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
Sounds like a turbo
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!!!
Still sounds like the turbo to me
Quote from: Geom on November 16, 2016, 12:53:19 PM
Then after shutting it off, it takes a second or so for full silence.
With this comment I'm considering parts still moving
Floyd
Listen to Clifford. Bus Yoda is seldom wrong. And FWIW I concur with his diagnosis.
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
Sure easy enough to find out,, just pull the intake side piping and spin (or try) the turbine..>>>Dan
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
WAS THE TURBO PRELUBED...
how long ago...
your old turbo...
or a new/rebuilt ?
pulled the intake and loook yet ? ...
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
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... :P
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
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
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
Broken crankshaft
--Geoff
Quote from: Geoff on November 17, 2016, 05:48:07 AMBroken crankshaft?
--Geoff
I hadn't thought of that, but I've seen some crankshafts that break very cleanly so the the break is sort of like a "slip joint" -- they kind of hold together until they're under stress or load and then the broken parts move against each other. Of course, there are other failure modes of broken crankshafts, too. It would be a major failure if that's the problem, but it does sound like a possibility. :(
There is a hub with a key that drives the fan maybe they forgot or the key sheared I hope the crank didn't break George has had quite a trip,I hoping it is something in the direct drive fan assembly ??? what's another weekend Farmington NM after 3 months
I noticed they wrapped your pipes. GREAT stuff for keeping temp in check, but is it possible one of the stainless steel straps is loose, or didn't get cut off and is hitting something?
Sound continues for a second or two after shutting off engine........ eliminates most conjecture here. Turbo is most likely as they spin after engines are shut down for a few seconds.
Quote from: chessie4905 on November 17, 2016, 07:33:43 AMSound continues for a second or two after shutting off engine........ eliminates most conjecture here. Turbo is most likely as they spin after engines are shut down for a few seconds.
This has been something that I have been thinking about too. But now that you've said this, I realized that I'm not sure if he meant "continues after the engine has been switched off but before engine rotation has completely stopped" or "engine shut down and come to a complete stop and the noise continues after all rotation has ceased". Chessie, I think you're right, it's almost certainly the turbo, with a slight possibility of some other rotating part that's come loose and continues to spin when it should be stopped. But working on the principle "the simplest answer is most likely to be correct", that points towards turbo. But part of chasing problems is eliminating all the little not-likely issues.
It will be interesting to see what's found when an experienced tech gets into it with a well-planned trouble-shooting plan.
Well.... considering the fact that he's been stuck in Farmington for 3 freakin' months it's sort of a tip off that "Experienced tech" isn't an option.
I agree that the turbo is most likely, going off the list of symptoms, and since it's real quick to check, it should have already been checked by the tech that came out.
This ordeal just makes you want to go sigh.......
Jeff
You can put your hand on a turbo with the engine running and tell if it is vibrating from a failed part on the compressor or turbine wheel
It has such a tinny, rattling sound, I still say it is a baffle in the muffler that has come loose and blocks the exhaust causing the black smoke. First remove the intake on the turbo and wiggle the turbine, then can use a piece of wood to keep it from spinning and start the engine to see if it is coming from the turbo. I would say to disconnect the exhaust side from the turbo to bypass the muffler, but then it would be so loud you couldn't hear anything above the exhaust note. Good Luck, TomC
plus one on somewhat tinny sound, I was there and then started listening to other videos where focus was other places around the motor also, ?.
With these I'm trying to get my thoughts on a coupling with some lite metal adjacent that will continue to spin.
what has me is the mention of a bit of black smoke but not a real feel in power loss, actually a let off at first, understandably but just that part says not much power loss in that moment respectfully.
I am sorry for sure, and my armchair sometimes is out there, goodluck.
Floyd
I was going to say the dampener behind the crankshaft pulleys has come apart, but on further analysis, I think Geoff is correct. Your crankshaft is broken.
