Turbocharger failure

Topic: Turbocharger failure (Read 1639 times) previous topic - next topic

Turbocharger failure

April 22, 2015, 04:22:24 am

When we last moved from Tucson up to Prescott, I heard an unusual lower frequency whistling from the turbo as it came onto boost, followed by the usual high-pitched happy-turbo sound and normal boost pressure.

We've been parked for a while at a friend's house, and I finally got around to pulling the inlet pipe off the compressor side of the turbo and discovered that the compressor wheel was rubbing the housing and had a ~1/4" piece missing from one of the blades! Not sure which happened first, but I imagine an unbalanced rotor running at maybe 100,000 rpm might explain bearing wear and rubbing on the housing. Anyhow, it's down at a turbo rebuilding place in Phoenix, and I don't know yet whether it's a partial rebuild (capsule replacement) or a full replacement. I'm hoping that the piece that came off is stuck in the CAC (looks like it would have been too big to go through.)

For you heavy truck folks, how often should one expect to have a turbo failure?

Re: Turbocharger failure

Reply #1 – April 22, 2015, 07:11:39 am

You are lucky you listen and know your coach. It could have ended much worse no matter what your repair is.

Re: Turbocharger failure

Reply #2 – April 22, 2015, 09:41:18 am

My CAT 3176B preventative maintenance manual recommends turbo rebuild/rxchange at 40,000 gallons of fuel, 250,000 miles or 5000 hours. Air compressor is on the same schedule for rebuild or exchange.

Re: Turbocharger failure

Reply #3 – April 22, 2015, 10:54:40 am

Ouch - We are in Paulden for a few days yet if you need my help.

Re: Turbocharger failure

Reply #4 – April 22, 2015, 10:57:14 am

Or the blade failure could have been caused by turbo bearing failure caused by coking which allowed the blade to contact the housing causing the blade to fatigue and a chunk to come off.

Are there any marks on other blades to suggest the turbo ingested something?

Perhaps the rebuilder may be able to point to a cause after disassembly. Also, they may be able to figure the chances of the blade traveling through the intercooler. A quarter inch is pretty big. An out of balance shaft can cause seal failure allowing oil to be sucked into the engine resulting in high EGTs and engine damage.

Nothing wrong with Rick's suggestion of turbo replacement at 250K. If planned ahead, turbos are pretty cheap and easily owner replaceable. Ebay is a good place to check availability and prices.

Good time to point to fast idling your engine for several minutes after a medium to hard pull before shutting down. Oil temperature takes a lot longer to come down compared to coolant temp and high oil temperature and related heat soak will form coke in a turbo unless synthetic oil is used. Synthetic oil has it's drawbacks for engines not started frequently.

Dave, excellent heads up awareness! Lots of times, little clues like you heard are just ahead of a potentially costly failure. John and Rick's comments are right on.

Pierce

Re: Turbocharger failure

Reply #5 – April 22, 2015, 11:05:02 am

I have been fortunate in that I have never had a turbo failure in any of the OTR trucks, the RVs, or the diesel cars and pickups I have owned. The lowest mileage I have had on any of those is 123,000 on the 6V93 in my current Bluebird Wanderlodge. I got 396,000 on a 1998 6.5 Chevy, 198,000 on a '95 6.5, I put a little over 500,000 on a 70s model 1693 Cat, 365,000 on a 70s model 350 Cummins, & I don't even know how many miles on various Detroits I had. I AM pretty anal about the correct oil for the engine, oil change intervals, and a warm up after cold start/cool down before shutdown period on my engines.

TOM

Re: Turbocharger failure

Reply #6 – April 22, 2015, 11:20:17 am

Quote from: OldManSax – April 22, 2015, 11:05:02 am

I AM pretty anal about the correct oil for the engine, oil change intervals, and a warm up after cold start/cool down before shutdown period on my engines.
TOM

Yes, if you do those things, you have house odds. Our 300SD has 440K on the original turbo.

Pierce

Re: Turbocharger failure

Reply #7 – April 22, 2015, 01:01:36 pm

Thanks for comments & suggestions!

