Now what? Horrible clanging engine sound

[Geom]

We were on our way, trying to get the .... out of Farmington (I'll have a more thorough summary post later).
I was on a hill. Everything looked great. Temps were good (~175-180). Pressure was good (~80).
I continued climbing the hill and noticed some black smoke. So I backed off of the throttle a bit, and the black smoke stopped. But then a few seconds later it started again. So I continued to back off.
Eventually I started hearing this terrible clanging/metal noise from the back. So I immediately pulled over.
I left it sitting in idle and went back to the engine to take a look.
You could barely hear a clanging metal sound, on the left side of the engine. Like something banging around.
So I tried to move the throttle. The engine sped up. It looked to be running OK, and no significant smoke, but the clanging noise got A LOT louder. And it would NOT stop, even in idle.

So I grabbed my camera and quickly took this video.
Then I shut it off.

I called both the engine shop and the shop here in town. The engine shop looked at the video and wasn't sure what it could be. But they said someone needed to look at it. And, of course, the shop here is the closest.
So I called the shop here. After a few minutes he said he'd send one of his trucks out to our location (we'd barely got out of town) to take a look.

I've attached a link to the video. Sorry, it's a big file. But it's only 11 seconds long. In it you can hear that clanging sound.
It seems like it's on the left side of the engine, behind the exhaust (where it's loudest) but it's hard to pinpoint exactly where.

It's not the fan, the shroud, or the fan drive cover. I checked to make sure those were clear.
The engine seems to run ok in idle but I have not attempted to throttle it any more.
The clanging noise is much louder now and fairly constant.
One thing I noticed is that after I stopped the engine, the clanging noise continued (quieter) for a second or two. Like something coming/spinning to a stop.
I can send an updated video if that'll help.

Here is the link to the video
https://drive.google.com/file/d/0B8_tLFjXVQdqVXpybkdnZEFXRVU/view?usp=drive_web

Any help is appreciated. At this point I have no idea what to do and I'm stuck between a rock and complete-insanity. But alas, we'll see what's up now!

Thanks again,
George

[luvrbus]

Sounds like a turbo

[Geom]

Interesting. It didn't sound like it was coming from up by the turbo area, but I don't really know.

I have a little more data, it seems to take it a second or two to start making the clanging sound. Then it's super loud the whole time it's running. Then after shutting it off, it takes a second or so for full silence.

Would another updated video help? Am I likely causing damage starting it again?

Thanks!!!

[luvrbus]

Still sounds like the turbo to me

[brmax]

Then after shutting it off, it takes a second or so for full silence.

With this comment I'm considering parts still moving


Floyd

[bobofthenorth]

Listen to Clifford.  Bus Yoda is seldom wrong.  And FWIW I concur with his diagnosis.

[robertglines1]

Had a exhaust side turbo wheel break the shaft and it made a hard metallic sound and there was black smoke and when wheel was in certain position it wouldn't make noise.  FWIW  bob

[Utahclaimjumper]

  Sure easy enough to find out,, just pull the intake side piping and spin (or try) the turbine..>>>Dan

[Iceni John]

And after you sort it out (I also think it sounds turbo-ish), you should consider installing a turbo boost gauge.   If the turbo is beginning to fail, the gauge will alert you that something's not right before it shrapnels into your engine.   For me, having lots of gauges is good  -  the more information I have, the better I can decide what to do and when to do it.

John

[eagle19952]

WAS THE TURBO PRELUBED...
how long ago...
your old turbo...
or a new/rebuilt ?

pulled the intake and loook yet ? ...

[TomC]

Yes easy to check turbo by pulling the intake hose off with the engine shut down. Then spin the fan and wiggle the shaft. I might also be a loose baffle in the muffler causing back pressure that would cause black smoke. But-I think turbo also. Good Luck, TomC

[Geom]

Well the fun continues.

After calling the engine shop and talking to one of their techs, it was decided that it would be best to contact the shop here to have them take a look.
I called the shop here and talked to them. They sent out their 2-stroke mechanic.
He spent a bit of time looking at it, stopping, restarting it, etc.
Everything seems fine with the engine, except for the horrible clanging noise.
It runs good and doesn't smoke, hop around, or spew anything out of any orifice; which I suppose is a good thing...
He seemed pretty certain that the sound was some sort of dampener plate by the fan drive (inside the engine) spinning loose.
It takes it a second or two to start making the sound, and a second or two to stop making the sound from engine stop.  
Sounds like something still spinning on a spool.
After some debate as to whether it would be a good idea to attempt to drive it further, the most logical conclusion was to have it towed.

So back to Farmington we went, proudly aboard the SS Tow-Truck! I think I may buy me one of those tow trucks and just haul the bus around on it . Seems like a more consistent way to get around and so far it's logged more miles in the last 3 months than the bus has. I feel like I'm in some strange movie where you're trying to escape somewhere, you barely make it to the edge of town, and bam you wake up only to repeat the same spectacular day again...  

Anyway, tomorrow the shop here and the engine shop are supposed to swap ideas and see where things lie. We'll see what happens out of that.
I've included 3 more videos of a long-ish start/run cycle and a couple of short start/stop cycles showing the sound it's making; if anyone is interested.

https://drive.google.com/file/d/0B8_tLFjXVQdqZFo2djY0V3U4cGs/view?usp=sharing

https://drive.google.com/file/d/0B8_tLFjXVQdqSnFmTi1MNXBybUk/view?usp=sharing

https://drive.google.com/file/d/0B8_tLFjXVQdqNXAyQTJ1VjBGSEE/view?usp=sharing


Thanks,
George

[stanton]

Fan clutch ?
Unhook all your belts and fire it for a minute and see if noise is  there  / gone.
Personally I seriously doubt the turbo, EZ to check ,  a look feel will be ample for diagnosis

[luvrbus]

There is a disk like a clutch disk coming off the oil pump that drives the fan it could have stripped,but it wouldn't cause the black smoke I don't think 

[Geoff]

Broken crankshaft


--Geoff