After looking at it again, I think that's the camshaft pulley, and I think the pulley assembly has come apart inside. Maybe they forgot to bolt it onto the shaft.
You can see it flopping around in the first video and the pulleys are unbalanced and not turning at appropriate engine speed.
Just my two cents but if the crank had broken and was in fact slipping wouldn't it throw the firing order out of order and cause more severe issues or does this not pertain to a two stroke. To me a broken crank would cause more than a clanking sound more like a catastrophic failure to the power train.
Quote from: scanzel on November 17, 2016, 11:10:16 AM
Just my two cents but if the crank had broken and was in fact slipping wouldn't it throw the firing order out of order and cause more severe issues or does this not pertain to a two stroke. To me a broken crank would cause more than a clanking sound more like a catastrophic failure to the power train.
No it could break on the step down past the oil pump and it would still run and have oil pressure
Why would it still run if engine was turned off. With new cylinders and rings it should stop quick. The other thought is that something was forgotten to be tightened, but still sounds like the turbo, especially in that short of a trip.
Watch his first video in slow motion. At 0:04 you can see the pulley wobbling and something behind it is flopping.
I think they just forgot to tighten the bolts on the crank pulley and they fell out. It's now slipping on the shaft.
Clifford, my friend, you are, without any doubt, truly a bus Yoda!
The two shops talked this morning and decided to disassemble the fan drive and take a look.
They took it apart and didn't seem to find anything.
But after looking at the turbo, it does indeed appear to be that. Or at least the turbo is certainly one of the problems we're seeing. The exhaust side of the turbo was essentially just free-spinning and loose. It doesn't appear that there's any shrapnel and the turbo blades (exhaust side anyway) appear intact. This is from just a cursory exam as they haven't fully disassembled that yet.
I also have no idea if the intake side could've done something to the engine. Here's to hoping for not!
Before shipping it, the engine shop had mentioned "not liking something" about the turbo when they were dynoing it, and said they'd ordered another one.
But that could explain the entire chain of events. Smoke, seeming loss of power, etc. it all happened so quickly and so close to one another, and of course on a hill.
The sound was also very deceptive, because it was definitely coming from the lower left side of the engine.
We've contacted the engine shop to source a new turbo, which will be interesting the week before/of Thanksgiving.
Anyway, that's the update. More to come later...
Make American buy you a new turbo 2 turbos something is wrong in their rebuilding process.If you see any damage to the compressor (the cold side) like blades chipped or broken tell them to pull the blower and replace the after cooler and blower
good luck my friend
Quote from: Geom on November 17, 2016, 12:04:34 PMClifford, my friend, you are, without any doubt, truly a bus Yoda! ...
But after looking at the turbo, it does indeed appear to be that. ...
Anyway, that's the update. More to come later...
There's something in my mind, too. Since Craig mentioned it, I went back and looked at 0.04 on the first video again. It's really hard to tell on a video the loudness, type, source of a sound but it sure seems to me that there's something flaky about that pulley/dampener.
It looks for sure that you're in for a turbo change (ditto Clifford's advice to be sure that there's not something killing those turbos), but I'd sure check that pulley/dampener very closely. One of my most costly lessons was learning the folly of just assuming that you only have *one* problem at the time.
I hope it is only the turbo, George (and I'm sorry that you've got that) but I want this repair to be the END of your problems.
The balance pulley on the camshaft looks good to me what you are seeing is the gap in the pulley those are not solid on the backside
It is frustrating trying to figure out what is going on with a few video clips. If I was there I could trouble shoot what the problem is in a few minutes. It could even be the blower lobes hitting each other.
They don't keep moving with engine shut off.
Quote from: chessie4905 on November 17, 2016, 05:36:31 PM
They don't keep moving with engine shut off.
When the engine shuts down, it is still is moving, and even rotates backwards against compression.
QuoteBut after looking at the turbo, it does indeed appear to be that. Or at least the turbo is certainly one of the problems we're seeing. The exhaust side of the turbo was essentially just free-spinning and loose.
