If you have the 5.4, you need to do a search on the subject and get educated about the plugs for the 5.4, 3v engine. If it's a 4.6, no biggie. If it is the 5.4, there is only Motorcraft and Autolite, same manufacturer.

 

This sounds like my cousin's situation about a year ago. He never modded his truck, and the maintainance records were top notch. He wanted to get about 12 years of service out of this truck, and it never gave him any problems until the mileage dropped about 2 mpg (he reported 18.2 to about 16). He tried different gas, filters, and tire pressure, but never broke 17 for awhile. The truck had about 65K on the clock, so we decided to change the plugs. He wanted to wait until the recommended 100K mark, but he did not know what else to do. The plugs looked really bad and took awhile to get out safely. In the end, the truck got 18.5 after changing the plugs. That's when I decided that Ford's recommended plug change was a load of crap.

This sounds like a perfect time to try the plugs. With a little research here and other places, you will want to be careful when doing this job. Good Luck.

 

Ahh... quit confusin' the issue with facts!

As usual - good point.

 

It's always been a load of crap - just like the O2 change interval.

It's even a bigger load of crap now - with the new, advanced, self-seizing plug design in the 3V's LOL!

Bosch designed those O2's - and they say 30-50k. Vetoed by Ford, of course so as not to upset the TCO applecart...

 

Thanks for taking the time from your busy schedule to set that record straight

 

Air filter obstruction maybe, check and see if you've picked up a leaf or something in your air box??

 

Say... now that you mention it, has anyone seen Built's neighbour's guinea ?

 

Which reminds me of a story. One of our work vehicles seemed to be sluggish. Long story short, we sent it in for service and when they opened the airbox (GM Vehicle) where the air filter is, there was a mouse nest in there. This vehicle did a lot of sitting though.

 

nope, air filter is clean.

 

Why don't you try backing your claim rather than attempting sarcasm?

Pfffttt...

 

Ok Grub


Care to show me where I said 1 of these items were responsible for his problem. I said they can play a role and I stand behind that.

 

I assumed that's what your implication was.

That's why I threw the word "individually" in my reply to you.

 

Look out boys, the handbags are about to start flying!!!

 

you might could attribute the change in mpg so drastic to bad math...how do you figure your mpg??? odo reading only??? onboard computer??? how many gallons put in tank???? was the truck flat or on incline while filling??? many variables....and the last best is how long has the drop been noticed???? just one tank??? it could be a mechanical or software problem indeed, but it could be a simple one of just math.

 

i really dont think the things listed here can drastically reduce your mpg so rapidly, im assuming it was a sudden drop, or are we talking about a loss of 3 mpg over some time, i believe in preventative maintenance, so even its not time, i would replace the fuel filter 10 bucks at advance auto for MC. change plugs to autolite ht-1... good luck, 90 bucks total from pepboys, oil and oil filter your choice...

does the truck feel more sluggish? rpms out of whack? pinging or other engine noise? hard starting? rough idle?