I have an 06 F-150 5.4. yesterday while i was on the highway i had the engine loose all power and it was vibrating like i was on a rumble strip. Was this the High Speed shut down? or do i have a bigger problem? if it was at what speed are they set at??? Thanks for your help.

 

The speed limiter is set around 98mph. Do you reach that speed?

 

i was around 90 to 93 mph

 

why abuse your truck like that

 

Running a F150 at 90 is not abuse.. The only reason for the speed limiter is due to the ratings of the cheap tires. No idea what your local laws are, but with 75mph freeway speeds and heavy traffic sometimes you need to run 90 just to keep from getting run over.

 

I concur ... here on the east cost ... I-95 is the sped limit as well as the highway name

 

Amen brother! I used to drive through Jersey on my way to MA from NC. If you think it's bad there you should go up to 195 in Providence RI. If you don't do 95 you'll get run off the road! Boston is just as bad. When I hit Providence i used to set cruise at 90 and roll. I would still get passed!

 

thats cool. Here in in california if you do 95 on any road that isn't private then your going to jail. Also speeds like that isn' t abuse on the truck. I would recamend a higher speed rated tire and sticking with the 3.55 gear ratios.

 

Hear in Jersey you always stay behind the fastest vehicle. Unfortunatlly out of staters don't know that the left lane is only to pass. You can get a ticket by the way.As for your question, do you notice dash and or head lights flicker on and off? I would have to guess its more than a tire vibration because the power would still be there. Something must be dragging down on the engine. My Ford Taurus had the rear lock up only at high speeds but that was front wheel drive. When you find the cause please let us know. Good luck.

 

K.O.T.O... THe reason it is happening is that there is a governor on it. There is a governor on yours too. It is usually 99 MPH then it shuts down. A tuner will eliminate this problem. Did the truck resume normal operation after slowing down?

 

the 1 and only time I ever hit the governor I was going 98 mph and the motor was cut back to idle until I had coasted down to under 90 mph.

this is just a guess, but I'm wondering if your truck did something similar to mine and instead of idling down, the motor may have accidently turned off. then you were just spinning the motor with the tranny and not the other way around. have you ever rolled your truck down a hill and dropped it into gear to start it? the sensation is similar to what you described

 

I was told by my dealer that the speed limiter or governer (the computer) was set to 99 to avoid law suits back to Ford from the owner of the vehicles or their families in the event of a serious accident. I checked mine with my GPS and it shuts off the fuel at 99.8 MPH. The computer will let you run 98 MPH all day long, but once you hit 99, that's it, no more fuel. The only way to do anything about it is to put a programmer on it. THIS WILL IN FACT VOID YOUR WARRANTY. So if you want to put a programmer on it and you are worried about the warranty, wait until your power train warranty is up first. If you have an extended warranty.........you know the rest. If though.....you were not all the way up to the governer yet, I would be concerned about another problem. Keep us posted.

 

Likewise, here in Connecticut, If you don't get behind the fastest vehicle , you WILL get run over. But we have so much ongoing construction forever here in this state, that you really can't get to high speed

 

99.8.....hum...rumor has it that mine is at 104

 

I don't drive that fast that often but I do know that when I did, my truck never shut done or coasted.