think of any reason for it to crack/break other than over torque or something. ......dumb question in general I guess........just figured id see if this was common or had happened to anyone other than me.

 

[BIG GREEN FORD]

Yes It has happen to me but it was #8 cyl put grease on the threads and tighten by hand it should turn easy at least 3 full turns by hand then torque to 12 ft lbs

 

[Bedrck47]

I figured you were being sarcastic or at least hoped so. But there was a post a while back in which someone believed all the even numbers were on one side and the odd numbers on the other side.
Normally when a plug gets cracked its because the socket wasn't straight on the plug or was tilted when being removed just over torqueing a plug as long as everything is straight won't cause the plug to crack or another way is by using a non spark plug type socket

 

[randyj68]

I normally do my own work...but in all honesty I didn't want to do this job. I'm hoping these guys I had fix it didnt rush and took care of it...... guess I'll have to get motivated if it happens again and do it myself. Or say it's time to sell/trade.

 

[seventieslord]

Test.... mod delete please