turbo went poof

[boogiethecat]

I blew my turbo last weekend as I was halfway up the Baker grade.  I'd noticed on this trip that I was only getting half the boost I normally do but didn't think it would  be anything more than a dirty air filter.  Instead, suddenly everything went to hell in an instant... lost power, so much smoke spewing out the exhaust that with the slight wind that was present I couldn't even see the freeway in front of me...eeek 

But whatever it was, was not catastrophic- oil pressure was good, the engine sounded fine, temperature was fine... just no power and lots of black smoke...LOTS
So I kept going as there was an offramp at the top about 2 miles away  Got to the top going between 1-2 mph in first, that's all it would do, blowing so much smoke that by the time I got to the offramp I had a personal CHP escort and evidently more than a few motorists had called in 911 telling them I was on fire.
In the end all it was is the rotor shaft seal went away, the rotor stuck, and the engine was left all choked up and running on massive quantities of crankcase oil.  Once I got to the top I had to use the compression release to stop it, as it was running solely on it's own enigne oil and shutting the fuel off did nothing to stop it.  After thanking the officer for the escort (he was very happy I made it off the freeway) I took it all apart, hammered out the rotor (messed up the blades, too bad), stuck a bolt in the shaft hole to seal the inlet and exhaust sides from each other, put it all back together and completed my trip.
It was a bit ugly tho for the rest of the trip... all that restriction and no turbo at 5000 feet got me honked at or flipped off about every 15 minutes for the cloud I was blowing!!  But other than needing a lot of new turbo parts, nothing else went wrong. Lotsa greasy work to do now! Unfortunately I'll probably have to buy a new set of wheels and shaft as well as the bearing assy but I'm sure it'll be less than a tow job would have.   

  Funny this was the first trip in 30,000 miles that I didn't bring ALL of my tools.  Ended up having to mickey mouse and wedge the exhaust rotor into one of my wheel holes to get the thing unscrewed, as that is usually a job for a vice.  And I had a few things held together with welding wire by the time I got her going again... but at least I had enough tools and parts to plug the oil line and take it apart, and not have to call a towtruck.

I'm SO glad I have a compression release.  Without it I'd have blown the engine up in a runaway when I finally got it restarted, as there was soooo much oil left in the intake that I couldn't reach to clean out.  So I started it from the engine's service controls with my foot firmly on the compression release lever, and it REALLY tried to run away, and spewed me with gook from head to toe as it slowly evened out.  What a mess!!!  Glad I'm happily home now, and all I have to do is wash the engine down, and send the turbo up to Don Fairchild to get repaired.

I'm left wondering what happened to the turbo... I bought it brand new from Garrett maybe 20,000 miles ago.  Shouldn't have crapped out that soon!!!

Fun with the Crown!!!

[JohnEd]

You are So cool!

[jackhartjr]

Boggie...not saying this is/was you problem...however...a lot of folks are prone to run hard...then shut the engine down without letting it cool down for at least three minutes.
When you shut it down without the cooldown you have oil in the turbo seals that can be 600 degrees plus.  With the cooldown is is more like 300 degree oil or less.
The heat in the turbo in my opinion causes most turbo failures.
Jack

[boogiethecat]

Yeah I'm aware of that one Jack- I always let her idle a few before shutdown.

It was interesting when I first installed it... I originally put it in the same line as my oil pressure gauge, and it read 25 psi as if the turbo was just a big leak.  But it spun, worked and sounded fine.  Then in it's first 5 minutes of operation it suddenly went to zero pressure.. I kinda freaked out, pulled the bus over and checked, oil was flowing fine but now there was no backpressure at all.  It still worked fine so I drove it home.

Thinking the problem, if any, was just the the turbo was at the end of a 4 foot 1/4" line and since my oil gauge was at the same point, that probably explained the zero pressure reading.  So I then moved the supply hose to it's own own oil gallery hole and took it off of the oil gauge line... the gauge came back to it's normal 50psi and everything was fine for the next 20000 miles.

  Back last year when I took my Jakes off and had Don Fairchild help me put in a new rear axle and the Telma, Don was looking at the turbo and noted that it's shaft felt somewhat sloppier than he thought it oughta be, but I told him it'd been that way from the git go and he said, ok, and it works fine, so no biggie.

I guess there was some biggie but I have no idea what... I'm thinking it's been bad since day one and just finally gave up

[NJT 5573]

I always hold the impeller with my fingers for about 30 seconds when I install a dry turbo, just to make sure I don't kill the bearings. (Don't let it spin until your sure it has oil). Sounds like the first place it was plumbed was not enough volume to keep it alive, if it was prelubed properly when it was installed.

If a turbo has the proper amount of oil going to it and the seals let go, they can burn all the oil out of the pan in a very short time. The next question is, how much oil did it take to fill it back up and are you headed for more problems? I have put 4 gallons in a Cummins when the seals let go and I ran it less than 60 seconds.

[boogiethecat]

Hmmm.  From the amount of smoke it was blowing, I'd have thought I was using massive quantities of oil.
But it was 2-3 quarts in about an hour.  I guess that probably isn't a decent indication of how much oil the turbo was getting all along though,
because there's no way to tell how much of the seals were blown and how much oil was going back into the pan vs into the intake manifold...

