Catastrophic turbo failure.

[Shimmy1]

Ok, boys. I'm usually the one talking smart on here, but now I need some help/knowledge. 2009 CaseIH 485 Quadtrac. Iveco engine. These engines have what they call a compound turbo. It is a gear driven turbine that the exhaust goes through after the primary turbo. The object, supposedly, is that it helps draw the exhaust through at lower rpms to prevent the need for a wastegate turbo, and at full load the exhaust flow is supposed to drive against the turbine to provide added horsepower. It drives off of a gear train at the rear of the engine.

Now, for the problem. I was doing spring tillage with the tractor a few nights ago. About a round before :shf I was thinking I might be developing a fuel filter issue. Then, sudden loss of power along with strange noise. My first thought was a charge air line. Stopped the tractor and promptly noticed massive blue smoke out the exhaust and engine was running strange. Oh, oh. Got out of the tractor and discovered the primary turbo and exhaust manifold was glowing ORANGE, similar to a ripe pumpkin. My first thought was that it was possible it might take off on the oil, so I sat in the tractor with foot on the clutch and in gear so I might have a chance to kill it if needed. Shut it down after about 5 min.

Next morning, pulled exhaust off and found primary turbo was toasted. After further investigation, found that I was able to spin the compound turbo by hand. Pulled it off, and found I could turn the drive gear also. My thought is when the compound turbo stopped spinning, it created a great deal of backpressure for the primary turbo, causing it to overheat and fail. So, here's the dilemma. The power unit, clutch assembly, whatever you want to call the drive mechanism for the turbine is $6000. There is only one in the country. Until I can take it off and verify that it has failed and not the gear train, I am not going to order it.

My question, pardon the long post, is this. Does anybody have any experience with this situation. No dealer in this state has ever seen this happen, and nobody can tell me how that drive unit functions with any certainty. I don't have time to dig further due to planting right now.

 

[lantraxco]

What makes you think the compound wheel stopped spinning?

A little quick research seems to indicate that that is a VOITH compound unit and almost certainly has a fluid coupling between the turbine wheel and the flywheel gear, probably filled with engine oil. Kinda makes sense, would allow for needed slippage when one force is ahead of the other. So, I would think it's meant to slip so it follows you would be able to turn it by hand with little resistance, these turbine wheels are designed to turn in the tens of thousands of rpm when working.

If there's no visible damage to the compound turbine wheel and no signs of it seizing up, then I would be looking at upstream issues, either an overfueling issue from bad injector/ECU problems, or a severe oil intrusion issue on the hot side of the main turbo, perhaps a plugged drain line? Or the turbo just decided to bite the dust all on it's own and a new turbo will maybe be all you need to get her back in the dirt.

Be interesting to see how this turns out, it's sure a new world every year these days.

 

[Scrub Puller]

Yair . . .

It drives off of a gear train at the rear of the engine.

.

Not trying to be a smart a$$ and in no way being a help to Shimmy1 but as I understand it these compound turbo systems by a system of gearing actually feed power into the gear train.

As an example (say) the turbine shaft on a given turbo on a given engine was capable of producing 150 HP but it only took 50 HP to provide the (say) 20 PSI boost the extra 100 HP is fed direct into the drive train.

I believe that's how it worked with aero engines and it is a very old concept, Perkins played around with it for years.

Cheers,

 

[Shimmy1]

Found this out today, Lantraxco. Since nobody around here has ever had these issues before, they assumed the turbine was coupled directly. So, backwards we go. No oil made it through the charge air cooler. So, could a failing turbo bearing get everything that hot? Also, since it wasn't eating oil, why was it running rough? I sure hope it isn't an injector or ecm issue. If so, and caused things to get that hot, I would have to believe some fairly extensive damage was probably done to the engine.

 

[lantraxco]

Oil leaking into the exhaust side? Now I know y'all will say, "but wait, that should have exhaust pressure" but it's possible for the flow of exhaust gasses to create a vacuum as it passes through the turbine. Or if the turbo oil drain is somehow restricted. Did the turbo seize up and stop turning, or did you lose the bearing on one end or the other? Was there oil or signs of it present in the turbo exhaust outlet?

