I think your in the wrong section of the forum, diesels dont have plugs and coils.

 

Another thing to consider when having this problem is to look at ICP and IPR values on AE or a scanguage. I had this exact same problem, but then my truck finally died. Mine ended up being a HPO leak.

Dima

 

My truck would buck and the die out around 55mph so I took it in. After two different mechanics and 4 weeks in the shop I decided to bring my truck home and troubleshoot it myself. I decided to start with the basics, so i changed my oil, I noticed it was very thin and overfilled. Took it for a test drive and it ran perfect all the hesitation and bucking went away. Thank God, all I could think was that the injectors weren't getting enough pressure from the oil to fire properly.

 

Glad to hear it's resolved. Do you think it was contaminated with diesel? Or just overfilled at some point?

 

And I'm thinking that you have some leaky injectors that need there seals replaced. Read up on doing a bubble test and replacing the o-rings, that should solve your bucking as well. Making oil is bad, could lead to a run away motor and most likely will kill it if that occurs.

Read the tech section on bubble testing.

Changing the oil didn't fix the fact it was adding diesel to the oil and it will continue to do so until you find and fix the issue.

Welcome, your in the right spot! You should start a new thread so it gets more exposure.

Got a way to read the codes?

 

Even though it’s been over a year since the last post on this thread, I’m going to try to reopen it instead of starting a new one,

I have an 06 6.0 F350 dually, and a JAYCO fifth wheel. Total weight is about 22K Only when towing, I have this bucking. With, or without cruise, and nearly always on a slight up grade, although after over a year of noticing this issue, I can now trigger the condition manually with the pedal at highway speed, and maybe on level ground. It is getting worse.About 4 years ago, I had some dealerproofing done ($5000) such as, egr welded shut, reflashed, new head gaskets, n bolts, turbo cleaned n checked, new oil cooler and later the high pressure oil pump went out (another $3000!) I have added a coolant filter.

The condition occurs in OD at about 60-68 or about 2000-2150. Over that, much less often. If I turn cruise off, I can wait till the rig slows some, then accelerate and the trans downshifts normally and the bucking stops. Sometimes I can accelerate manually, without bucking, but have to be careful to feel it start. I can nearly eliminate the problem, if I’m careful and have cruise off.

Separate issues (but maybe not) are a curious cutting out of cruise at far less grade than it should, at which time it takes 5-10min of normal driving before I can restart cruise. Also, (not this trip, yet) I will get the occasional “Trailer Brake Control” fault on the dash.

When I had the HPOP replaced, they replaced two glow plugs that were out.
Only other issues in 60,000 miles of ownership, were a fault of fuel gauge and the glow plug issue. Truck has 109,000 + a little.

Does his long description ring any bells with other powerstroke fans? I’d love to fix this for less than multiple thousands of dollars expenditure! I’m sure you can understand!

David

 

You need to check for codes. See if misfires are happening.

 

What are you calling Overdrive? You have a manual or automatic tranny? The automatic has a Tow/Haul button on the shifter.