I have a 2008 F350 diesel superduty that I use for work. Currently my truck won't go above 75 mph. As soon as I get a little bit over 75 mph it bogs down to just below 75 and let's me get back up to 75. About two weeks ago my top was 65 mph. While the truck is acting this way I can shut it down while driving and turn it back on and 90 percent of the time the issue mysteriously dissapears from anywhere between a couple miles on up to hundreds of miles and when it does it again I go through the same routine over and over. Yes I have changed both fuel filters. Air filter is ok too. I should tell you that this truck was involved in an accident that ended up requiring most everything under the hood and the interior dash on down was removed in order to fix the frame. Repairs were 14,000 and no.. the accident was not my fault. Needless to say I brought it up to the local auto parts store within a month of getting the truck back when I just started towing with it again and had noticed it was acting up and i had them check it. About 8 different codes came up but they couldn't tell me what was wrong but one of them did notice that a small small hose was missing (maybe a vacuum hose? Either way this seems computer related to me or i was also told that possibly there is a filter in the exhaust that could be clogged up with basically soot. Help! Frustrated and confused.

 

6.4L Power Stroke Diesel - Ford Truck Enthusiasts Forums Here is a link to the page for the 6.4 diesel, if that`s what you have you would probably be better posting the problem there.
Good luck.

 

sounds like a governor to me. most cars and trucks are governed at 75 or 80 mph, but some fleet vehicles are set at 65.

 

this truck is probably governed at 96 mph since it is personal and not a F450. There is an issue with probably the programming of the truck. This should be a follow up to your insurance claim and taken care though that.

 

Welcome to FTE Mal1974 Got you moved to the 6.4L Forum

 

It could be a governor or it could be going in to safe mode...if you post the codes it would help alot....i had this similar situation happen to me ....i could turn the key off and then on and it would be OK ....it turned out to be the high pressure fuel pump