1999 F250SD, why?

kaiser715

kaiser715

Doing hard time
Joined
Jun 1, 2006
Location
7, Pocket, NC
Other than "because it's a Ford", what's my problem?

1999 F250 StuporDuty with 5.4. Last November, I was on the way to the beach, started running real rough and got it home. Didn't have time to mess with it, so took it to the shop. Only problem was the plugs were worn out. They had been in about 50k miles. (105k to 155k). Original plugs had lasted to 105k.

That's all they did to it back in November, just replace the plugs, and it's been fine. I forget what brand/type plugs went in, but the guy I took it to doesn't cut corners.

Today on the highway, truck all of a sudden started running rough again. Exactly the same symptoms as before, so I'm assuming plugs again....but it's only been 13k miles since replaced.

What's making it do this???
 
I've heard, and I know my parents have had the same type of problems with their saturns, that the brand of plugs and wires can make a huge difference in how long they last.

You may have to go buy plugs/wires/cap/rotor from the dealer.
 
On my 98 f250 w/ 5.4...I had real rough running issues too once...it turned out to be a bad coil (they are on the plugs on these).

Also stated above, the monkeys at advance, autozone, etc. would try to sell me cheapo plugs. The 5.4's will eat them up. Use platinum, and they will last 100k each time.
 
my 02 150 used to love eating the COP "wires"...At $200 a pop from Ford...it was a pain in the as. When i finally sold it, I kept 2 spares in the glove box at all times. Went through every one once and 3 twice...
 
I had issues with my truck and thought it was running rough....it really wasn't the motor though. Turned out to be the transmission and it was right at 50,000 and again at close to 100k. Changed the filter and fluid and perfect for another 50 k I assume. I've got the new coil on plug setup in my '01 and have never had issues with plugs even with 130k on it.

So, motor running rough or is it jerking like its getting off the throttle in spurts?
 
Jerking and bucking under throttle, like it's misfiring. After the first post, I drove it to the shop... did great, ran smooth up until I got on the highway, accel'ed hard up to 55, then it started...backed off, and it was fine. We'll see tomorrow what the damage is.

Actually, I already know what caused it...Saturday night, I was on the Internet...wife asked what I was doing....told here I was looking at trucks....I was at trucktrader.com looking to maybe replace with a lesser-mileage V10 or Diesel.
 
That definately sounds like the exact same problem I had. It was periodic (weather and tranny temperature related?) Try the fluid and filter change in the tranny and I am pretty sure it'll fix your problem.
 
MOTORCRAFT plugs only!!!Went through three sets quick until we changed back to the motorcraft. Also look at the cop set up alot of times a torn boot will led to the arc off to the inside of the hole for the sp. Have the truck scanned for codes and have a misfire test ran, not always will you have a code for a misfire.
 
Got it back today...no misfire, no codes, plugs good. They took it for a test drive, drove it to lunch, drove it on a parts run, no problems. I drove it home, got out on the highway, no problems.

We'll see what happens over the next few days and go from there.

Funny thing is, my mom has an 89 Blazer that my dad used to tow his boat, and she kept it around after he passed on, to use for yard stuff, etc. I had borrowed it while the F250 was in the shop. I was stopping by the shop at 5pm today to pay and get them to leave my truck outside. As I pulled into the lot, I heard a rattle, then lost power steering....fan belt broke. Pretty good timing, just picked mine up and left the Blazer and let them deal with it.
 
Pay attention and see if it gives more problems when raining.
Mine would only act up in rain...I still havent figured out the connection, but rain, and it would pop a COP module
 
F*rd had a problem with water draining on the cop from the cowl, remeber reading a bulletin on it. I'll call tomorrow and see if I can get anymore info.
 
I had to have 2 coil packs replaced on my old work Expedition with the same motor. It did exactly what you are describing, both times after heavy rain ( once during Hurricane Isabelle recovery efforts that included water fording WELL above the recommended depths...:driver:)
 
My old man's 5.4 issues turned out to be fuel filter.
 
Franklin said:
My old man's 5.4 issues turned out to be fuel filter.
Click to expand...


I thought my rough running F250 was a fuel filter too. Changed the filter but the truck didn't run any better...

Although, that was the cheapest/easiest to change, so I would recommend doing this first, it won't hurt.
 
Check and make sure the heater hose quick connect on the pass. side isnt leaking onto the number 4 cyl.coil pack. Have seen this to be a very common issue. Also, there is a vacuum elbow for the pcv system on the back of the intake that rots out regularly. Coil packs definately a common problem. By the way, I love my Duramax. Good luck.
 
I've gone about 500 miles since it crapped out, up to 85 on the Interstate, and no more troubles. I wish it would go ahead and puke itself so I can know it's fixed.

Yep, had the front vac elbow go out last fall, replaced both ends.
 
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