Surging idle and rough running

[Diezel Dawg]

Well, we have a couple 6.0s at work that are our problem children. They both surge at idle and are really rough running with what seems to be a little of a loss of power. We have changed the fuel filters, air filter(which by the way is a pain the a$$) and we also drained the fuel tank and replaced it with new diesel. at first i thought the moron operator may have top it off with gasoline, that was the reason for draining the tank. But after all the work has been done, it still has a surging idle and runs a little bit better, but not much. Any ideas what this could be?? Could this be the exhaust back pressure sensor acting up??? Any help would be appreciated.

Ken

 

[Invader]

I'm not saying this is your problem, but something to give thought to.
This truck fires the injectors via a HP oil pump which then sends and electrical signal to the solenoid in the injector itself. Due to the fact that there are so many sensors and as pressures and temps change in the engine. even at idle, the injectors will fire slightly differently due to voltage variations from the sensors constantly updating the computer. The voltage will vary always and will give slight variations at idle, that you may feel through the brake pedal as pulsing idle/vibration/shudder. Mine does it. I've had it in many times to complain, but all is good, I even saw most of the diagnostic testing. All injectors were contributing the same.

 

[951_POWERSTROKE]

I to have expearenced this issue.....

If I am stoped at a light the truck seams surge a little (mabey a 100 rpm or so). It made me nervious and I thought something was wrong. I guess that makes sense as far as all the sensors/ voltage variations...etc.. Good info!

Jason

 

[Invader]

I have a refrigeration screw compressor on my boat, it is controlled by voltage input dependent on load. It will always change up an down trying to maintain the precise output parameter. Theses trucks do pretty much the same. But......... their was a concern about loping idle/idle romp, which was attributed mostly to the pilot injection procedure and has been disabled in the earlier versions of the 6.0. Oil is a huge contributing to proper engine running. Your oil is pumped into a high pressure oil pump that creates about 3000 psi of pressure to open and close the injector solenoids. So if your using an old grade/poor grade, you will experience oil aeration which won't let the HPOP pressures up high enough to fire the injectors properly....In a nut shell, don't use oil that's just "good enough"

Some good ones are
Delo 400
Rotella T
Most synthetics(check the specs)Amsoil HDD, Royal Purple, Red line.
Motorcraft
Shaeffers is also supposed to excellent, if you can find it.


These ones all have anti foam agents(aeration) and keep soot suspended in your oil longer, which is a good thing.


Jon

 

[RadialX]

Well, we have a couple 6.0s at work that are our problem children. They both surge at idle and are really rough running with what seems to be a little of a loss of power. We have changed the fuel filters, air filter(which by the way is a pain the a$$) and we also drained the fuel tank and replaced it with new diesel. at first i thought the moron operator may have top it off with gasoline, that was the reason for draining the tank. But after all the work has been done, it still has a surging idle and runs a little bit better, but not much. Any ideas what this could be?? Could this be the exhaust back pressure sensor acting up??? Any help would be appreciated.

Ken

Just wondering what years these trucks are and have they had the resent recalls done? My 04 was doing this and after the recalls its been fine ever since.

 

[rsjohnsn]

Hi all, I have transferred here from another site and plan on being here for awhile. Anyway, I had the same issue on my '04 and the dealer replaced the EBP sensor and the EGR valve and all is fine. Mine got so bad that if I didn't hold the brake firmly it would lung forward everytime the idle went up. You can also try to clean the EGR valve and see what that does or simply unplug it with the engine off and see if that helps. If the valve is clogged real bad then the later will not help. Keep us informed.

Scott

 

[davison1515]

My truck had the same problems. Got it back from the dealer yesterday, EGR valve and cooler replaced. Antifreeze was leaking into the EGR cooler. PCM, TCM, FICM all flashed.

 

[DaveBen]

How does it run now?? More or less power overall??

Dave

 

[budtoh3zo]

I would guess it is the exsust back pressure sensor i got to change mine out, Any one got anytips on it?

 

[davison1515]

Power range is the same, however, a new rumble, humming noise is coming from under the hood. Possibly the turbo, most notably between 1500 and 2000 grand. Scheduled for the new year, jan 4th is the dropoff date. I'll keep you posted. Have 29,000 on it, waiting for problem to cease, warranty to run out, and grab myself a chip