Advice on the condition of this turbo? Thanks.

[kevinmrowland]

Advice on the condition of this turbo? (now whole motor)Thanks.

I was hoping any of you kind folks with more turbo experience than myself could tell me your opinion of this turbo?

I started burning through oil pretty quick, compression is great across the cylinders, turbo was suspect, drove a little more an started to see oil in the intake and exhaust.

Got the parts for the rebuild, this was it before disassembly:




And such a sinking feeling when it feels just about the same after $139 of new parts.





So what say you?
Toast?
Any life left in it?
$800 for a new turbo is not looking very appealing at the moment. :whoops:

Thanks for any feedback.
KR

 

[Dougal]

That amount of play is perfectly normal.

I would look into your crankcase pressurising and pushing oil out of your turbo oil seals. Your turbo is the innocent victim here.

 

[kevinmrowland]

Well that's one positive vote, thanks Dougal.
I've got no experience with turbos to draw from, just the numbers in the book.
It does have way more play then it did 7 years ago though.


For the crankcase pressure to be way off I would think the compression would show something suspicious though? My lowest cylinder is 465, with the highest being 560, it's a bit more of a spread than I would like but in the upper end of spec overall still.

I just have the OE style valve cover vent tube vented to a bung on the air cleaner, no liquid oil build up, just the regular fine mist.

KR

 

[Dougal]

If your crankcase pressure is getting up, it doesn't mean you have to launch into a rebuild. Fitting a bigger or free-er flowing breather setup may help. But the ~20% variation you've got does suggest a problem that will need looked into at some stage.

Restrictions in the intake (air-filter etc) can also cause a turbo to lose oil through the compressor side. How is your overall oil consumption?

 

[kevinmrowland]

That's what sparked this, oil consumption went from nothing (as in, ~12oz in 6k miles) to 3 quarts over 1200 miles out of the blue.
Puffs of blue smoke out the exhaust, especially coming off sitting at idle, actual oil droplets leaking out the exhaust gasket where the pipe bolts to the turbo elbow. (found more evidence of oil leaking out the hot side than the cold)

I've had just a 3/4" vent line, straight from the valve cover to the air can, not been asking it to go through any filters or anything.

 

[Dougal]

It may be rebuild time. I have found in the past that the final stages of an engine going from good to unusable happen very quickly. It's a vicious cycle that feeds on itself.

But check the head first. Valve guides and seals can create an oil consumption problem and are a little easier to fix than pistons/cylinders.

 

[diesel60]

I had a Mercedes diesel come in with the same symptoms, owner had put a brand new turbo on thinkin it was the problem. It ran great, but smoked like crazy and had oil leaking from the exhaust side of the turbo. After pulling the turbo for further inspection, I found oil in the exhaust manifold, pulled it and found the oil coming from #4 cyl, popped the valve cover off and found a broken exhaust valve guide. It's possible that your turbo had a bad seal in it allowing oil to go past it as well. Have you put it back on and run it yet? I'm in Lebanon, about 40mi north of ya and would have no problem coming down there to help ya out if you need it.
Brian

 

[kevinmrowland]

Thanks Brian, I'm putting it back in right now, figure I might as well see what happens. Change one thing at a time you know.

I was happy to see that the inside of the exhaust manifold was dry, no excessive build-up either, just normal steady carbon everywhere.

I know that this turbo had been rebuilt before, it could have been done with crap parts and the seals just wore out, I did find evidence of the turbo itself leaking.
I've got my fingers crossed on this one, have basically done as much as I can afford so if it doesn't fix it it wont get fixed.

 

[Dougal]

Turbo seals aren't air or oil-tight. They are a labyrinth seal which always passes air and exhaust. They don't normally wear out or go bad, they usually outlast the engine they are fitted to.

When the engine is healthy, they always leak inwards, but when the engine isn't healthy the pressures can reverse and push air and oil from the crankcase out through the turbo. None of this is the turbo problem though, fix the engine problem and the turbo will run normally and not pass oil.

 

[kevinmrowland]

On board with all the comments so far, was just trying cheap stuff first.

I went ahead and put the turbo back in place, no improvement (other than I made some nice exhaust hangers at the same time). Something with the motor is not right.


I went ahead and checked the valve clearances while things were apart and they were good, intakes were perfect, exhaust were all even, but at the bottom of spec.
Inside the valve cover looks normal, nothing alarming on close examination of the top of the head (can't see much anyway).

I made a video of it back together, if anything I think it's worse.