There were no obvious marks on the rotor to indicate ingestion of hard objects, and the exhaust side looked OK at brief examination, but the rebuilders will probably have more insight. I have been puzzled for a while by higher than normal EGT under heavy load at torque peak, so maybe there was journal leakage. And parenthetically, I've had the coach to several Cummins dealers to evaluate high EGT over the last year... Hmmm... Did have the CAC tested for leak down, and if there were signs of oil leakage, I would have thought someone would have noticed it then. I'll check for journal oil leakage signs later this week, but I have also been anal about running the engine for 3-5 minutes before shutdown, and more if just after a hard pull. May put a vacuum on the oil supply line to check for blockage. I have one of those hand vac units ("Mity-Vac") which has not been pulling its fair share of the tool load recently...)

More on this after I get a report from the rebuilder.

Re: Turbocharger failure

Reply #8 – April 22, 2015, 01:27:22 pm

Just curious how high your EGT was getting and if you are monitoring it before the turbo or after?

Re: Turbocharger failure

Reply #9 – April 22, 2015, 02:06:10 pm

EGT probe should be as close to the exhaust manifold as possible (or drill and tap it). The further away, the lower and less accurate the reading will be. The EGT should not exceed 1200 degrees max at the manifold for engine longevity. Expect to see 2-300 degrees lower after the turbo.

Pierce

Re: Turbocharger failure

Reply #10 – April 22, 2015, 04:46:10 pm

We just don't have a "usual" mileage life to expect from a turbo Dave.. Your paying attention and knowing when something isn't right saved you a lot of money..

Re: Turbocharger failure

Reply #11 – April 22, 2015, 07:08:52 pm

Dave K,
If you go to my profile and click on the Media tab there's a Turbo Technicians Guide from Detroit Diesel that you might find interesting. It has a lot of failure pictures with lists of causes.
Maybe this link will work: http://www.foreforums.com/index.php?action=profile;area=aeva;u=983

Re: Turbocharger failure

Reply #12 – April 22, 2015, 10:15:10 pm

Sorry to hear about your problem. Just happened to be looking for something else in my engine manual today and reading that in case of turbo charger failure that the Charge Air Cooler should be cleaned internally.

Re: Turbocharger failure

Reply #13 – April 22, 2015, 11:55:09 pm

Quote from: rsihnhold – April 22, 2015, 01:27:22 pm

Just curious how high your EGT was getting and if you are monitoring it before the turbo or after?

The probe is in the pipe right after the turbo. I had some qualms about drilling and tapping the exhaust pipe before the turbo, since 8.3's and ISCs have a tendency to crack exhaust pipes...

Temps I was seeing were typically running 900, and might get momentarily up to 1100, followed by a swift backing off on the throttle and downshifting. I was told by Cummins techs that 1100 after the turbo = 1300 before the turbo, so I use that as an absolute upper limit. I've been told by several Cummins techs that full throttle at RPMs higher than torque peak (I use 1500 rpm), would not harm the engine or result in high EGT, and not to worry

Nevertheless, I have seen high EGT under full throttle at 1500 and above and quickly backed off.

Re: Turbocharger failure

Reply #14 – April 23, 2015, 12:04:06 am

Quote from: Jerry Whiteaker – April 22, 2015, 10:15:10 pm

Sorry to hear about your problem. Just happened to be looking for something else in my engine manual today and reading that in case of turbo charger failure that the Charge Air Cooler should be cleaned internally.

Definitely on the list, but first will be to look in the inlet end of the CAC with my borescope to see if the piece is visible, and then to run a large shop vac into the CAC input with a clean air filter (will buy an auto air filter from Autozone) on the CAC output.
Suggestions? Really don't want to remove and wash the CAC!

