04 6.0L bucking when in overdrive
 

I am new to the forum and new to diesel engines. My problem is that when I am getting up to speed everything is smooth until I reach about 45mph and the transmission shifts into overdrive the engine starts bucking or feels like it's cutting out. When I accelerate it gets smooth again. It seems to buck when running 45 - 60 mph in overdrive no matter the conditions.

Doesn't matter if motor is warm or cold.

Not pulling anything.

Tested FICM, all is 48.5v
cleaned EGR Valve

Truck has no engine mods, have 6in. suspension lift

Does your speedometer bounce around when this happens? If so it will sometimes be the Speed sensor which is located on the rear axle housing. Take it out and clean it off. It is magnetic and the tiny metal shavings will interfer with it.
I had a similar problem with my truck doing as you explained. But my speedometer also was mesed up. Replaced the speedsensor since it was bad. Also if your truck has ever had the cab off for any repair. There is clip connections at the fuse box on driverside fenderwall. I had 2 clips come loose. Found this out the hard way after speedometer and tach quit and truck was doing the bucking.

Another thing it could be is your egr valve is clogged. You can clean it off and reinstall but use new Orings on it. If none of the above the vanes in the turbo could be stuck or the turbo needs cleaned.

I know all of these could cause it to buck. Test everything out. clean your EGR and Speedsensor. Check the fuse box connections.

The speedometer and tach work fine. I can see a little miss on idle as well. Cleaned egr today but no change. Don't know if cab has been off. I'll try to clean turbo. One thing I noticed was the piece on front of air filter missing, wonder if that can cause problem. Also, while cleaning EGR valve, I noticed the lower o ring was messed up a little. Didn't have any replacements so put it back like it was. Will fix that soon.

The slightest crack on those Orings will mess that EGR up. I cleaned mine one time and didnt replace the orings. Didnt fix nothing till I got new ones on. As for the Airfilter missing something. Is it the air filter itself or to the case? I know there is a mod you can do to the case which will supply more air to the filter.

I can see the front paper honey comb of the air filter all the time.

Sticking injectors.

How often do you change oil? Why type of oil do you use? What oil filter do you use?

Buy some Rev-X oil additive, I'd almost guarantee your issues disappear.

I just got the truck and haven't changed oil just yet. Will do that soon. haven't decided what oil and filter to put in yet. I just find it wierd that injector would stick everytime i get into overdrive going 45-60mph. The truck just shakes and jerks until i accelerate, it downshifts and the shaking goes away until it shifts back into OD. I guess i don't really understand how the injectors really work. Is it possible that truck had a tuner on it before I bought it and the computer needs reset? who knows. I'll change oil and O rings on egr valve and see what happens. just seems electrical or fuel issue.

As far as resetting the comp goes...disconnect the batteries for a little and then re hook. Not sure this is going to make a difference though. Are you having any issues with cold starts/hot starts? The injectors on these trucks have high pressure oil pressing on the top side and thats what causes them to fire. hence the reason Mdub mentioned oil change/fuel filter change. Drain water separator? Bucking when the FICM is working correctly really points to sticking injectors and 6 or 7 cylinders firing at full bore when you press the go pedal might make it harder to feel a low fuel atomization/no fuel situation.

ive had a problem similar with it bucking when im just barely on the gas at like 50 mph had oil changed a few times and some fuel additive and havent seen the problem since. good luck and delete the egr! does the battery reset take off the programmer?

starts up fine cold/hot doesn't matter. I will change oil and fuel filter tomorrow if possible and drain water separator. This really might be issue as I noticed oil was low when i first bought it, 1/2 gallon low, filled up and no change. Hopefully not failing injector.

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also, any reccomendations on oil and filter to use, starting to get cold here in Missouri.

Based on the whole cold issue im running 10w30 Rotella T. (Make sure its an API cert oil if you dont go with Rotella) year round...as a plus its super cheap at walmart. like 16 bucks a gallon. as far as oil and fuel filters go myself and many other will highly recommend you only use motorcraft oil and fuel filters or the suitable alternates through an International dealership under the brand name Racor. The part numbers are around here somewhere...prolly in one of the stickys

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oh yeah...what Mdub said....REV-X. Completely cured my injector stiction issues. kinda pricey but well worth the added life of injectors.

It's sticking injectors, quite common. It does it when the truck shifts to overdrive because it's a higher load situation at low RPM. There are over 75 moving parts on a powerstroke injector... there are VERY few people who understand how they work.

I have been having the same problem ever since I got my head gaskets done again. Checked the plugs at the fender and they are all connected. Guess I'll invest in some of that Rev-X too and see what happens.:humm:

Did you ever find out what it was that made your truck buck just after it shifted into overdrive. I am having the exact same problem between 50-60mph with a good FICM and clean EGR valve. Engine runs good in other gears at same RPM.:argh:Thanks

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[QUOTE=lemming202;824094]I am new to the forum and new to diesel engines. My problem is that when I am getting up to speed everything is smooth until I reach about 45mph and the transmission shifts into overdrive the engine starts bucking or feels like it's cutting out. When I accelerate it gets smooth again. It seems to buck when running 45 - 60 mph in overdrive no matter the conditions.

Doesn't matter if motor is warm or cold.

Not pulling anything.

Tested FICM, all is 48.5v
cleaned EGR Valve

Was it a sticking injector or something else? Love to know, so I can fix mine!!! :dang: Thanks

I have an 04 6.0 powerstroke and the same exact problem. Bucks when in overdrive doesnt matter the speed. I spoke with a buddy of mine and he works for ford and he talked to the diesel mechanic over there, he said it sounds like the tranny...? The thing with mine is that it only does it when my truck is just getting warmed up. It starts bucking really bad when i pedal down but then stops when it down shifts, I let off the gas and it shifts back into overdrive and starts again. Once my truck is warmed up it goes away. Any replies would be greatly appreciated..

