Sprinter (and other diesel) turbo maintenance.

[mjmsprt40]

I have a question, caused by my own past experience and by watching You-Tube videos of runaway engines.

The question is, is there a schedule of any kind for maintenance and/or replacement of the turbocharger? It seems to me this expensive little puppy causes an enormous problem when it fails, so it would be handy to be able to head failure off at the pass, repairing or replacing the turbocharger before it kacks and takes the engine with it--- as seems to happen so often.

While I'm thinking about it, Ford is turbocharging gas engines so they're in this mix too. I don't think a gas engine will run away the way a diesel can, but a blown turbo won't do it any good so a heads-up about when to replace it would be good for them too.

 

[paullud]

Just check your oil level for oil consumption and if you suspect a problem check your intake tube for oil. If your intake tube is pushing oil into your air to air that is the beginning stages of what could cause a runway.

 

[greasytshirt]

Just check your oil level for oil consumption and if you suspect a problem check your intake tube for oil. If your intake tube is pushing oil into your air to air that is the beginning stages of what could cause a runway.

Some turbos tend to push a nominal amount of oil all the time. Not enough to affect oil consumption noticeably, but enough to always be present in the CAC and pipes.

If one wanted to be super analytical about it, measurements of radial and axial endplay could be taken at regular intervals and the turbo replaced when they fall outside of those margins.

By scheduling these things beforehand, a couple of spares could be sourced and be ready for installation, and the old ones could then be rebuilt before they fail catastrophically and are rendered useless.

I imagine this might be a little more feasible if one was working on a fleet of similar trucks.

 

[rollincoal]

Checking the end play is normally what you would do. I had a turbo failure that happened out of the blue this past October. The turbo had 300,000 miles, about a third of it's life, when it just grenaded itself one night.

About 130,000 miles prior to the failure the motor was inframed by CAT and one of the (many) things they checked off on was the turbo which was fine. When it let go it was a complete shock.

It was also strange in that very little oil blew into the CAC. Some went into the exhaust but not enough to blow out the stacks onto my trailer. Which normally when they blow oil goes everywhere so that was odd. I guess maybe because I was empty and in a low boost situation? Who knows..

The point here is this was not expected and just happened. Most times that is how it goes when a turbo blows. But you never expect it on one with so few miles as opposed to someone pushing close to a million miles knows they're probably on borrowed time.

 

[mjmsprt40]

I put this question out here precisely because catastrophic failure of the turbo is--- well--- catastrophic. Often, it takes the engine with it if you can't shut down fast enough, with bearing failure and/or piston failure into the bargain. So, some sort of regular maintenance/replacement schedule would be great if it can be done. Rollincoal got lucky to have it happen while not under load, had it happened while running near capacity, with the turbo near its maximum, the end result could have been a lot more severe. I had it happen on Interstate 57 near Kankakee, and at highway speed a Sprinter's turbo is under load.

 

[paullud]

I put this question out here precisely because catastrophic failure of the turbo is--- well--- catastrophic. Often, it takes the engine with it if you can't shut down fast enough, with bearing failure and/or piston failure into the bargain. So, some sort of regular maintenance/replacement schedule would be great if it can be done. Rollincoal got lucky to have it happen while not under load, had it happened while running near capacity, with the turbo near its maximum, the end result could have been a lot more severe. I had it happen on Interstate 57 near Kankakee, and at highway speed a Sprinter's turbo is under load.

If a turbo has a catastrophic failure then I don't think it would do much damage beyond the air to air. A runaway situation though certainly would and that could lead to a catastrophic failure of the engine. There are quite a few videos of it on YouTube but I don't think it is all that common. It's a situation that can be prevented most of the time by staying on top of maintenance.

 

[rollincoal]

There is no way any debris from a failure is getting past the CAC into the head. I was on my way to Huntsville, AL to pick up air freight. Was only about 10 miles away from the shipper when it let go and I pulled it into a strip mall where some of the businesses were vacant. I was only 40 miles from home so avoided a tow bill and just changed it out right there in the parking lot. Very important to make sure all the debris is removed, the old air filter must be thrown away and all of that piping should be taken apart and cleaned. Debris blows back thru the filter and will destroy your new turbo in short order if you don't get it out of there. There was very little oil in the CAC but I steam cleaned it anyways. Best guess is the turbine wheel was a poor casting with a flaw in it? No warning whatsoever. New turbine wheel is machined from a billet not cast.

 

[rollincoal]

 

[paullud]

I bet everyone was impressed with the smoke coming out of the exhaust.

 

[greasytshirt]

The compressor wheel splitting down the middle like that is from fatigue failure. The centripetal forces on the compressor wheel at full rpm are enormous, approaching aluminum's modulus of elasticity. Aluminum doesn't like having forces placed on it that are anywhere near approaching the point where it distorts (unlike steel, which can take stresses like this almost indefinitely, but is too heavy for this use).

Some manufacturers have engineered their turbos to butt right up against this line, and the turbos work great but risk this damage. Other manufacturers are more conservative, but the performance of the unit suffers.

Some manufacturers have even made titanium compressor wheels (at enormous cost).

An article about Modulus of elasticity, and comparisons between different metals: Tensile Modulus - Modulus of Elasticity or Young's Modulus - for some common Materials

A pdf from Cummins, discussing turbo design, function, and failure: http://caboturbo.nl/wp/wp-content/uploads/2012/03/HTi_07.pdf

 

[gandrimp]

I had an 05 duramax I purchased new. At 110,000 the turbo actually split in half. It had a heavy duty hose clamp that split in half, dumping the variable vanes into the valley of the v8. The rebuilders I deal with all said they reused the clamp if it was in good shape ?????. I responded with "I'm sure mine was good right up til it broke". AND they said it was a common problem on that style of turbo.
All that to say you can never tell when it will happen, and it may never.

 

[ebsprintin]

When my turbo (sprinter) failed it was the control module that went. Since the controller is part of the turbo maybe that is part of the fail safe. Controller dies before catastrophic mechanical failure. Hopefully.

eb

 

[greasytshirt]

When my turbo (sprinter) failed it was the control module that went. Since the controller is part of the turbo maybe that is part of the fail safe. Controller dies before catastrophic mechanical failure. Hopefully.

eb

The variable vane contoller? Not generally. That's just another failure point.