Can you clarify this statement?
Exhaust free spinning and loose as in the exhaust turbine will turn while you're holding the compressor turbine stationary? If that is the case the turbo is FUBAR for sure.
If the shaft isn't broken and the fins aren't torn up from contact with the housing or trash going thru then you just described a perfectly normal turbo.
Kevin
What looks like the cam pulley going wobbly is just the balancing weight behind the pulley going around
Quote from: TomC on November 17, 2016, 11:31:28 PM
What looks like the cam pulley going wobbly is just the balancing weight behind the pulley going around
Ok.
I went and looked at my 6V92 and my cam pulley doesn't stick out at all. This one looks like it's out about 2 inches from the block. In slow motion, it looked like
the pulley itself was wobbling.
It looks to be about 1/4 of a inch from the front plate that is normal for most but they do make different weights for different cams and drives
It really looks to me that this whole situation brings up some important points:
1. This has got to be the most horrible break-down situation ever in a bus conversion on the merits of expense, frustration, and duration.
2. Clifford's judgement about mechanical problems is very hard to beat. He should write a book about common problems in conversions. I would buy more than one copy, it would be the Old & New Testament of Conversion maintenance.
Quote from: DoubleEagle on November 18, 2016, 01:04:50 PM
It really looks to me that this whole situation brings up some important points:
1. This has got to be the most horrible break-down situation ever in a bus conversion on the merits of expense, frustration, and duration.
Yea it is George keeps his cool through out the saga,with me 3 months in Farmington I would have lost it 2 months ago ???,it is not going to be but a few days then the weather will start to get crappy
I am waiting for the final analysis. Somebody screwed up. Was it the rebuilder or the installer?
--Geoff
We have finally escaped the soul-sucking black-hole grasp of Farmington!!
To their credit American got a (new?) replacement turbo (from AZ) to the shop here next-day (this morning).
And to their credit, the shop here got the turbo installed in surprisingly good time.
We fired her up this morning, although it was a bit rough, with 7 or so attempts to finally get it awake. Not sure if it's normal for a new engine to take this long to start on a cold day. It got to around 25 degrees last night and it was about 45 when we tried. Engine also smoked quite a bit for about a minute or two. Kind of like the old engine used to (not quite as bad), which surprised me.
It loped for a minute or so, then was fine.
When we played with the throttle after it was warmed up, it sounded great!
There was no rattling, or banging and the smoke cleared up well.
So we prepped for take-off and away we went, just hoping to make it out of Farmington this time.
We made it to just west of Albuquerque. It was a long day and it was getting dark so we've stopped there for now.
And it got quite a work out!! Several steep ascents, descents, and all in between.
It seems to be running great now. Now sure for how long :P, but how it behaved today was exemplary.
The temps stayed locked at 170ish through all of it. It climbed all of the hills, including a really steep one on 371 out of Farmington (in first), like a goat. For the remainder of the trip, a kick down to second and we were climbing at about 45-53 on moderate climbs, and once crested third would cruise at 60ish without effort.
I'm hoping that the turbo issue was a fluke, although it doesn't fill me with great confidence that it happened 100 miles in. But I suppose if it had to happen, better at that spot than completely stranded (no where near a shop) and I was glad that the two shops were on the ball.
This process has been without a doubt a ... less than pleasant experience. But hopefully we're through the worst of it and can enjoy owning a bus again. I'm trying to put together a summary of this, if for no other reason than just digesting it mentally.
But I hadn't realized just how much I love and missed driving this thing, and today it was good to just go for a drive.
Thanks again all for the help and advice.
That is about normal for a 6v92 starting in those temps without a block heater plugged in George,American probably got a turbo from Turbo Resource in Az, Tom builds a good turbo enjoy the ride
For your sake, I hope this is truly over and you will have a great engine in your bus for the rest of your life.
When you put together your summary, please consider including the costs and $$$ spent on this ordeal. I think this lesson is one which every prospective busnut should know about before they jump into the pool. I know I'm curious.
