Did You know this 'Can' happen to a diesel (Death by oil)

Leading up to this, Serge had the actuator arm on his VNT turbo break, this locked the turbo into "minimum size" mode. Similar to a plugged wastegate on a small turbo.

But that would impact all cylinders evenly. It doesn't explain why #2 has gone and the others look okay.

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Originally Posted by Dougal

Leading up to this, Serge had the actuator arm on his VNT turbo break, this locked the turbo into "minimum size" mode. Similar to a plugged wastegate on a small turbo.

But that would impact all cylinders evenly. It doesn't explain why #2 has gone and the others look okay.

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Thanks Dougal

Not having a VNT to play with myself, is there any detailed drawings about, showing the inner workings of these types of turbo's ?
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Originally Posted by wrinklearthur

Thanks Dougal

Not having a VNT to play with myself, is there any detailed drawings about, showing the inner workings of these types of turbo's ?
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There are many good web-pages which show their operation. There is a good graphic on this page: MotorSportsCenter.com.
It is essentially a ring of stator vanes with variable angle (they are linked together) which works to vary the inlet angle of gas into the turbine wheel. The overall effect is an adjustable turbine housing geometry, smaller for earlier spool up, larger for better flow.

Hi All

What I was looking for is, the effect on the seals, resulting from a problem with a sticking mechanism.

Is the turbo that is used on the 2.8TGV a Garrett VNT15 or is it the larger unit?

Found this, which nearly had the exploded drawing that I was looking for.

VNT15-Turbo

Another thing to throw in the mix, what is the effect on a VNT turbo if the air cleaner is nearly blocked and a vacuum develops at the turbo's intake?
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Originally Posted by wrinklearthur

Hi All

What I was looking for is, the effect on the seals, resulting from a problem with a sticking mechanism.

Is the turbo that is used on the 2.8TGV a Garrett VNT15 or is it the larger unit?

Found this, which nearly had the exploded drawing that I was looking for.

VNT15-Turbo

Another thing to throw in the mix, what is the effect on a VNT turbo if the air cleaner is nearly blocked and a vacuum develops at the turbo's intake?
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I beleive a GT2256V is the one on the 2.8. All the small frame garretts are built in a similar way so a VNT15 diagram is still applicable. As long as the turbo can still produce positive boost the intake seal will keep passing air to the centre housing and not leak any appreciable oil outwards.

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Originally Posted by Blknight.aus

the shape of the shiney blob in the picture for pot #4.... if its oil its pooled very nicely in the shape of the valve.

an old trick for finding surface depressions is to pour a very thin film of oil onto it, the oil will pool into the low spots and surface tension will pull the oil into shape

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ok, I was looking at the head picture not the piston. I see the blob on #4 and will have a closer inperson inspection.

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Originally Posted by Dougal

I beleive a GT2256V is the one on the 2.8. All the small frame garretts are built in a similar way so a VNT15 diagram is still applicable. As long as the turbo can still produce positive boost the intake seal will keep passing air to the centre housing and not leak any appreciable oil outwards.

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I wonder if Serge could verify that for us, the next time he is near the motor?

A four part YouTube video on servicing a stuck VNT turbo.

[ame=http://www.youtube.com/watch?v=jgqDEBEOF_4]R-tech Sticky VNT Turbo Repair Part 1 - YouTube[/ame]
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markings on the serial plate on turbo:

724561-0001 GARRETT 79517 KD0030E Made in BRAZIL

compressor housing: D.M GARRETT A/R 52 M-27
turbine housing: A/R 64 M-4
actuator: WAHLER 1/7

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Originally Posted by wrinklearthur

I wonder if Serge could verify that for us, the next time he is near the motor?

A four part YouTube video on servicing a stuck VNT turbo.

R-tech Sticky VNT Turbo Repair Part 1 - YouTube
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What is it that you want me to confirm?

go to this thread: http://www.aulro.com/afvb/90-110-130...oost-lost.html

most is covered in there of the symptom, fix and result. Note, it was fixed, installed and test driven on a Friday night (short run say 3km) then saturday morning a short run (say 5 km) to my mates workshop for its oil change....the rest is history :(

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Originally Posted by uninformed

What is it that you want me to confirm?

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Thanks Serge, the info in your previous post was what I was after .

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go to this thread: http://www.aulro.com/afvb/90-110-130...oost-lost.html
most is covered in there of the symptom, fix and result. Note, it was fixed, installed and test driven on a Friday night (short run say 3km) then saturday morning a short run (say 5 km) to my mates workshop for its oil change....the rest is history :(

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I had a interesting read of that thread and well, that kept me quiet for a while.
I'm sorry Serge, but the seat of the pants dyno you used, in hindsight wasn't the way to go and I am thinking the initial damage ( No 2 injector ) was done even earlier when you had the trouble with the arm that faulted, to what extent that damage was done, is lost now with the motor run away episode.

Where I posted about a excessive amount of combustible material being fed into the motor, still stands.
Air boost pressure didn't rise enough to burn the fuel correctly, causing the piston to melt with the increased temperature.
It's debatable whether the runaway started with the oil being picked up and fed into the induction of the motor, or over fuelling by that injector being damaged and feeding a large amount of diesel directly into that cylinder.
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