2000 Ford F350 SD, Dually, Dump Stake body, 4X4 extended cab. Triton V-10. 63,500 miles. I've had it for a month or so now.

As some of you may remember I asked some questions a while back about a vibration in this truck. After bringing it to a local dealer and having a new driveshaft installed, and $1,500 in total work later, it was better but still had a vaibration. After reading some other threads on the board here I was sure it was ball joints. I don't drive the truck much as it is used on an as needed basis, so time between figuring something out, getting it to a shop and fixed and back takes me some time.

As circumstances would have it I blow a tire last week and brought it to Sears to put new ones on. While there I asked if they could take a quick look at the front end to see if everything was in good shape. Realizing it was Sears I didn't put a lot of faith in it but it was there so ....anyway, they found a bad ball joint which I had them replace. This took care of almost all of the remaining vibration and actually on the trip home it ran just as smooth as a new truck. It took care of a banging I had under the truck at the same time. I was a happy camper.

However, I took it out yesterday and and it has a vibration again, but different. It comes and goes. From what I can tell it is coming from the engine skipping or running rough. The reason I assume this is because when the engine is running good it doesn't vibrate at all. When I feel the engine running rough it is vibrating again. Now, I had the wires and boots replaced at the delearship on the first repair. It was running very bad when it rained. Now it runs like that but not as bad and moisture makes no difference.

Will a general tune up eliminate this problem or what else should I look for? Other than the vibration the only other thing I find wrong is when the engine is running rough it cuts in and out. Not to the point of stalling or anything but I have to give it a hair more gas then let off back and fourth until it clears up. You can just kind of feel the engine back and fourth in the pedal. I know thats not a good explaination of the problem but thats the best I can describe it.

Thank for the help, sorry for the book but I thought I would eliminate a few areas I know not to be the problem.
SM

 

Have you had the spark plugs replaced? Check for a vacuum leak at one of the hoses, including the PCV line, or a loose clamp on the air intake tube. A scan for codes in the ECM might help. If your lucky there may be a hard code or a pending code stored in the computer. Try to take notice if the vibration is there when the torque converter isn't locked up. You might be getting TC shutter.

 

Sounds like it could also be a coil pack. I thought the trans was acting up on my 99, turned out it was a mis-firing coil pack. Strange, it wouldn't do it under load, only when you were coasting, you feel something like a stutter.

 

The spark plugs where changed at the same time as the wires and boots. I'll check the other items you mentioned. I'll have to get it into a garage for the computer stuff though.

Thanks

 

Sometimes it get hard to tell if it's transmission or engine. He indicated the wires were replaced. I thought it would have COPs, but wasn't sure. If it is a COP it will eventually store a code.

 

A stutter would better describe the vibration. Except this one does it under load. If I let off it stops doing it. At first when I turned the wheels left or right it would stop but then I realized I was letting off the gas when doing that.

 

There are no wires on that engine just COP"s coil on plug little units. They go bad you need to find out which one. Some guy's buy a new one and start changing them out one at a time till they find it. Or take it to the dealer.


Dick

 

OK, so that I understand. The COPS are not the boots I had replaced? I thought the invoice said wires, boots and plugs but I was didn't really read it closely. If I remember correctly I had to have one of those replaced on a Motor Home I had a fews years ago. They are quite expensive, right? That was under warrantee at the time. This looks likes it's on me. Will the computer show which one is bad if that is the problem?

 

Is it speed sensitive or will it vibrate anytime you apply power? Since you had it to a dealer initially I'm going to assume you have a two piece driveshaft and it has been shimmed as per TSB.

 

From the little I have driven it, it does it under power. The dealer did put the driveshaft in and yes, two piece. Whether or not they shimmed it??????? Good question. With my albeit limited knowledge, I would rule out the driveshaft because it only does it when the engine is running rough. It does not run rough all the time. Just most of it. When I took it back from Sears after the tires/ball joints install it ran like a champ.

 

COPs have a replaceable boot that is known to go bad. Yes, the coils are expensive and a common problem. I would hope the dealer didn't install a complete set just to try and correct a possible miss.

 

The dealer just replaced the boots and plugs apparently. The bill for that was 145 so I assume it wasn't the COPS. I am reluctant to bring it back to the dealership at this point. Is the dealer the only one capable of diagnosing an issue like this? Or do other shops have the proper set-ups to read the codes?

 

Any shop with an OBD II scanner can check for codes. The better the scanner the more it will do and of course the tech's ability becomes a factor. It has been my experience normally Fords don't set a misfire code unless it occurs at idle. If it is a COP going bad it will eventally misfire at idle and set a code. An alternative is to buy one or two new coils, OEM only, and rotate them through the engine until the roughness goes away. That is assuming a COP is what is causing the vibration.

 

That might be the way to go. Any idea on what they cost? And a diagram would help. ;-)

I have some mechanical ability but have zero Ford experience.

 

I think they list for about $60.00 and discount for about $43.00. If you decide to diy, the electrical connector has a tab on the underside you press to release the connector. Easy to swap out and only takes a few minutes.