One of the first busnuts I talked to when I was first looking for a bus said to me, "Do you have $10,000 to spend when you blow an engine in the middle of nowhere?" That was almost 20 years ago, and obviously the numbers have only increased.
Good advise Craig.
Ever since we did our first bus, we've always had a "bus fund" for that very reason.
It just gets better. 5 years and about 8 or 9 thousand miles Huggy just seams to be getting loosened up.
and a turbo engine does not start as good as a non turbo engine. less compression.
uncle ned
If my turbo engine is cold-soaked overnight at 25 and no block heater, it's lucky to start at all, and yep - it will smoke for a minute or so.
Our 4104 didn't start as well below 40° after it was turbocharged. You can get them to start when pretty cold many times by cranking them 5 to 10 seconds from the Rear while you hold the fuel shutoff closed on the governor cover, then releasing it. It helps prewarm the combustion chamber before injecting fuel.
Does anyone use ether injection? I know in general it's voodoo - especially for a 2 cycle. I have a metered charge that I can energize from the drivers seat. It has a thermostat so it cant squirt unless its cold. The metered squirt is 3 cc in our case which is a specific amount for Inline 671s. I don't use it unless absolutely necessary (severe below zero cold or inability to energize the 2000 watt block heater). It works awesome. Yea I know I'm doing an engine job on the tired old Detroit but lets face it we'd been driving a 53 bus around since 79 with a 69 motor rebuilt in 71 with ether injection all that time.
There is not enough ether in the starting fluids sold today to harm a engine most are Heptane not either, the old 100% ether capsules of the past would make one beg for mercy, I seen those blow the oil pans off before.QuickStart has a good read about ether check it out lol some of us old school guys just used alcohol when we ran out of capsules
WD40 works pretty well too. Never used it on a Detroit but I've used it a number of times on my 6.2 Suburban when I was having starting issues.
Detroit used to sell an Either starting kit .
Install the can in a special container, a button was on the dash.
Viola!
Next , the two-stroke contains the explosion for less than 1/2 the time of a 4 stroke ..
Pretty safe to use.
I know people are probably tired of hearing it but..oh well.
In the oilfield in the Arctic, I will bet 10 cases of starter in a can got sprayed into Detroit's every week and sometimes everyday. not a single one suffered as a result. thru the air cleaner or directly into the blower. Many got fed two cans.
now idling at 600rpm...that killed a bunch...
Quote from: dtcerrato on November 20, 2016, 08:26:31 AM
Does anyone use ether injection? I know in general it's voodoo - especially for a 2 cycle. I have a metered charge that I can energize from the drivers seat. It has a thermostat so it cant squirt unless its cold. The metered squirt is 3 cc in our case which is a specific amount for Inline 671s. I don't use it unless absolutely necessary (severe below zero cold or inability to energize the 2000 watt block heater). It works awesome. Yea I know I'm doing an engine job on the tired old Detroit but lets face it we'd been driving a 53 bus around since 79 with a 69 motor rebuilt in 71 with ether injection all that time.
That sounds like the Quick Start system I have in my bus. I removed the ether injector from the blower so I could install a turbo boost gauge instead, but it would be simple to reinstall it. My bus was originally from Auburn CA in the foothills of the Sierras - it can get quite cool there in the winter. A few years ago I had to start my bus after a 30-degree night at 4,000 feet, and I was surprised how much it spluttered and smoked for a minute or so until all the cylinders were firing. I guess that's normal for lower-compression turbo engines at altitude in cold weather.
John
John,
Hey that is very close to us. We are in Foresthill, twelve miles up the road. Actually, that's where George got his bus. We got caught on 395 after a good snow and tried to get it started. It must have been in the low 20s. I know he has been in much colder weather. That grinding on the starter to get it going seemed like a problem waiting to happen to us. We went with the ether start system in both our buses. One well timed push of the button is all it takes.
Don and Cary