What was that noise?

[670x]

Yesterday on the highway about 2000rpm in 5th gear I hear what I can only describe as a sewing machine at full speed hitting a piece of sheet metal.
It only lasted about 3-5 seconds but scared the crap out of me. Truck seems to run fine but I'm needing to drive it a lot the next few months and am now worried about it.
The only thing I can say is it sounded like the right side of the engine and I heard it over the heater (-7f) and the radio. Injector maybe?

93 f350 w7.3 no turbo yet.

 

[Agnem]

I'd pull all the glow plugs and see if they are all intact.

 

[670x]

Oh crap your really scaring me now. I put new Beru's in last winter so I hope they are ok.

 

[sle2115]

Could it have been a rock that a tire sent into an area it shouldn't have?

Mechanical fuel pump still on it? Still in use? Just wondered about the pump arm coming off the pump. If you are still using a mechanical pump, it would have stopped pumping though...

 

[Agnem]

Rocks are usually only good for one or two clinks, and about a half a second of noise.

 

[Dsl_Dog_Treat]

Glow plugs a the easier check, hopefully one didn't break off the tip. Beru's you should be ok with.

How many miles in the injectors?
Possible one of them stuck shut by chance?

 

[670x]

Yeah some of the injectors are stock 198k miles. And the dreaded exhaust valve sticking as well as a bad dual mass (I think) cause it shakes like heck at idle and is smooth on the road.
I'm just trying to limp it till summer as I have a new (used) 140k mile engine at the house ready to go in.
definatly not a rock, was really loud and continued to knock about 50 times in about 6 seconds. Then all was fine, truck is at the mech getting mechanical pump replaced.

I'm to broke to buy new so I'm stuck with it.

 

[Agnem]

Dang! Almost 200K on a set of injectors? They should be big time whizzers by now. Probably crack open at 50psi.

 

[Dsl_Dog_Treat]

They should be big time whizzers by now. Probably crack open at 50psi.

Yeah, like the ole gravity flow updraft carbs they used to run on the Ford 8N tractors.
200 k now that's getting yer money out of a set of injectors.

 

[670x]

Yeah I had it dynamically timed last year and they said only 3 bad injectors. The rest are still painted grey.
Must be all that jet fuel I run through it.

 

[swampdigger]

Jet fuel? Do tell...

 

[670x]

I get it free (sometimes), we sump it off the trucks to test it for water then in a barell it goes. We run all the equipment off of it but sometimes there is more than we can store so I burn it. We have to pay to have it hauled off so why not use it????
I just mix a quart of oil per tank with it, no problems yet, been about 2 years now of regular use. Never have to worry about gelling up. Stuff is good to -100 or so.

 

[swampdigger]

Neat! That's Jet B or something?

 

[Russ]

I'm not a hand shaker guy, but Is it possible that was the sound of a dual mass flywheel coming apart? (Just grasping straws)