VNT died, K24 swap now..

[R.O.R-2.0]

so, yea.. my VNT bit the dust.. pics to follow in the morning..

are VNTs just junk turbos? because ive seen alot failing lately.. maybe they are all getting to "that age"??

[8v-of-fury]

Maybe your 30psi spikes finally caught up to it?

They routinely go 500k+ on stock motors.

[catlin_cava]

VNTs are just junky turbos, I've always had problems with the one on my 99 since I bough it with 200K and 57k later she was still being a trouble child till it ran dry

[rallydiesel]

That's a ridiculously generalized statement. If you maintain the car properly and run it at it's intended psi range, they will last as long as the engine.

[theman53]

Many things contribute to failure. One may never know the complete cause. At any rate it is a sad day that a VW diesel goes down. I know this car will go again and good luck to doing it in a speedy fashion.

[R.O.R-2.0]

That's a ridiculously generalized statement. If you maintain the car properly and run it at it's intended psi range, they will last as long as the engine.

is changing your oil every 3-4k miles is maintenance, no?

and keeping it under 20 psi is in its efficiency range, no?

i havent spiked that turbo past 22psi in YEARS.

once i figured out what i had, turbo wise, i treated it alot better.. but now its dead..

and for the turbos lasting 500k... those are on STOCK cars..

im going to say that these turbos are JUNK for performance.. the VNT15 in general..

[catlin_cava]

My oil changes were always 10-12k on all 3 of my TDIs, my 2001 the turbo could never hold boost while driving on the higeay(vanes failure), my 99, the vanes stuck ALL the time if it was driving like a normal car(before it was tuned) and it was less bad after I ha it tuned
My 2006, the vanes failed, never abused he car at all, VNT15 turbos are junk, and I'm not the only person that's had issues with them.

Main reason I now own a N/A Daily Driver,

[8v-of-fury]

you don't know how it was treated before you got it.

you did subject this turbo to some pretty big spikes, the damage done (if any) doesn't just go away because you then started to take care of it.

You can still beat a turbo up on stock applications. if they can goo 500k+ on them a few hundred should last on a power motor..

[R.O.R-2.0]

My oil changes were always 10-12k on all 3 of my TDIs, my 2001 the turbo could never hold boost while driving on the higeay(vanes failure), my 99, the vanes stuck ALL the time if it was driving like a normal car(before it was tuned) and it was less bad after I ha it tuned
My 2006, the vanes failed, never abused he car at all, VNT15 turbos are junk, and I'm not the only person that's had issues with them.

Main reason I now own a N/A Daily Driver,

i may run ONE MORE vnt15.. i got this awesome mk2 VNT mount.. but if it gives me the finger, im never looking back.. still trying to decide how im going to fix this FU## up...

I WASNT EVEN HARD ON THE BOOST WHEN IT HAPPENED!! (maybe 5-7psi)

(and i changed my oil less than 1k miles ago)

and this turbo was fine when i did the engine swap.. i took the turbo apart and measured radial and axial play.. both were fine..

its almost like the turbo ate something.. i thought it ingested the compressor nut, but it was there.. i havent had it off to look yet, but i can feel blades MISSING.. it has atleast 2 blades missing on one side, a long blade, and a short one..

idk how it could have ingested something tho.. i have a decent air filter, and ZERO holes in my turbo intake.. something bounced around the turbo inlet, and messed up the compressor wheel bad.. maybe i will find whatever it was in my intercooler when i drain and clean it..

[libbydiesel]

VNTs aren't junk.  They are very well made turbos.  That said, they do spin a LOT faster than old school turbos.  They have also lightened them as much as possible to reduce rotating mass. 

Vanes sticking is NOT a turbo failure.  It is a failure of the vane control and engine management.  I would wholeheartedly agree that the VW vane control is poor at best and is the cause of 95% of the bad press about VNTs.  My current mechanical control designs have had ZERO vane sticking issues even running on IDI engines.  Another 4.9% of the bad press is from people who have operated them outside of the design range.  ROR, 20 psi is well outside the design range for the VNT15.  If running 20 psi is desired, then you should go with a larger VNT.  Maybe a VNT17, but that's still out of the design range for that turbo. 

If the turbo ingested something, then that, again, is not a turbo failure.  The failure was whatever allowed anything other than clean air and crank vent fumes to reach the turbo.

[R.O.R-2.0]

VNTs aren't junk.  They are very well made turbos.  That said, they do spin a LOT faster than old school turbos.  They have also lightened them as much as possible to reduce rotating mass. 

Vanes sticking is NOT a turbo failure.  It is a failure of the vane control and engine management.  I would wholeheartedly agree that the VW vane control is poor at best and is the cause of 95% of the bad press about VNTs.  My current mechanical control designs have had ZERO vane sticking issues even running on IDI engines.  Another 4.9% of the bad press is from people who have operated them outside of the design range.  ROR, 20 psi is well outside the design range for the VNT15.  If running 20 psi is desired, then you should go with a larger VNT.  Maybe a VNT17, but that's still out of the design range for that turbo. 

If the turbo ingested something, then that, again, is not a turbo failure.  The failure was whatever allowed anything other than clean air and crank vent fumes to reach the turbo.

ok, if 20 psi is out of the efficiency range, they why do they spike 30+psi on a stock(ish) TDI?

Catlins turbo, while it was working properly, often spiked 30 psi.. hell, i blew a 1.5 apart with that turbo, making almost 40 psi..

and like i said, the VNT is too new of a technology, and not perfected.. ive seen lots of DEAD VNTs lately, fords, chevys, dodges, VWs..

my opinion, is that they are junk.. sorry if you dont agree..

[libbydiesel]

If the vanes stick at all then they can easily spike.  Again, that's an control/engine management issue and not the fault of the design of the VNT turbo itself.  I agree that the stock vane control stinks and causes almost all of the issues.

What about them do you feel is junk?  Do you think they should be designed to withstand ingesting something without breaking fins.  LOL!

[bajacalal]

I'm gonna side with ROR here and agree that VNTs are junk, just based on what I've heard from people's experiences with them.

I know someone who has gone through 3 or 4 of them (admittedly, in a performance application, it's a TDI in a 240 Volvo wagon) and others that have gone through 1 or 2.

Some had the whole thing lock up, most had experienced vane control failures. The Volvo guy, I think has had better luck with the Chinese knock-offs than the genuine stuff.

The added complexity makes for a less reliable system and they aren't worth it IMO.

[745 turbogreasel]

The big 3 replace them as a bad turbo if OBD says they went out of range, they don't even look to see if it was the controller, the turbo, or what.
Much of the time, it's a slipped plastic gear in the black box, or a spot of soot on the vanes, not the turbo at all.

I've seen a couple outlast 2 engines. *shrug*

[8v-of-fury]

ok, if 20 psi is out of the efficiency range, they why do they spike 30+psi on a stock(ish) TDI?

Catlins turbo, while it was working properly, often spiked 30 psi.. hell, i blew a 1.5 apart with that turbo, making almost 40 psi..

Could we possibly deduct that you had in fact injured this turbo way back when you were spiking 40psi on it?

The chipped TDI's that run that pressure, can as you have found out sustain the period. For a period of time, find a person that has done any long miles boosting that high.. I doubt you will, because as you have also seen, it destroys them.

Catlin had a turbo "failure" as well yes, but he also was running it up past 20psi if I do recall correctly.