Dianosis Please? Trucks horrible

[Death85e]

These turbo shafts rides on a film of oil. If the engine is NOT running (no oil pressure) You will not be able to get a real picture of the condition of the 'bearings'.

If you spin the shaft by hand, there should be a very slight resistance. (remember, there's no oil on the bearing) There should be a little end play. But the rotors should not hit either shroud.

I wouldn't condemn the turbo yet. Go back and re-check Your work. I'd almost bet that You have a boost, and/or exhaust leak.

Did You take the IP off, to tweak the fuel? Did You even adjust the fuel screw?[/QUOT


I have the factory Garrett turbo on my 94 and even with the engine off no oil being pumped into the bearings i can free spin it for about 2 minutes just by flicking it with a finger. I dont know if this is just a fluke with mine or what but maybe its something to compare to?

 

[Brutis]

These turbo shafts rides on a film of oil. If the engine is NOT running (no oil pressure) You will not be able to get a real picture of the condition of the 'bearings'.

If you spin the shaft by hand, there should be a very slight resistance. (remember, there's no oil on the bearing) There should be a little end play. But the rotors should not hit either shroud.

That's what I kept telling myself - no oil = no spin. But I really had no idea.

I wouldn't condemn the turbo yet. Go back and re-check Your work. I'd almost bet that You have a boost, and/or exhaust leak.

Did You take the IP off, to tweak the fuel? Did You even adjust the fuel screw?[/QUOT

Yes, I bought a turboed parts truck and I switched pumps as well. I have not adjusted it at all.


I have the factory Garrett turbo on my 94 and even with the engine off no oil being pumped into the bearings i can free spin it for about 2 minutes just by flicking it with a finger. I dont know if this is just a fluke with mine or what but maybe its something to compare to?

That's definitely not possible with mine.

 

[david85]

My way to check the condition of the turbo (aside from play in the shaft) is to have the engine warmed up and idling with the air box removed so you can see the blades spinning. When you shut off the engine, the turbo should freewheel for about 10 seconds after the engine stops running. Not very scientific, but it tells you if the bearings are still satisfactory. Also remember that a cold engine weather its been running or not, will have thicker oil in it and that will slow down the turbo as well.

Its with a hot engine after a recent shut down where you can get a real feel for how tight or loose the turbo shaft is.

 

[John Deere]

Even without the oil supply the shaft should spin freely. I had a 4bt cummins that oil-coked the bearings making the turbo spin harder, it's symptom was loss of power and lots of black smoke. A turbo isn't hard to rebuild, but it requires a very delicate hand and knowledge so as not to bend the shaft when removing the compressor wheel nut. But I would see about getting the injection pump timing adjusted as it does sound as if timing is off.

 

[Brutis]

Update: Blew up the motor

Thanks to all who have responded, but my ability to continue to check for problems is somewhat hampered by the fact I blew the motor about 10 minutes ago. I went to start it up this afternoon to go tow my wife's car home (bad fuel pump) and the motor ground to a halt and rattled horribly in the process. Bent or broken rods?

I noticed a tick a couple days ago (sounded like it was coming from the front - I was thinking bearing of one kind or another), but never expected this to happen.

 

[david85]

Well CRAP!

I guess now you have bigger problems to deal with than just the turbo.

Have you tried turning the engine over by hand yet?

 

[Brutis]

No, not yet. I was kind of afraid to. I'll try that if I have a socket that big.

 

[Brutis]

I just started a new thread called, Update: "Blew up the motor" since my other problems seem pretty trivial at the moment.