bloodvette

05 lariat 95,000 miles. I just did a plug change myself with the Lisle 65600 and 5 of the 8 broke. The display on the lariat model shows your average fuel mileage. when you reset it, it will show the instantaneous but begins averaging it and you get a good idea of your average mileage after driving for a week or 2. I would say my driving is 80% city, 20% highway for the following information.

after driving the truck for 1/2 a year, I observed my average mileage to be 17.5 Litres / 100km. which equals 13.3 Miles/gallon.

After driving for the last 2 weeks on the new plugs, my mileage is at 15.5 Litres / 100km. which equals 15 Miles/gallon.

I will keep an eye on this to see if it holds true, but that is a significant jump. There was a faint engine miss and a stutter that was cleared up with the new plugs. Also, I noticed that every plug I pulled had the electrode tip burnt down which made the gap much larger. I'm still trying to find out if thats normal.

j

CrashTECH

I don't think mine runs "rough" but I do think it could be smoother. I have about 88k miles now. Probably going to tackle this myself soon.

GATORB8

Damn, I need to get off of my butt and change mine. Plugs and the KTool extractor set have been sitting in the box from Rockauto for like two months.

jkurtz04

when the plugs broke, how difficult was it to get them out. i normally do most the work on my truck but ive been scared of the plugs becasue ive heard about them breaking like yours did. is it something where i just need to have a steady hand and take my time or are they just going to break no matter how steady i am.

GATORB8

The breaking plugs are just an issue with the 5.4L 3v motors, but it's not a steady hand thing, the plug's design allows for carbon build up to lock in the lower shaft of the plug. Here's the TSB: www.stangnet.com/images/stories/docs/s197_TSBs/08-07-06.pdf

EDIT: I see you have a 5.4 from your profile. Here's some reading on the issue: https://www.f150forum.com/f4/5-4l-3v...30-07-a-56871/

bigorangecntry07

what plugs did you put in.... the champion 7989s???

RR05f150

About the Champion sparkplugs I would rethink. I changed my plugs last year. I guest I got luckly no broken plugs. I ran some lucas thru the tank just prior. My mistake was buying the champion plugs. 13,000 miles later develope a miss 2 bad plugs. Took them out and put in some Motorcraft plugs no problems since.

maddog921

I agree with rr05...champion plugs are not the plugs they once were.
i have had bad ones right out of the box.

bigorangecntry07

i work at carquest auto parts so i can get a good deal on the either way but would rather go with a one piece plug.

bloodvette

no if it's gonna break it's gonna break. I think maybe engine temperature is a factor. The first day, I idolled the engine for 15 minutes then I did 3 and they all broke. The next day I drove for 1/2 an hour, and I did, 3 and none broke. The next day I drove for 20 minutes and I did the last 2 and they both broke. After the second or third plug that you extract you'll be fast at it. After a few extractions, if I had one break I just said oh-well and extracted it. it only takes about 15 minutes to extract a plug. The 3 that didn't break were different right from the get go, they also made a lot of screeching as they came out. the others were all silent.