1999 F150 Ext Cab, Short Bed, XLT 4x4 Off Road, 5.4L V8, auto, 83k miles

OK, so I just finished wiring the rest of my truck, mounting the winch selanoids I had left hanging two months ago when I mounted the winch, hid my LED wires, changed the oil to synthetic Mobile, and ordered a new tire to replace the one I blew last week. So, everythings going great!

I wish... on the way home from the Fire Department, my truck felt like it blew out a tire. It bounced and hopped; but only when I was accelorating moderately. When I floored it the bucking went away, and when I let it coast, it did the same (but it did slow quickly, but that might be becasue the computer is still learning b/c I had the batt out of the truck for about an hour). 10 miles later, its doing it all the time as long as I'm giving it gas. It still goes away when I accelorate hard. I stopped, check the oil, my tires, and the driveshaft, and all looks good. Oil is exactly where it was this morning after I filled it, tires are fine, driveshaft isn't obviously broken.

It did store a code when it first started acting up, and the check engine light is on. I will bring it to the shop tomorrow, but I am hesitant to drive it faster than 30mph, as it starts to really rattle around 40. Any ideas as to what this is? Is it safe to drive, or should I have it hauled? Thanks...

 

your truck sounds like what mine did last week i lost a cop coil on plug take it to auto zone or ford and have computer read

 

Sounds like a failed COP. Did it get wet under the hood?
It may just be bad timing and it happened to die when you were working on the truck.

 

Nope, not that I know of... I did spill some oil, but I always do, and this time I spilled less than usual...

Come to think of it (as I read the section on head gaskets... ) it has been burning plenty of oil lately... almost half by the time I change it (4k miles) I know, I should have been checking it, but its a recent development. And it doesn't have any odd smoke, nor odd smell, except for the spilled oil.

 

Is it safe/good to drive it? The mechanic is 25 minutes down a highway...

 

OK, called the dealer, he "phone diagnosed" it as a plug or COP problem, and told me not to drive it if its showing signs, which it is. A tow truck is on its way (my friend won't use the car-hauler she has access to because she broke it and isn't allowed to haul cars with it anymore...) and hopefully I will have it fixed before tonight. :-/

 

Fill us in on what the dealer finds. Always nice to have more info on our rides incase we get the same probs.

 

Sitting in the waiting room, enjoying the wireless internet they provide...

 

There is a leaky coolant line which shorted out the #4 coil. $350 for the coil, all parts, labor, and a new stinkin clamp.

 

Nice find. Too bad it had to be at the dealers.

 

eh, I'm not sorry I brought it to them. I am far more impressed with the people there than any of the local shops. Apparently the problem was a common occurance with 1999 models... be aware all 99 owners!

 

one more question... would this problem have resulted in a loss of power over the last 3k miles? I've been noticing it, especially towing, and my milage dropped about 5 mpg when I installed my winch (about a month and a half ago, right around when I noticed the lack of power).

 

That could result in a mpg loss.I had to replace all of mine.And what i suggest to you is go to autozone or murrays discount auto and buy the rest and replace them.They didnt tell you is that they run in a series.So when the one shorted it damaged the other one and so on.I had a good friend at ford tell me this.He said they just like to take more money each visit because next time it goes in they get that diagnostic fee agian...

 

Just reading threads. What is the cop? What is the coil?

Northsea
Just bought the 99 F150 4.6L auto 138L miles.

 

COP is the Coil on Plug, aka the new and highly (lol) reliable spark plug triggers that the 4.6 and 5.4 L engines use. Most of the time they are great and HIGHLY reliable, but when they fail they go out with a bang and are a PITA to replace. (and not so cheap either) Someone else will have to explain their exact job, all I know is they fire the plugs.