Hey guys,

Couple days ago the cab of my truck started shaking some more than usual. Its gotten worse now, however. Happens the worst around 60-80km, light on the throttle just cruising in overdrive, whole cab shakes like ****. Chop the throttle and its completely gone, any heavy on the throttle and it's gone as well. Does it loaded and unloaded. Okay at highway speeds but like i said around 70km its bad. I've got my guesses but what do you guys think it is?? Truck runs fine otherwise...

Thanks

 

You have a dead or dieing injector. These are classic syntoms.

 

I get a slight vibration under the exact conditions that you specified. Been trying to figure it out for a couple months now with no luck.

 

Okay i kind of figured this...I guess i didn't get to replacing by bad ficm fast enough?!? Also a bit misleading seeing as how i have no miss or smoke at idle...

Roasted who knows if we've got the same problem or not but this is much worse than a slight vibration...

 

I'am with unreal on this , i had a dead injector no smoke but it did run rough vibrate at idle and while driving.

 

Did you check your u-joints and carrier bearing?.

 

Last time i checked u-joints were good, checked carrier bearing and its sloppy. But would this cause the bad shaking only under slight throttle and nothing when chopped throttle?

 

Probably not like you describe. You'd think an injector would show itself all the time if you had a bad one, but unreal04's probably right if he's had this happen to him.

 

Any chance it could be injector stiction and maybe worth running some seafoam or something first before i go replacing injectors?

 

Seafoam is not going to fix it , maybe revex some say it works i have never tried it.

 

Okay i thought they were essentially the same thing hot shot secrets, rev x, seafoam ect. Either way ill try to find some, defiantly worth a shot IMO before bringing it to ford to test and then tearing into it myself...

 

I had what I know was a bad injector no smoke tried to nurse it. Truck would miss bad no load low rpm especially after shifting to OD in the 50-65 range. The truck ate the bolts, one found in the valve train one in the pickup tube. Cost me a drop the oil pan expense on top of the injectors. FYI

 

Sorry maybe i just dont understand, what bolts did your truck eat?

Can someone please explain to me the common/classic symptoms of both injector stiction and injector failure, and how their different and how they happen. Thanks

 

Stiction is typically a cold oil issue. Once your oil is up to temp, the stiction issues tend to go away. A bad injector can cause a miss but I'm not sure about "shaking".

 

I'm wondering if its the bolts that hold the injector together. I had one in our fleet truck where the bolts broke off the spool valve and dropped into the crankcase. But we just left them there. Two years later its still running.