[MoeB]

On a recent trip, my truck started intermittently making a stuttering or scrubbing-type sound. I noticed it mostly on hard accelleration but also a few times on decelleration. The engine would make sort of a rapid "zhuh-zhuh-zhuh-zhuh" sound, three or four per second. The sound was accompanied by slight loss of power, and black smoke puffed out the exhaust in synch with the sound. I thought I heard the same sound about 2k miles ago, but loss of power was much more pronounced at that time, and the dealer diagnosed it as a stuck EGR, which they replaced under warranty because they said it had a bent piston (!).

Truck has 25,000 miles on it. Does this sound like a turbo issue? Or something else? I'm wondering if the vanes could be all carboned up, since the EGR valve was. Maybe some sensor somewhere is causing the vanes to flutter erratically under boost?? Could this new EGR valve be stuck after just 2k???

 

[MoeB]

No opinions?

 

[FamilyRide]

[ QUOTE ]
No opinions?

[/ QUOTE ]

I'm sure there are, but it's so common and so many threads, it's probably just passed over. You pretty much nailed possibilities so thee's not really much more to say. Well not much more to say that would be of much value that is. /ubbthreads/images/graemlins/wink.gif

 

[MoeB]

Oh. /ubbthreads/images/graemlins/blush.gif I tried searches but didn't really find any threads that were a good fit for the symptoms I'm seeing. Maybe "zhuh-zhuh-zhuh" isn't the best keyword to search with. /ubbthreads/images/graemlins/grin.gif I'll take it in for diagnosis when I get time. Meanwhile I'll keep poking around here, I guess.

 

[DecreasingDave]

I had this on my work truck ('04 Excursion), I had the dealer fix it and I believe the replaced the EGR.

Dave

 

[dosdedojack]

Try searching 'turbo fart' to see what you find. I'll go with the EGR also and maybe add the MAF sensor.
Good luck.

 

[RStafford]

Sounds like the same thing that happened to me, mostly at highway speeds. They did a road test with their laptop and found some injectors dropping out.

 

[MoeB]

Thanks guys. I did read a bunch of turbo fart/flutter threads but most of the symptoms described didn't seem to match mine. The loss of power/smoke matches, but the sound descriptions seemed different. A few came close, though.

It does make sense it might be the EGR again, since that's what it was last time I heard this sound. If it is the EGR again, it will be the third one, and this one only has 2500 miles on it. Must be some other problem that's causing it to get gummed up so fast. Tech told me to drive harder but my right foot can't go any farther than the floor. Wonder if a bad MAF can make the EGR gum up quicker.

The thing that makes me suspicious of the turbo is because when they replaced the last EGR, I asked the tech if he tested the turbo for sticking vanes. He did and said "it stuck once briefly" but he couldn't recreate it after that. Seems like once is enough to indicate a problem, no?

RStafford, does my description of the sound match what your truck did? Made a loud stuttering sound. I'll ask the tech to do the road test injector diagnostics when I take it in.

 

[BB_TX]

My '04 F250 had something similar, except it sounded more like a cough and only happened when towing and then only when pulling a hill. Started at about 35,000 miles. It would "cough" about once per second and blow smoke until I let off the throttle. Ran fine on level road. It was the EGR valve. Dealer replaced the EGR valve and it ran fine after that. Traded it at 53,000+ miles with no further problems.