Not sure whats causing this... with video

[Billyisgr8]

I posted below a video in my other post, but to get more people looking at this video I posted a new thread.

http://www.youtube.com/watch?v=-Av6Nu2feXk

Pretty much at 1800 rpm the motor goes absolutely smooth running, anything below this point the motor is making this rattling noise and terrible vibration. Injectors are all good, oil pressure is 20 psi at idle, and 50 at 2800 rpm when the engine is hot. I have checked so many things can't realy say what is happening.
Maybe a plugged oil galley that only lets oil pressure through when above x amount of pressure??
Injector pump that isn't flowing properly at low rpm, and flows good above x amount of flow. Cracked injectors though and all cylinders make the engine rough running the same, so I think I can rule out the injector pump.

Any other idea's

 

[87crewdually]

Is the injection pump timed correctly? Atleast is the static timing marks lined up or close to each other (the scribe marks on the nose of the pump and on the mount)? I'd fill a new fuel filter with diesel kleen, start it for 10 seconds and shut it off and let it soak for a while then try it again to see if it cleared up.

 

[Billyisgr8]

Injection pump was timed when put on by the diesel place at 10.5 degrees 22,000 kms ago , timing mark is abit before the cast in mark on the housing which is still in the same place. This noise started at about 4 hours into my 5 hour trip, it was not this bad, it has progressed to where it is now. It started as a drone sound only with vibration, now it runs with a vibration, and the drone which is quite loud.

 

[Ataylor]

Hmmm, Do you have a diesel compression test kit? It could tell you if everything is kosher in the valve train, but still I'm at a loss.

 

[Goofyexponent]

I am wondering if there is somethign in the pump that isn't timing right. She has a nasty PSD rattle below 1800RPM....as if the timing is advanced too much.

I would mark the case with a punch, then roll the timing back until the marks line up dead on and try that. If it don't work, then just roll the timing ahead where it was and start back to the drawing board.

 

[Billyisgr8]

Ran diesel clean through the pump and it didn't do anything except idle higher once I went back to start it. Then I retarded the injection pump as far as I could, and it quieted the engine considerably, but the same rattling is there just quieter. The drone is easier to hear with the engine rattling quieter, The tone of the drone to me sounds as if it is a dry bearing, but once the engine smooths out I hear no more drone. Darn, and I didn't save any of the oil from my oilchange to send in for a sample, its all mixed in the mixing barrell for fuel now.

I did notice when it was on the cold start-up cycle and idleing higher, the rattling stopped at 1500 rpm instead of 1800 rpm. Is this a clue?

 

[Goofyexponent]

Ran diesel clean through the pump and it didn't do anything except idle higher once I went back to start it. Then I retarded the injection pump as far as I could, and it quieted the engine considerably, but the same rattling is there just quieter. The drone is easier to hear with the engine rattling quieter, The tone of the drone to me sounds as if it is a dry bearing, but once the engine smooths out I hear no more drone. Darn, and I didn't save any of the oil from my oilchange to send in for a sample, its all mixed in the mixing barrell for fuel now.

I did notice when it was on the cold start-up cycle and idleing higher, the rattling stopped at 1500 rpm instead of 1800 rpm. Is this a clue?

when you say that you retarted the timing as far as you could, where did this put your static timing marks...in line with each other, or back past each other?

 

[paulzx]

I had a similar issue with mine, the noise was very very loud, i notice it when I had passenger in the truck and had to talk very loudly at them just to carry a conversation.. i thought it was a fuel issue at first, cause the noise would go away in certain condition. I had put a different pump in that week, thought that was my issue timing or somthing along those lines. It ended up being a a crack flexed plate (auto tranny) just remove the cover on the tranny and inspect very very closely. it was very hard to see, but if you start up and listen underneath with the cover off, you'll hear it. if you are running a standard, well i don't know then. just a thought. something that i've experience.

 

[fury9]

maybe something with one or more of the exhaust valves. Do you notice a loss of power or anything else out of the ordinary?

 

[MR.T]

On the driver's side of the IP there is a roller on a face-cam that operates an advance piston based on throttle position. Just had a thought that it might be worth looking at -- Rotate the throttle and check that the pivots and roller all still there and working, and that nothing is loose.

 

[Billyisgr8]

The static timing marks were practicly lined up when I retarded the pump , It was timed about 1/8" beside the line advanced before I loosened it, the bolts wern't terribly tight too. Just so I got the direction correct, Advanced from the 10 o'clock line would have the line closer to 11 o'clock and retarded would have the line at 9 o'clock looking at the pump from the drivers seat?? If this is not the case then my pump has moved retarded, and I need to get a bigger wrench to rotate the pump more.

I was under the truck and pulled the inspection plate to see if my torque converter was loose it wasn't, but I did not inspect the flex plate though.

Is it possible the pump advance is stuck ono?

Loss of power only when the rattle is happening, when the rattle stops, power is strong as it was before.

Now after letting the truck sit for awhile more, rattling stops and smoothes out at 1100 rpm, so the only thing I have changed is the timing which only quieted the sound, rattling still there, but the rpm at which the rattling stops has come down 700 rpm. So It must be something in the injector pump which has been loosened from the diesel Kleen.

The advance lever is working good

Thanks for all the ideas.

 

[TWeatherford]

My brain is fried from sun and heat today, so I'm not sure if I'm interpreting your description of advanced vs. retarted. In order to advance the pump, the top of it should be rotated towards the passenger side fender. Rotating the top of the pump towards the drivers side retards it. I figure it makes sense, only a retard like me (the driver) would drive this truck so pointing it towards me makes it more retarted. Like I said, the sun was rough today.

 

[Billyisgr8]

Oh good I have also interpreted it right then. Your description is easier to understand then the oclock way.

 

[Billyisgr8]

Diesel mechanic neighbour came over and also thought it was the injector pump timing causing all the noise. Took in the pump, and it had a stuck advance piston, and 4 injectors were leaking fluid like a tap, not bad for only 21000 kms on it....NOT!... Replaced these today, and now the noise is very loud, and it stops at 800 rpm, . I am at a loss as to what is causing this. My engine has 460,000 kms on it. What happens when cam bearings become worn? Does the crankshaft timing gear ever come loose?

 

[zrexryder]

Had the same sound,torque converter came loose, broke off 2 studs and jacked up the flex plate. fixed it last weekend.