Definitely sticky injectors.

FWIW, most of Ford's diesel tech's I've met, really don't know squat about diesels.

Try some Rev-X, I bet it goes away...

You may also want to try the FICM test at the top of the 6.0 page too, just for peace of mind.

Where can i buy some Rev-x. I have heard about the stuff before but never asked about it.

We just came back from a 2500 mile trip. Half way was with a 8000lbs 5th wheel. The tranny held out fine and nothing changed other then it got a little better in overdrive. My scan says #2 cylinder but it is a new injector. Maybe the oil line to the injector is leaking? I noticed on the return trip that it sounds like my fuel pump in the tank is making intermittent noise - next check will be the fuel pressure. Also I am interested if it could be the opposite cylinder to #2 acting up. Possibly some kind of leak on that injector and pre-ignition. Tranny scan says nothing wrong with it plus on the last leg of the trip we ran it at 70mph with the trailer. The interesting thing is that the engine peers along just fine but the hesitation is still there. 15miles per gallon-truck alone and 12miles per gallon with the trailer at 60-65mph:humm:

RV cruiser, that injector could be slightly loose, or a bad o-ring on it or something simple like that. If it says #2, it's #2, it wouldn't be a different injector.

HOX, shoot a PM to sunsetsky on here. Or wait for them to post here...

Thanks Mdub707,
I'll check the oil rails when I get a chance. Just got a snow dump again. Oops, my spelling wasn't to good in my last post.

Did you do the injector yourself? They have been known to loosen back up when using Ford's recommended torque values. Most guys go a little past that.

If it was the injectors, wouldn't it do it in every gear not only in overdrive.

If it was sticky injectors wouldnt it do it in every gear??? Not just in overdrive?

No. OD is low RPM high load, it's where it shines. Injection pressure is low due to low RPM's and low throttle input. It's sticky injectors man, it happens all the time.

Ok thanks, is online the only place to get rev-x. I called around but could not find any.

You can get it right here, PM sunsetsky...

Diesel Bombers - View Profile: sunsetsky

:c:

Haven't heard anything back from him yet.

Mine did the same had 2 injectors bad then I cleaned the turbo and has ran great since

finally got around to changing the oil. Used rotella t 15w 40 and I just put in rev x. I have to say, that rev x is amazing stuff. I drove 11 miles and the bucking went away. I still need to get new o rings for my egr valve and maybe need turbo cleaned but just oil change and rev x made a huge difference. Rev X is high dollar stuff but dang it's good.

I also have the same issue with my 93 6.0, bucks in overdrive mostly while it's still warming up. About a week after this started my turbo crapped out coming up a hill. Turns out it was the actuator valve, my mechanic put a used one in for me free of charge and that solved my turbo problem. That was a few weeks ago and I hadn't even noticed till two days ago but after the turbo incident the bucking stopped. But two days ago I was hauling about 10k lbs up a hill. I was taking it easy, not being too hard on it. The turbo was giving me satiate adequate power, but kept spurting air back into my intake, it never did that before. It also squealed a bit towards the top of the hill. I got scared and backed way off the throttle. Now yesterday, with no load, the turbo was spurting again on a hill, and I noticed the bucking started again and is slightly worse, and twice it seemed to not want to shift from 2 to 3 till I left off the throttle a bit. I have yet to do my EGR delete, and I'm wondering if this is all related to that... I have to haul about 20k lbs of hay either today or tomorrow...I'm nervous to see what happens.:argh:

Sounds like your turbo needs to be yanked and cleaned...

DTS Articles - Turbocharger Reconditioning

Try that...

The bucking is probably separate from the turbo issue.

04 ford bucking in overdrive
 

I have the same bucking on my 2004 6.0 when it shifts into overdrive at 40-50 mph however I also experience a stuttering when engaging the cruise at this speed. All performs once engine has warmed up some. I plan to change oil on engine and trnny and check the speed sensor for fault. ANY OTHER IDEAS? Please advise.

Probably a sticky injector. What oil and oil filter are you using? A couple bottles of rev-x would probably help you tremendously.

Electrical Bucking
 

Check the battery cables. Had this problem because of a worn out positive cable bridge. Replaced and all is fine.

Interesting, how did you end up chasing that one down?

battery cables
 

I have a Bully Dog. Updates made it twitchy. Restored to earlier version, but still had intermittent problem with bucking. Did EGR and injector service with BG. Still problem. My mechanic noticed the bad battery cable and burn through the rubber protector, indicating short. Everything on these trucks depends on electrical power. I even replaced bad FICM a year ago...everything indicating an electrical problem. Battery cables are a $300 change that can avert thousands.

Mine was doing same thing switched to rotella t6 rev x oil additive and rev x distance fuel treatment and its like a whole new truck

Thanks .. will try the revx etc and have a kit for replacing the egr. will advise. Have discovered that if allowed to get quite warmed up then it doesn't miss. Indicates to me a oil pressure on injectors question.

So basically just happened to notice it and replaced it. Gotcha. I rebuild FICM's on the side, I know all about the electrical power needed to run these things, it's crazy even weak batteries will make them run like crap and shift terrible.

Usually when it misses cold and then warms up and runs fine, it's sticky injectors. Start with the Rev-x oil additive, I bet most of the issues clear right up.

So mdub what are your thoughts on a ficm with the atlas 40 i was thinking of ordering one?