Re: Turbocharger failure

Reply #15 – April 23, 2015, 12:53:52 am

You won't want to put a filter there thr high pressure will blow it to pieces.I have had 2 tutbo failures on my semi both times ingesting debris in ftom the filters duct. 1st time an aluminum duct had dropped fown and chafed area on the bottom and a small aluminum piece was injested.boom turbo went. Second time I had oil change place replace air filters and they left debris in air filter canistee turbo went boom! Alwsys inspect air filter canister and ductwork whenever opening up to check filters.vacume out can then install new filter. If the piece is small like you say it probably will be fine where it lays I doubt it is going to travel through the cac tubes as small as they are . I would leak test the cac to make sure it didnt create a small hole when it went flying.You got lucky this time! Usually it's turbo and cac.labor etc ugh!

Re: Turbocharger failure

Reply #16 – April 23, 2015, 01:10:15 am

Quote from: stump – April 23, 2015, 12:53:52 am

You won't want to put a filter there thr high pressure will blow it to pieces.I have had 2 tutbo failures on my semi both times

No the additional air filter is only temporary to clean the air coming into the CAC while I vacuum out the other end. Absolutely wouldn't put a filter in series with the intake sir system!

Re: Turbocharger failure

Reply #17 – April 23, 2015, 01:14:22 am

Great advise to check the canister & housing when replacing the air filter or watch over others doing the replacements!. I've only had Cummins do that replacement when I didn't do it.

Re: Turbocharger failure

Reply #18 – April 23, 2015, 01:22:38 am

cheap harbor freight borsecope inside the charge air cooler.

Re: Turbocharger failure

Reply #19 – April 23, 2015, 02:43:20 am

Too late for that

... I've already got an expensive Bosch one...

Re: Turbocharger failure

Reply #20 – April 23, 2015, 03:54:29 am

Quote from: Dave Katsuki – April 23, 2015, 02:43:20 am

Too late for that ... I've already got an expensive Bosch one...

Well at least now if I need one I know who to call!

Re: Turbocharger failure

Reply #21 – April 23, 2015, 10:42:59 am

Quote from: krush – April 23, 2015, 01:22:38 am

cheap harbor freight borsecope inside the charge air cooler.

HF or Amazon has USB borescopes for $20. Plug into a laptop and either view or capture video or stills. LED light built in. Noticed a 10 meter model for less than that. I used ours for interior bulkhead tubing inspection.

On the other hand, inexpensive borescopes are only a fairly recent development.

Pierce

Re: Turbocharger failure

Reply #22 – April 23, 2015, 11:54:28 am

Dave, I would not worry about taking that CAC off as I can tell you it is a simple process and bet you would have it off and back on in a day, even with cleaning.
This is a good time to clean out debris between the rad and CAC as well. So, my advice to you is take 2 days and do all of this as well as pressure test the CAC while off. It is 2 days to here so if you want to come on up we can do this and remove wet tank while over thi pit!!!
Fix all your problems at once.
JohnH

Re: Turbocharger failure

Reply #23 – April 25, 2015, 12:59:09 am

Got the turbo back from the rebuilding shop. They could reuse the compressor housing, but the turbine housing had cracks, and the turbo cartridge (CRHA -Center Housing Rotating Assembly) was quite shot, so of course replaced. The manager was not able to tell the cause of failure, but said it could have been some ingested foreign object or fatigue failure, either of which would have cause a cascading failure, which you can see in the photos of the old compressor wheel.
Now that I can see all the other pieces missing (some of which may have broken during disassembly?), I will definitely try to pull the CAC and flush it. Think there may be enough clearance under the side of the rig, but will measure and see. I'll also take out the filter and totally inspect the filter housing and intake ducting, since the turbo guy said sometimes the pieces can get thrown into the intake ducting, and might then later be ingested by the new turbo, which would not be good.

Total for rebuilding was $877 plus tax. A new one seems to be running about $2k, so definitely worth it to rebuild. The company I used was Turbo and Electric in Phoenix, and I've been quite satisfied with their service.

Re: Turbocharger failure

Reply #24 – April 25, 2015, 07:38:57 am

Dave,

Price seems quite reasonable all things considered. Hopefully you will find an undamaged & clean CAC upon inspection.

Larry

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