Basically any problem with a turbo you lose boost and along with that, power. The ECM *should* sense boost air, inlet manifold temp, exhaust temp, etc. and reduce fuel and maybe timing in an attempt to alleviate the problem. You should have gotten some warnings and there should be a laundry list of error codes stored in the ECM, and if it was something that would injure the engine, it should have shut down or at least gone into limp mode of some kind.

Scrub, yeah I think the venerable DC-4 had compounds on those big beautiful radials, I've only ever heard recordings but an unusual sound when the pilot calls for takeoff power! Firefighting outfit a few hours from here still flies a handful of the only ones left still earning their oats. Props and pushrods still have a place in this world, thank God

 

[Scrub Puller]

Yair . . .

Fellers, it is just a point of interest that I make . . . and my apologies to Shimmy1 if I have this wrong.

He stated . . .

It is a gear driven turbine that the exhaust goes through after the primary turbo.

The point I make is that it is not a gear driven turbine, that secondary low speed exhaust driven tubine @ about 50000 revs puts about 75 HP into the gear train through a coupling . . . he would have noticed a drop of 70 odd horse-power when the unit failed.

As mentioned it is old technology and I am really surprised to see it being marketed in the US where one would think a few more cubic inches and tweak the boost a bit would be a simpler and more cost effective and acceptable way to come up with a few HP.

Every sympathy to Shimmy1 and I hope he has no major engine damage apart from the unit which is bad enough.

Cheers.

 

[Shimmy1]

Yair . . .

He stated . . .

The point I make is that it is not a gear driven turbine, that secondary low speed exhaust driven tubine @ about 50000 revs puts about 75 HP into the gear train through a coupling . . . he would have noticed a drop of 70 odd horse-power when the unit failed.

As mentioned it is old technology and I am really surprised to see it being marketed in the US where one would think a few more cubic inches and tweak the boost a bit would be a simpler and more cost effective and acceptable way to come up with a few HP.

Every sympathy to Shimmy1 and I hope he has no major engine damage apart from the unit which is bad enough.

Cheers.

You are spot on, Scrub. When I posted originally, I hadn't been informed properly. Now that I know it's a fluid coupling, the problem becomes how to know if the coupling failed, or something internal in regards to fuel delivery to create that terrible heat. Before the incident, I was realizing some power loss. 70 HP? Seems unlikely, but I can't be sure. The engine or ecm DOES NOT have a pyrometer. Would have surely know that the exhaust was the temp of lava if it did. The primary turbo is toast. Turbine can move all over, and is drooling oil into the exhaust and intake.

What I'm thinking the plan should be is this. Get the primary turbo swapped. Leave the crossover off and fire it up. If the compound turbine spins (I believe it should, correct me if wrong), then put everything back together, install a pyrometer, and put it back to work. IF the engine seems to run ok. If I get the turbo on, start it and it is puking blue smoke out the exhaust, I guess the bank account is going to take a pretty big hit. If it runs fine and the pyrometer doesn't show anything amiss, then time will tell. But, if I get it working and start seeing 1200-1400°F temps, then my only guess is the fluid coupler is failed. Thoughts?

 

[Birken Vogt]

I would guess that if the drive system from the compound turbine to the gear train failed in the free wheeling mode, the compound might have gone over speed and destroyed itself, but I cannot fathom how it could lead to overheating of the exhaust system.

 

[Shimmy1]

I have pulled the compound turbine off of the fluid coupling assembly. Seems fine. Also, it wasn't the color of a pumpkin when I stopped.

 

[Scrub Puller]

Yair . . .

Shimmy1 .

Dunno mate, an old war horse here sticking his nose in where it probably shouldn't be but does this scenario work as a possible explanation . . . . .

1/Your primary turbo had a catastrophic failure, dropped the boost and over-fuelled with oil going into the engine on the compressor side

2/ The secondary turbo kept trying to supply power into the gear-train.

3/Some glitch in the fuel management system allowed full fuel even though the engine was not getting enough air to burn it

Condition 1/ or 3/ could account for the glowing manifolds and condition 2/ would contribute to an overload condition which would exacerbate the problem.

