Turbo dead, what caused it?

[sbiggi]

Havent got a diffinative answer yet.

Turbine shaft

The turbine bearing is extreemly loose, while the compressor side is fine.
Obviously the tubine side got hot, but was it lack of oil, or egts?

I was driving 80 miles highway a day and the turbo had less then 1000 miles on it.
And I drove 25 miles or so home after I knew the turbo went out (smoking like a chimney down the highway).

The compressor side is fine, and the thrust bearing is fine. Oil was taken from the filter housing and the bearings have no scores in them.

I'm going to ghetto rebuild the turbo this week, ie new bearings and a new piston ring on the turbine.


Thanks,
Seth

 

[99gst_racer]

Usually, when the shaft is burned blue, it is due to a lack of oil. Yours is burned a little bit, but I've seen much, much worse. When I blew my old v-trim, my shaft looked alot like yours. I also had oil in my compressor housing, slow spool, and excessive shaft play. How did the bearings look? Any debris or pieces of metal in them?

 

[project_tsi]

was that a 50 trim shaft? What make of turbo? Looks as if it were starved of oil

 

[sbiggi]

No debris or anything in the turbo.
The bearings are smooth with no scoring in them, but the turbine side was very, very loose. The bearing seemed about a 1 thousandth over sized.
The tarnish on the shaft came right out with some polish and there is no scoring.

Its a PTE 50trim.... wish I never bought it cause I have had nothing but problems with the turbo. Broken bolts and it going out fairly quick (cause yet to be determined).


I just dont know why it would be oil starved, I was running a -3 line from the filter housing.
One thing I did since then was to replace my rod bearings in an attempt to possibly increase oil pressure at idle.

 

[oldman]

1. Oil starvation like mentioned above. However, since you are blowing smoke big time, I doubt that this is your problem.

2. Boost leaks => overboosting the turbo.

3. Excessive crankcase pressure => poor oil return capacity. I just read your post in another thread where you stated that the pcv is routed to a catch can, did you hollow out the pcv or replace it with a straight fitting? If not, it can cause a lot of problem.

Good luck.

 

[sbiggi]

1. Oil starvation like mentioned above. However, since you are blowing smoke big time, I doubt that this is your problem.

2. Boost leaks => overboosting the turbo.

3. Excessive crankcase pressure => poor oil return capacity. I just read your post in another thread where you stated that the pcv is routed to a catch can, did you hollow out the pcv or replace it with a straight fitting? If not, it can cause a lot of problem.

Good luck.

I though about the excessive crankcase pressure.... the pcv valve has been hollowed out, and I also recently added a vent to the crankcase.

I think I will also make a larger return.

Thanks for the input guys!

 

[99gst_racer]

3. Excessive crankcase pressure => poor oil return capacity. I just read your post in another thread where you stated that the pcv is routed to a catch can, did you hollow out the pcv or replace it with a straight fitting? If not, it can cause a lot of problem.

Bruce, explain this one to me if you could. I dont under stand how an unmodified PCV that is routed into a catch can could cause excessive crankcase pressure.....

 

[oldman]

Bruce, explain this one to me if you could. I dont under stand how an unmodified PCV that is routed into a catch can could cause excessive crankcase pressure.....

Because the valve was designed to be sucked open by vacuum in the intake. Yes it can still be pushed open by the crankcase but it will take some buildup in the crankcase first. If you read the RRE or vfaq article about re-routing the pcv to a catch can, both said to do this. Basically you want a completely free flowing system as you're all ready sacrificing the venting capacity when you re-routed it to a catch can to keep your intake free of blow by.

 

[99gst_racer]

Because the valve was designed to be sucked open by vacuum in the intake. Yes it can still be pushed open by the crankcase but it will take some buildup in the crankcase first. If you read the RRE or vfaq article about re-routing the pcv to a catch can, both said to do this. Basically you want a completely free flowing system as you're all ready sacrificing the venting capacity when you re-routed it to a catch can to keep your intake free of blow by.

Very interesting; I didnt know that. Thanks for the insight, Bruce. Would you happen to know what the thread is on the PCV?

 

[oldman]

Very interesting; I didnt know that. Thanks for the insight, Bruce. Would you happen to know what the thread is on the PCV?

You're welcome. The article calls for 1/8 npt but it didn't fit quite right for me, very close though. I end up just running a 1/8 npt thread through the hole.

 

[99gst_racer]

You're welcome. The article calls for 1/8 npt but it didn't fit quite right for me, very close though. I end up just running a 1/8 npt thread through the hole.

You're the man Bruce. Thanks again.

PS - I swear, I see this damn pop-up like every other day......