I'm guessing that my oil pressure is fine going to the turbo; 1/4" line only about 2' long hooked into a 50 psi oil gallery...

Cheers
Gary

[Zeroclearance]

Gary, was there FOD damage to the turbine wheel??   I would assume that you had compressor wheel rub?

The 2 main methods of failure are going to be oil supply, either lack oil pressure> high oil temperature (no cooling)>fuel dilution>oil contamination

And lastly, foreign object damage>> something impacting either the compressor wheel or turbine wheel.   With the two cycle it usually is something hitting the turbine wheel  (rings, pistons, exhaust valves, exhaust piping or failed welds).

[johns4104s]

What checks can do to be sure the turbo is good? is there any need or is it possible to grease or oil the Turbo?

John

[JohnEd]

I'm guessing that my oil pressure is fine going to the turbo; 1/4" line only about 2' long hooked into a 50 psi oil gallery...

Not the Boogie I have come to know and love!

Another possibility is that the return line is plugged.  Not hard to check.  I would want to hear "I have X#psi at the turbo".  Course, I ain't the Monkey crawlin 'round inside there.  Makes a big difference with that wish'n stuff.

Good luck Boogman,

John

[boogiethecat]

Yeah, I thought oil pressure at the turbo would be a good way to make sure things were right, but when I tried that and the gauge said zero I asked the guy at the turbo place and he said it wasn't necessary, just hook it up and go.  Later on, about 8000 miles ago, Don F also looked at it and said it oughta be fine too.
So I couldn't get a straight answer back in those days and I was very new to it all; it appeared to work fine and that was what I had to go on.

BTW the place I bought it was Diesel Services, Inc. in Grand Junction and the experience with those folks was less than favorable.  They charged me $1500 for it because it was a custom build for my application, then they shipped it to me in horribly poor packaging, and when I got here it was all bent up (wastegate assy got crunched 'cause there was basically NO packaging other than a too-large box)
So I asked for a replacement which they begrudgingly sent, but at that point I was a bad guy and they basically quit talking to me.  That's one reason I couldnt get a straight answer, and unfortunately at that time I hadn't met Don Fairchild or any of you.  Oh well...

I'll check the drain line but I'm sure it's ok... it's only 6" long and 1/2 inch in diameter.  IF something plugged that up, i've got much worse problems!!!
When Don gets through with it, maybe we'll know more....


Oh... there was no wheel damage.  It just slowed down and eventually stopped but nothing rubbed that I can see.

Cheers
Gary

[HB of CJ]

Aren't you lucky the older 743 Cummins has the manual compression release?  My old Crown with the Small Cam 855 also had one.  The mechanic showed me how to spin the mill to build up oil/fuel pressure and stuff.

Would your Jake Brake have allowed you to physically shut down the Cummins?  Reason I ask, my planned new Crown might have the Big Cam Cummins, which as far as I know, doesn't have the compression release.

Which would mean, if the turbo seals blew like what happened to you, there would be no physical way to shut down the mill from eating its own lube oil, running away and blowing up sky high?  Would a Jake prevent this?

Years ago, the old school bus Crown I drove had the Jake set up sossss if you had it turned on (single stage) and had the tranny in neutral and released the clutch pedal, the idling engine would instantly stall.

The master mechanic told me they set it up that way, but I forgot the exact reasoning why.  Anyway, could the Jake Brake clutch micro switch be set up to instantly stall a runaway engine?  HB of CJ

[boogiethecat]

Yeah the Jakes would have killed it... as would dumping the clutch in 6th which was another possibility although I never like to stop an engine that way...

Good to hear from you HB!

[Zeroclearance]

There are really no health checks for the turbo.   I tell folks the very first sign of trouble is oil showing up in the intake piping.   The exhaust will blow past the turbine side seal (similar to a piston ring blow by) and pressurize the bearing housing blowing oil out the compressor side (thru the comrpessor side seal (similar piston ring).    If you take the turbo off the engine one can measure the bearing wear.   But with the amount of labor that requires, one can install a new center cartridge.

If infact your turbine and compressor wheel did not have FOD damage, then the bearings need to be looked at.   If you oil drain is plugged, then fresh oil cannot enter the bearing housing freely to lubricate and cool the bearings.    Fuel contamination will also trash the bearings.   I'd get a oil sample.   

[JohnEd]

Boogie,

Forgive me if I am belaboring this.  The zero psi at the oil inlet would have spelled disaster to me.  I sympathize with your not having any grounding in this....neither do I.  Lots of gas stuff over the years though.  If there is zero psi at the input what reason would the oil that is there have in going thru the turbo?  The input can't be plugged as you were pumping oil into the intake and burning it as fuel.  Very strange stuff here......it can't all be true at the same time....me thinks.  There is that word again, "think".

Really look forward to hearing Don's take on this.  Not to mention Sherlock Holmes.   This is no time for levity.

John

[gyrocrasher]

  This is no time for levity.

John