Quick question I have an 06 screw with a 5.4 flex fuel motor I have had all scheduled maintenance done on time per the manual so I'm having to drive about 800 miles a week now for work so miles are adding up fast 131,000 right now when do you guys think enough is enough and she becomes unreliable and how many miles do your trucks have on them aim hoping for at least 200 to 250 thousand before she starts to become trouble for me

 

Depends on what the word "trouble" means to you.

Talked to a customer a few days ago, '05 F150 with 5.4, he had just topped 300K miles. Cam phazers once, plugs ever so often, he considered them normal service. He bought a MC filter and 5W30 MC oil for an oil change.

 

I have a '06 250 with a 5.4 and mine has 318,085 and it runs and drives like the day I got it. Regular maintenance and being on time will do wonders

 

I had an 05 F150 FX4, lasted over 200k, and would have went longer if I had chosen to replace CATS.

 

Highway miles are almost like no miles. As long as you change the oil at probably 7500 mile intervals and keep your eye on everything else, you should be fine.

 

I'm at 188K now. Plugs at 75K and 150K. All other scheduled maintenance per manual. Blend door actuator a few years ago. Other than that nothing else except normal maintenance. I'm still running 5/20 Mobil Synthetic and changing at 5K intervals.

I would thing 200+ is easily attainable.

 

If you are using Mobil1, driving 800 highway miles a week and changing oil at 5000 miles, you are throwing away good expensive oil every six weeks or so. There's no reason you can't go 7500 at least.

 

I'm aiming for 300K... Good maintenance and no "stupid stuff" goes a lo-ooooong way.

 

I have 173,000 on my 04. Still running great, just did an tensioner pulley and cam shaft position sensor.

 

I think the motor was slightly different but my dad had five e-350s with the 5.4 and four of them were 400k+, almost all highway miles. The last one was totaled 200k.

 

How many miles is enough...depends on you & of course your driving & a bit of luck ...all 4.6 's & highway kilometers....my 02 went 647,000 KM's ran like a kitten!! changed with reg. oil @ 5000km religiously...done regular tranny oil/plugs etc. of course I change out the complete front end as needed...if you don't have the cam phazer issues I think you are good to go!!!!!!!!!! my 2010 right now is kissing @ 500,000 & purring but is a slightly different build on the motor...biggest thing both trucks I replaced entire driveshafts around + 250,000km's
PS: i also got $2500.00 cdn. on the 02 when I traded it in on an 08 for the wife.....

 

I might add after the 02 I bought an 07 with 5.4...it went 335,000 & then one day I was sleeping in it & I inadvertingly stepped on the gas pedal wide open for a couple of min. ..it took about another 600 km...to cause the cam phazers etc. to start ticking loud enough that the knock sensors shut down the power...I chose to replace the motor with a good used 09 5.4 ...I still got it & it is around 424,000 km right know & going strong although I don't need to really drive it now!!

 

My 04 5.4L just rolled over 551k miles today. A lot of highway miles and conventional oil changes every 5k miles. Only real engine trouble was a broken valve spring at 250k miles.

 

I've got two F150s, a 2000 with a 4.6 and a 2007 with a 5.4.
The 4.6 has 291,000+ miles on it. So far the only things, other than routine maintenance was a transmission, replaced under warranty, and the idle air controller needed to be replaced.
The 5.4 has just turned 219,000 miles and has had no problems at all, just routine maintenance.
Both have had conventional oil changes every 3000 miles. I started using 5W-30 in both once the warranty had expired.
I've changed the spark plugs in the 5.4 myself twice and have never broken any. The cam phasers are still quiet too.

 

I may be wrong but it seem like I read about a lot of phaser failures and valve train failures by 150kmiles. I have 105kmiles. I just replaced the injectors preemptively and the PS and tranny cooler liners lines preemptively. I have been planning on keeping it for only another 50kmiles. Should I reconsider and keep it longer?