Driving my truck when doing 70mph the truck slowed down on its own. it felt like someone came from behind and hooked a heavy load on the back. so i pulled over and the truck started shakeing (idleing VERY rough) i then shut it off started it back up and drove off fine then about 3-4 miles later it did the same thing. Does anyone have a clue to whats going on?????????

02' F150 V6 2 wheel drive

 

Check to see if your leaking water, That happened to me in my Expedition on time, and I lost power, and had a rough idle, I ended up blowing my water pump. check to see if you have any water.

hope this helps

 

I checked can't seem to find any kind of leaks ex: radiator full. Thanks for the help

 

When it started slowing down, were you still giving it gas, and trying to accelerate?

 

Yes i would still go but with alot LESS power

 

I would check all of the simple stuff first... like my dad would always say "Son, air, fuel & fire, thats what an engine needs to run"... Make sure the airways are clear, none of the plug wires fell, or burned off, and to make sure you're engine is getting fuel..

 

Sounds like a typical misfire.

Steve

 

I just fixed the problem on my F150 98, 5.4L I had the problem for six months.. changed the fuel filter..nothing, changed all eight spark plugs nothing, changed air filter nothing, and here what the dealers say, O your coils are bad, ok, so i went and bought eight new ones, installed them myself, dont know how... nothing.. so I went to them again, told them what I done, they tried to get me for 800 bucks, I said what you doing to it, u need new fuel filter, fuel pump..... ladies and gentle men, its the MAF mass air flow sensor was dirty, please do not get fooled by these guys, they charged me 200 bucks to clean it, and if, I say if I had known that was the problem, I could of done it in 30 mins, if your truck starts to bog, no power, shaking, get the MAF cleaned first.... here is a link on how to do it, www.berrysweb.com/clean_your_maf.htm, good luck my truck runs like new again.

 

when was the last time you replaced your gas cap? my truck had similar symptoms as yours except i kept smelling gas fumes--do you smell gas fumes when you're at idle, or right after you shut off the engine and get out of your truck? Anyway, the seal on the gas cap was broken. I read in a chilton manual that the whole fuel system is pressurized, tank and all, and you may experience "a drop in power and/ or acceleration if our fuel system is not properly sealed." I changed the cap, and my performance went back to normal. hope this helps.....

 

Sounds like your cats to me / maybe an O2 sensor..possibly a bad coil or misfire, with the way you descibe it I'm thinking your cats are heating up - this effects your injectors believe or not - there linked as a preventative to protect your cats from damage, lol , not sure how that works in reverse. I would get a scan for that one if nothing is evident and you don't have a MIL.

 

Sounds like the PCM thought the engine was overheating and went into fail-safe mode. Check the PCM temperature sensor.

 

Don't bother looking for any signs of overheating like gage on dash... lol
Throw a bucket of steam on your engine it may help or maybe its the horizontal isolator, or the MAF bearing needs cleaning....

 

We don't need your bs here. We can go to the dealer for that!