F150 has the 5.4L w/ the auto. 59K on the ticker. This "spuddering" type problem only happens when in overdrive. Mostly highway and when starting to pull up small hills. The symptom is a slight jerking and "spuddering" feeling. It goes away with more rpm's and some acceleration. I've tried injector cleaners and 91 octane just for grins, nothing helps. Is this a possible COP issue? Any ideas?

 

Have the spark plugs ever been replaced?
Does the check engine light ever come on?

 

cop, plugs,fuel filter

 

My truck does the same thing. If you find the fix please let me know.

 

Plugs are still original and havent really checked the fuel filter yet. Searching is starting me to believe that it's a COP. I'm going to try and get the codes pulled and see if it's coming up a a mis-fire on one of the cylinders. Can they tell me that at auto zone w/ their code readers?

The check engine light has not been on yet.

 

If you've had a mis-fire, it should show on the codes. "Many" auto places will pull codes no charge. But if you haven't had a CEL, don't be surprised if there are no codes.

At almost 60k, I'd be replacing fuel filter and air filter for sure. Give the MAF a quick cleaning.

 

Unless the misfire has been frequent enough to cause a CEL, the drones at AutoZone won't be able to pull a code.

You can help them by duplicating the misfire long enough to set the CEL.

Just find a nice long hill and drive up it. Use the gas pedal to maximize the misfire while not downshifiting out of overdrive. A couple of times might be enough to induce the CEL to come on, setting a code, and giving you a necessary clue as to the source of the misfire.

If you can't get the CEL to come on and don't have access to a scanner that can run the Cylinder Balance Test (CBT), you're pretty much stuck with either disabling a cylinder at a time until you find the dead one or else shotgunning the thing.

Steve

 

all the above are good to try and if they dont' work then take note of if the truck is shifting in and out of od lock up when the shudder happens. ive seen that the torque converter starting to go can show up going into od lock up first. hows the tranie fluid level? hopefully this isn't the problem.

 

What was the outcome of this? Same thing just started happening on my truck. I don't understand why it would stop happening at higher RPM's. I would think it would be worse then.

 

check out the thread "Truck Jerking/Shuttering around 45-50 mph"

 

When I do a search for that I end up right back here.

 

This issue and explanation has been answered dozens of times.
The misfire only in OD is a result of a 'specific set of conditions' that exist in OD.
The basic problem is one cylinder with a faulty coil.
Since the misfire comes and goes it is not considered a hard fault to set a code because each time the PCM cancels the dynamic record when the misfire goes away.
It can be found by two methods.
1. Use a Scanner with trap capability to freeze the info when it happens.
2. Use the Scanner to look at mode 6, test 53 at all the misfire monitors for one with a high count out of limits.
Auto stores likely won't go that far not knowing about how to do such diagnostics on a Ford.
The explanation for the fault is usually not fully appreciated unless a student of how the system works.
Good luck.

 

Ok. I printed that & will show it to my tech. Thanks.

 

Hello, I have a 97 f150 with the 4.6 and at 35mph, 3000 rpm, it will "buck" even If I hold it to the floor.... It won't go any faster.... I changed the shift solenoid with no change... I'm at a loss, if anyone can help me, I highly appreciate it!

 

Nyper, you don't have the same issue as above.
You don't have the same coil system on 97 4.6.
Why would you change anything until you prove what the trouble is?
What does a shift solenoid have to do with the engine rpm?
Which shift solenoid did you change?
A Scanner is needed to take a look at live data.
Testing is in order to locate anything out of spec and limits.

You can not second guess these systems and expect to get lucky.
Good luck.