If it was just a head gasket leak I would be getting oil in water/water in oil contamination, no?

 

[Dougal]

How many km has it done? What boost were you running?

 

[kevinmrowland]

I've put 83k miles on it, it supposedly had 116k miles on it before it came to me.
11.5 psi boost, egts run around 550-650, have never gone over 950 as a rule.

 

[kevinmrowland]

I've just spent all my money and then some fixing all the rust and rot from living back east in the salt.
My wife and I want to go on a road trip next month back to Alaska so I'm just really bummed at the moment.
This year has been like that.

 

[Dougal]

I've put 83k miles on it, it supposedly had 116k miles on it before it came to me.
11.5 psi boost, egts run around 550-650, have never gone over 950 as a rule.

Your ring-lands should have survived that okay.

 

[kevinmrowland]

I kinda drive like an old-fart.
My plan has been to keep this motor forever so I've always kinda babied it.
I consider 2500 rpm to be "high", always have an eye on the gauges, never shut it down hot, always let it warm up, it's had Amsoil heavy duty marine diesel oil for 7 years, and I change it more often than recommended as well.

Even as she sits now, she runs great, excellent milage and no difference in the power, temps, oil pressure, etc.

 

[ForealBoreal]

Your turbo has excessive play. I would say replace it with a gturbo as it a direct bolt up.

If you think it's a head gasket are you losing coolant? Have your injectors been done ever?
Your injectors should be cheap to rebuild as its a 1hz

 

[Tapage]

Your turbo has excessive play. I would say replace it with a gturbo as it a direct bolt up.

I've seen worse down here and still rolling .. actually I have an old turbo ( I bought it as core to rebuild ) with much more play and even bend inducer fins ..

 

[ForealBoreal]

I've seen worse down here and still rolling .. actually I have an old turbo ( I bought it as core to rebuild ) with much more play and even bend inducer fins ..

i am just saying that because he said he is out of spec. Fix or replace it is what I would do....

Kev do you have any coolant loss?
I don't know much about the ct26 but can the water jacket leak past anything and get into the exhaust?

 

[kevinmrowland]

Your turbo has excessive play. I would say replace it with a gturbo as it a direct bolt up.

If you think it's a head gasket are you losing coolant? Have your injectors been done ever?
Your injectors should be cheap to rebuild as its a 1hz

That is my inclination as well but as I dig more it seems like the general consensus is that unless there is axial (in-n-out) play or the fins actually move enough to touch something, then you leave it and run it.
I like to shoot for spec, but then sometimes the real world does not live up to that.
It makes no noise, no axial play, fins are far from touching anything, I put it back in and I still burn all that oil, so there must be something else I need to save my pennies for.

I don't seem to loose any coolant, I wouldn't say it's a 100% sealed system though, but I've never had a car that was? I suppose I have to have add a few ounces every year but I've never been alarmed by that.
There does not seem to be any oil/water, water/oil contamination though?

I've seen worse down here and still rolling .. actually I have an old turbo ( I bought it as core to rebuild ) with much more play and even bend inducer fins ..

That's what I'm finding as well, all the info in the book that make these out to be some magical precision instrument does not seem to follow through in the real world.

i am just saying that because he said he is out of spec. Fix or replace it is what I would do....

Kev do you have any coolant loss?
I don't know much about the ct26 but can the water jacket leak past anything and get into the exhaust?

I don't know much about the CT26 either. But it seems to me that the water jacket was a cast in completely separate chamber. I suppose the housing could have been cracked in such a way that I could not spot it when I checked it over, but there did not seem to be any indication of that (and the coolant holds fairly steady).




Now, I DID just have the injectors re-done. The shop said they were not in too bad of shape but the rebuild was on the edge of being needed.
Could that be connected to this? My fuel consumption did not change for the worse after the rebuild, in fact it got a touch better (average about a mile or two better per-gallon).

KR

 

[amaurer]

If you're burning 3qt/1000mi and its coming from the turbo, you'll know; the inside of your intake pipes will be soaked. I have a truck that burns 1qt/1000 and its nasty in there, you can't miss it.

a) check the intake upstream of the turbo, wherever you have the crankcase vent. If its oily there then you have bad blowby, probably a ring problem.

b) if a) is clean, check the intake downstream of the turbo. If its oily there then your turbo is passing oil, possibly a problem with the drain line.

c) if a) and b) are both clean then the problem is inside the engine, but somehow doesn't create a lot of blowby... e.g. a head problem like valve guides, gasket, etc.