Hey guys,

Just wanted your thoughts on my replacement situation. My F150 is at 105k. At 88k, the #3 cylinder plug blew out needing a helicoil repair. At that time, the mechanic replaced plugs 1-4. I have just passed the 100k plug replacement interval. Do I now a) replace just plugs 5-8, or b) replace all 8. Thanks for any thoughts on this.

 

I myself would replace all, just to be safe.

 

I would replace all of the spark plugs as well they aren't very expensive. The majority of the cost will come from labor and finding someone who has the equipment and knowledge to change the spark plugs properly. In my experience (Proud owner of a 01 F150 triton 5.4L) some mechanics have no idea how to reach them. So just have them all replaced while your at it to save you money in the long run.

 

Unfortunately, the funds are not there to have someone do it and must do myself. Good to know the plugs are not that expensive so I will probably do them all. Thanks. Is it necessary to replace boots, wires, etc when doing the plugs?

 

Whether or not you need to replace the wires boots etc... Depends. Anyways I found a video that may help you replace the plugs and get an idea of what you will need:

 

BTW, does anyone know whether the 5.4L Triton in a vehicle like my '99 F150 has the 3 valve head and whether the head is cast iron or aluminum or how can I tell? Thanks.

 

3v's didn't come out until '04, heads on the modulars are aluminum.

 

Sorry, what do you mean by the modulars? Thanks.