Bad turbo

[beck]

My bad turbo story

While working on my little Cummins which is in the truck in my avitar I noticed the turbo had some play and was leaking oil into both the intake and exhaust. I thougth it was simple enough to put a rebuild kit into it, so I did. Cheap fix...
I finally drove it for the first time a week ago. I noticed boost on the gauge and good EGT. About 6 miles later I noticed no boost and high EGT. I limped the truck home at slow speed. I pulled the turbo and took it apart. My new bearings were shot. The bearing OD was worn down and the ID was a bit big. The wheels had contacted on both ends. By this time a few days had passed. I wanted to check the oil but figured any bearing pieces would be laying in the bottom of the pan. I set up a turbo exhaust housing with a plate on the bearing side so I could hook up the exhaust. I ran the motor to circulate and warm the oil. I had the turbo oil supply tube stuck into the turbo drain line. After the warm up I drained the oil and pulled the filter. While the filter was draining I saw metalic coming out of it. The missing bearing material was coming out of the filter. The big problem with this is on start up the filter bypasses quite a bit of oil. That means I was pumping the ground bearing material to the rest of the motor. BAD thing! Tonight I get to pull the pan to clean it out right. After the fact I realized that putting the turbo oil supply line into the return line was not the right thing to do either. The oiling system needs restriction in this line. The turbo normally supplies this. If you are taking the turbo off and running the motor plug the supply and return lines. My supply line is 3/8 double flair like a brake line. I don't know what is on yours.
The motor will run without the turbo. It is much louder. The exhaust needs to be routed into the exhaust piping. The motor will suck unfiltered air. The power will be way down. The motor will run very rich since there isn't the normal amount of air being pushed into it.

 

[Gamagoat1]

Should something that spins a bazillion RPMs, "wobble"?

How many zeros on a bazillion??

 

[steelandcanvas]

How many zeros on a bazillion??

Mike, I thought you would know that. Let me take my shoes off and I'll tell 'ya.

 

[randyscycle]

I like Gimpy's idea. Simple, no real risk and probably just more exhaust smoke. If the exhaust side of the turbo grenades, then the pieces will just exit the stack. Still got lube to the bearings, and no chance of the engine ingesting anything.

 

[gimpyrobb]

Thanks Randy, more just a modification of Ken's idea though.

 

[FreightTrain]

Gotta worry about EGTs though.Find a turbo,swap it out or tow the truck.Turbo and Non Turbo engines are not setup the same fuel curve and timing wise.A turbo tuned truck will run some MAJORLY high EGTs and you risk melting a piston.If you drive it with a locked up turbo you will really melt down something expensive cause it will both have massive backpressure and a HUGE restriction in the intake.When the MM was running I had a clogged air filter and had to climb a 2 mile grade wreckerman found in 2nd and 3rd gear to keep the EGTs below 1300 degrees(I had the needle maxed at one point before I noticed).You can swap a turbo in 3 hours if your lucky.Bring extra nuts and bolts and a good AMERICAN made cold chisel along with all the wrenches and sockets.You might have to split the nuts to get the turbo off.

 

[ken]

Beck, When you reassembled your turbo did you make sure you clocked the compressor in the exact same position as it came apart? If not the rotor was out of balence and it destoryed the bearings. Balence is very critical for turbos!
But back to the question at hand. Go inspect the turbo see what's wrong. And let us know. We could give you much better advice with a little more info.

 

[beck]

Beck, When you reassembled your turbo did you make sure you clocked the compressor in the exact same position as it came apart? If not the rotor was out of balence and it destoryed the bearings. Balence is very critical for turbos!

My turbo has the exhaust turbine with shaft and compressor wheel seperately balanced so they do not need to be clocked. This is not always the case and as you stated they must be balanced. I solved my poor rebuilding ability by buying the new one. Hopefully I will get it installed tonight.

 

[ken]

Beck, They will need to be balenced together as a rotor. Even though they have been balenced seperately. A assembled rotor has a much tighter tolarence for the amount of unbalence allowed. They usally won't last long unless they are balenced together as one spinning unit. It is nessary to rebalence even after a simple cleaning. That's a pretty sweet thuck you've got there. Is it a 66 model?

 

[chicklin]

Well, I didn't end up buying the truck. Too many unknowns and I didn't have a chance to inspect it myself. Thanks for all the info, though, it will be good to know.

 

[beck]

Beck, They will need to be balenced together as a rotor. Even though they have been balenced seperately. A assembled rotor has a much tighter tolarence for the amount of unbalence allowed. They usally won't last long unless they are balenced together as one spinning unit. It is nessary to rebalence even after a simple cleaning. That's a pretty sweet thuck you've got there. Is it a 66 model?

I had marked the shaft and compressor wheel when I took it apart and took care to line it back up, but how close is close enough? 6 miles to failure would indicate something major wrong. I will not be taking my new turbo apart that far. I just installed my smaller exhaust housing and reclocked the compressor housing. That one will go on tonight.
The truck is a '62. Thanks for the compliment.

Chicklin,
I talked with a guy that was inspecting the truck yesterday. The truck did run but had no power. It could have been the turbo as the auction description said or the injector pump, or the injectors, or just really tired. A couple hundred more will buy one that is a driver. I don't know who the new owner is but I was like you and didn't bid.

 

[chicklin]

I had marked the shaft and compressor wheel when I took it apart and took care to line it back up, but how close is close enough? 6 miles to failure would indicate something major wrong. I will not be taking my new turbo apart that far. I just installed my smaller exhaust housing and reclocked the compressor housing. That one will go on tonight.
The truck is a '62. Thanks for the compliment.

Chicklin,
I talked with a guy that was inspecting the truck yesterday. The truck did run but had no power. It could have been the turbo as the auction description said or the injector pump, or the injectors, or just really tired. A couple hundred more will buy one that is a driver. I don't know who the new owner is but I was like you and didn't bid.

It definitely went for more than I would've been comfortable with for unknown issues. Something like $1500, I think.

 

[beck]

It definitely went for more than I would've been comfortable with for unknown issues. Something like $1500, I think.

$1680 I think.