6.4 Runaway?

[6.0 p-stroke]

My dad's 6.4 has a weird issue between 1800-2000 RPM, if you let out of the throttle while accelerating at about 1800 RPM it will keep pulling hard up until about 2000-2100 RPM. Even while just cruising the RPMs hang for a second or two before dropping when you let off. It acts like it tries to runaway but then stops. I've heard about a few 6.4 runaways but I thought it was injector related, and Ford has done almost all of the work on it under warranty so I figured they would have seen the update. The truck is an 08 with 190,xxx, it has H&S tunes (he keeps it on the 250 tune), intake, exhaust, Elite studs and EGR delete and intake elbow. It also seems to smoke more than other 6.4s I've rode in, there always seems to be a slight haze no matter what. Has anyone else had similar issues? What could be causing it?

 

[Tx_Powerstroke]

Runaway is when the engine can not be controlled or shut off with out choking the air intake

 

[6.0 p-stroke]

Yes, I understand what a runaway is, I'm curious if this truck is showing symptoms of a soon to be runaway engine. I've seen a truck runaway to about 3k (5.9 cr), and luckily it came back down before it took off even higher. I've also seen a dmax runaway to 5k+ before coming apart. If anyone that has had a 6.4 runaway completely had symptoms like this before it became catastrophic I'd like to know so I can get it back in the shop before it loses an engine. It could be something in the tuning, I'm not sure, which is why I'm asking.

 

[Breaking Habits]

Does it have excessive blowby?

My good friend Dennis's F450 ran away from excessive blowby @ 42,000 miles.. Crazy chit.

 

[6.0 p-stroke]

I can't recall honestly, I don't think it had excessive blow by but I'll have to check again when I get back from Chicago.

 

[Tx_Powerstroke]

id check blowby, check intake piping also see if you have alot of oil build up, or anysort of oil that could be leaking in to give it the chance to runaway

 

[dzldoctor]

check the oil level, is it way overfull?

 

[6.0 p-stroke]

I'll check blow by and oil level when I get home. I don't think it smelled like diesel, I just checked it the other day and it seemed fine

 

[Tx_Powerstroke]

it dosent have to smell like diesel for it to cause a runaway either anything that it can burn to run it will,

 

[6.0 p-stroke]

Just changed the oil in it today. No excessive blowby and no diesel in the oil. We're about to go on a long family vacation with it on Wednesday, I'm working on getting a different tune for it. Hopefully we'll see better mileage and less smoke out of it then!

 

[patrickke]

Let me know if you need some files for that h&s

 

[Wayne]

It may be blow by, but from what you're describing I doubt it would cause all of your symptoms. Either way, a crank case vent to atmosphere is a better idea for the engine than running it into the intake. It's very good you've eliminated fuel getting into the crank case. I suspect you might have dripping nozzles, or possibly a pressure control valve on the injection pump wearing out. Need to get a good scanner on it, and watch commanded and actual rail pressure to see how that's doing. If that's good, flawed tuning could cause injectors to hang open, but unlikely. consider putting new injector nozzles on if there's no misfire. If you have a misfire, and compression is even, then you'll need a whole new injector in any dead cylinder as long as the injector circuits test good. Also check power balance to make sure nothing major is wrong, and all cylinders are functioning properly at idle. Just about every test I just mentioned is do-able with the IDS (ford scanner). good luck fixing it before she blows.

 

[tensixniner]

I had a similar issue once.
Engine would run on a bit after letting off the accelerator.
Didn't rev any higher but would take a second or two before rpm's came down.
Switching between tuners/tunes something didn't go right.
Went back to stock and reloaded tune, no more problem.

I like my KEM tunes. 250 tune or lower is $75, good deal.

 

[dstryr]

Must be your turbo seals.... I'm the professional run away expert....

Good luck getting it fixed man.

 

[OBS F350]

My truck did about the exact same thing with my KEM 210 tune, it also idled super choppy and sometimes would sit and smoke white at idle when it idled choppy, but if you revved it up it would idle fine for a few seconds/minutes then do the same thing. Also when putting it in park/neutral at random times it would rev up to 2k rpms, sometimes less and go back to idle. Smoked black haze the whole time if you were on the accelerator the slightest bit.

Switched to Gearhead tunes and have not had any problems at all since. I've ran Street, Tow, and Hot street and never had these issues show up again. By no means am I trying to down KEM tunes, I would have gotten the 345 if Gearhead didn't have such a good deal and got tremendous good reviews at the time I purchased. I may of just needed to reload the tune, but I guess we will never know now haha.

Goodluck with the diagnosis! Hopefully it will be as simple as mine ;P.