Those are just off the cuff thoughts.

Incidentally, things may be different with modern engines but as a rule a bit of colour in a manifold on high load once was common and I have seen turbo's run white hot for hours . . . white hot to the point where the housings became translucent and you could see the flicker of the rotating assembly spinning around inside.

Obviously having the presence of mind to cool it out for five minutes before shutoff means you did all that was possible to limit the damage.

If the compound unit didn't fail the power loss would have been equal to having lost boost pressure. In the old days this meant flame out the stack and rolling coal until you knocked the throttle back to where the engine could burn most of the fuel . . . I would have thought the engine management system would have the same effect.

I wish you all the best with this and please keep us posted as I find the whole concept fascinating.

As a little aside . . . other manufacturers have played around using that second turbine to run parasitic loads such as cooling, A/C, charging, hydraulics and so on. I believe the Russians have done a lot of development on this concept although I can see the variable output on mobile machinery would be a problem . . . marine and gen. set not so much but why bother?

Cheers.

 

[Shimmy1]

Thanks, Scrub. As I said earlier, there was no oil inside the charge air line on the cold side, after the cooler, where it enters the head. Could the oil have been vaporized and being drawn through, not wetting the inside? I suppose it's possible. Would have thought that would result in a runaway though. I take some comfort from your comments about the heat. I have a very hard time believing that I'm not going to have damaged pistons, cracked iron, etc. I surely hope not. This was the tractor that got a new transmission this winter, so it already owed us $20,000 this year. Oh yeah, one more thing. The engine has only 2515 hrs. on it. Barely broke in. Well, I guess it's broke in now.

 

[lantraxco]

The international nature of companies these days means you buy your favorite formerly US brand of machine and only God and the corporate powers that be know for sure what engine is in it. Apparently VOITH provides these compound setups for Daimler trucks with Detroit DD15 engines as well as the IVECO used in the CNH tractors.

I am sure one of the drivers behind this sort of expensive technology is the emissions regs, they're all measured in grams per KW/hr, so if you can pull another 70 HP out of the same engine, and most likely boost the exhaust gas stream temp a bit more (helps burn off remaining particulate) then you may be able to test qualify and engine without any further modifications to the internals. Same number of grams, more horsepower.

 

[Volvomad]

All very interesting stuff . I have been on another planet for the last 6 weeks not that I know anything about compound turbo's . I would love to know the outcome .

 

[Richardjw~]

there was something about the turbo compound failing at the output end on the bushing where it connects to the voith....vaguely recall something mentioned at a dealer meeting but never worked on them

 

[sandy]

worked for new Holland dealer at one time
got told at engine school that the compound turbo worked well in truck engines
but had issues in tractors due to different duty cycles

 

[Shimmy1]

I had forgotten about this thread. I put a new primary turbo on. Left the exhaust crossover off when I started it. Compound turbo spun when the engine started. Not much I can do now until fall's work starts. I did drive it down the road for a while, throttling up and down to try and put load on it, then checking the turbo with a heat gun. Never got over 500° F. I am satisfied, though, that the engine probably wasn't damaged by the turbo failure. Lucky I guess.

 

[Richardjw~]

you don't seem to be having much luck with this tractor :-(

 

[Shimmy1]

you don't seem to be having much luck with this tractor :-(

Truth be told, the transmission probably should have been a warranty issue, but when my buddy got it, it had 900 hrs and out of warranty. He never realized the trans had an issue until I started running it. Hopefully it's done spending our money for a long time now.

 

[Shimmy1]

Wheat harvest done, put the tractor to work. 30 hrs. on it, pulling a 50' chisel plow, everything seems to be running fine. Think we may have gotten lucky. Now we just need our scraper dealer to find us an I-180 or 1810E to rent.

 

[old-iron-habit]

Wheat harvest done, put the tractor to work. 30 hrs. on it, pulling a 50' chisel plow, everything seems to be running fine. Think we may have gotten lucky. Now we just need our scraper dealer to find us an I-180 or 1810E to rent.

Good to hear that all seems to be working as it should. Post some pics when you get a scraper on it.