Turbo trashed?

[spiffy926]

I finally got a chance to look into the oil consumption issues of my newly acquired 760. Sure enough, the compressor wheel has massive up and down movement. I've never seen anything like it, it moves probably a quarter inch.
Now I have to assume that the grinding type noises I heard a couple times on the drive home was the sound of the compressor wheel scraping on the sides of the turbo bore.
Should I even bother with a rebuild? Or should I assume that the turbo housing its self has sustained damage and just replace the whole thing?
Has anyone been so foolish to let a turbo get to this point? And had you been able to fix it?

I'll be pulling the turbo off the engine sometime in the coming weeks, and I'll be able to inspect the damage further.

[Ekus]

If that grinding sound is coming from your turbo, stop driving that thing!:eek:
Hard to tell without having parts removed, but normally a new shaft, bushing and comp wheel will be necessary, and a turbo balance after that. Way cheaper than a new one.
Remove that turbo and make a close up inspection of the parts and housing, surely housing is in good working order.
Good luck!:)

[spiffy926]

Thanks for the tip Ekus I hope it only needs a rebuild. Luckily the maiden drive from Maine was all the engine had to suffer through. Since then It has not moved until I get everything worked out.

So far I have test run the engine with the turbo disconnected, to verify that the plumes of blue smoke I witnessed on the drive home was indeed solely from the turbocharger. I was worried about poor compression because the engine also is hard to start. But sure enough, nothing but sooty diesel smoke once I had it running N/A.

Now I have the peace of mind to move forward with the project, which means I'll finally get that turbo off, and check it out.
I'm also going to change the fuel filter and clean out the injection system to try and remedy the hard starting.

[v8volvo]

That's probably only the second or third turbo failure on one of these engines I've ever heard of. Not that it can't happen but they seem to last virtually forever, for one reason or another.

Good news is that that means there are plenty of used spares around, making that probably your cheapest option (vs rebuilding), and you'll have every reason to expect that a used replacement will work fine. :D I have half a dozen of them kicking around that I'll probably never end up using.

PM me if you might be interested in one...

[spiffy926]

Cool thanks, I'll let you know.
The PO told me he found a mouse nest in the turbo so... I guess I shouldn't be surprised

[spiffy926]

So I just installed the new turbo, and at first it seemed to run great. It started easier than ever, and didn't seem to be burning any oil.
But then after I let it warm up for 20 mins or so, I tried driving it a little.
After a couple full throttle runs, to test how the boost was building, it hung at 4k rpm, and kept on dieseling. I had to chunk it into 4th to kill the engine.
It never really ran away, but rather just hung in the higher rpms.
I would describe the smoke coming out of the tail pipe to be white, maybe a tad blue-ish but also keep in mind the exhaust system is thickly coated with oily sludge.

Now I am worried my compression might be suffering.
I find it unlikely that the IP is mis-adjusted because I never had any issues of this nature running the old turbo, or running N/A.

Is it possible an intake, or exhaust leak could cause run-on?
I had to re-use gaskets when I switched the manifold and turbo.

Also would it be worth the time to flush out the fuel system before I investigate compression issues? I should also note that you can visibly see smoke coming out of the breather, and the oil cap will hop a little bit.
I'm not sure to what degree these two things are normal.

Any advice will be appreciated, thanks.

[BluevanACD2005]

Did you have a lot of oil in the intake system?

[matchless]

I have tryed that oil breathing delivering oil enough to let the engine run with 1200rpm, now i have runned a treatment and mounted a oilcatch and no more problems

[spiffy926]

The intake was basically full of oil when the trashed turbo was still running, but I had since cleaned all that out, and the new turbo doesn't seem to be leaking any oil into the intake.

But I'll try running it with the oil breather disconnected and see if it still does it.

Thanks

[v8volvo]

Did this only happen one time, or were you able to get it to happen repeatedly under the same conditions? If it only happened once, did you start it back up after stalling it and did it run normally, or try to run away again?

You'll need to figure out if it's running on oil, or on fuel.

If it's running away on oil, you should observe a decreasing oil level and lots of oil everywhere in the intake tract, either coming from the crankcase vent hose or the turbo. If it starts easily both cold *and* warm, and this issue wasn't present before, compression leakage is not the most likely cause.

No on intake or exhaust leaks causing a runaway. If there were a leak on either side you would hear it under boost.

Normal enough for some smoke to come out of the breather and a little bit of oil cap movement when running. To test if the RPM hang is due to an IP issue or oil consumption, you can disconnect the crankcase breather hose and route it into a catch can, and go for a drive... if you replicate the conditions that caused the problem before and it doesn't hang, *and* if your catch can ends up with a lot of oil in it, you've found the issue. If you don't experience both of those outcomes, likely something else.

I've had an IP failure cause loss of engine speed control before so that's not out of the question. If your pump has the kill lever on it, one test is to run a cable into the car attached to the lever so you can pull it if/when the RPM hangs... Just because shutting off the key when it's hung doesn't kill the motor doesn't mean that the issue is not in the IP, when the engine is turning at high speed the shutoff plunger may not be able to stop fuel flow. If you pull the fuel shutoff lever when it's hung and that shuts it down, an IP issue is confirmed. The shutoff lever mechanically moves the control collar so unless something is seriously broken it should always cause fuel injection to cease. Most of the manual trans cars don't have the kill lever, but the early ones ('83 and part '84) seem like they frequently do.

[spiffy926]

I ruled out the crank breather feeding the runaway by disconnecting it, and replicating the issue. I was unsure where the shutoff lever would be if I had one, but I found a nice picture over on tom bryant's site that shows it clearly. I'll check for that next.

[spiffy926]

It has been a long time, I thought I had given up on this, there was no shutoff lever on my pump and so I decided to park it and forget about it for a while.
Well the day came when I had to move it out of the way and it really didn't want to start. It took 3 attempts of cranking for 10 seconds and waiting a minute but it finally got going.
This got me thinking.... WHY have I not tried adding diesel slick to the fuel?
I let it run for about 30 minutes with a full quart of diesel slick mixed in a quarter full tank, so it was very concentrated. And sure enough, the runaway seemed to have been solved by cleaning the IP and injectors.
It will build boost, and will not hang high in the rpm when you let off the throttle.
It also starts up right away when warm now, I have yet to try to start it cold, but I hope it will start easier.

[RedArrow]

Good thinking and useful info in this thread.