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General Information => General => Topic started by: R.O.R-2.0 on February 05, 2012, 08:44:23 pm
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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"??
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Maybe your 30psi spikes finally caught up to it?
They routinely go 500k+ on stock motors.
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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
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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.
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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.
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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..
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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,
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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..
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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..
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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.
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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..
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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!
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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.
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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*
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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.
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2001 TDI - stock application, no mods, Turbo would spike past 25psi on accelarations but would never hold a steady boost.
1999 TDI - at first on stock the vanes kept sticking, after 216s and Malone stage 2 at 17PsI I ha less issues, when the Turbo failed due to a run dry it's now out of range of boost.
2006 TDI - stock, well treated always well maintained by PO and me(full service record) I went from blowing smoke and over boosting to under boosting and loosing boost while driving
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Other than the one loosing oil, did you have them checked out as to what the problem actually was?
If not then a VNT failure cannot be claimed. :) That would be false information.
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The 01 is still kicking lol
The 06 was a vanes failure, dealer confirmed me the turbo was ***ed
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How were the vanes failed? I have seen them melted from excessive EGTs, but again, that's an engine management failure not a turbo failure.
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should we say FACK VNT's kev and just dual turbo mine? ;D
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Just go without the turbo... Problem solved.. ;D
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Were any of catlins turbos measured with a boost gauge or just vag com? I have heard vag com reads absolute pressure which would be about 14.7psi higher than manifold pressure. Either way they had issues, but I was just wondering.
ROR, sucks, but it will work out soon.
Why was I thinking the top end of the vnt 15 was around 15psi? I don't know if it is or not, but I seem to remember hearing that somewhere, maybe streettoys old site? Then the 17 was good to almost 20psi and then the 22 was good to 25psi??? Just numbers off the top of my head, but wondering what it should be if those are off.
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I dont know the exact cause of failure on the 2006 on the vanes, I'll I know the turbo was pooched so we bough a new car,
My 2001 was on a boost gauge its how I knew about the killer spikes. If I drove 120kph for more then 1 hour straight and slow down and accelarate again the turbo would spike past 30 and hold till the car would go into limp mode
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no turbo= less ***t to break :)
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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!
i never said mine ingested anything.. and my vanes were stuck OPEN. like wide open. least boost and back pressure possible..
and i dont expect a turbo to be able to eat a ball bearing and continue making boost..
im basing my "VNTS are JUNK" response to all my other observations of failures on other vehicles.. i mean hell, its RARE to have the original VNT on a car that has over 200k on it now..
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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..
Not speaking for Libby, but this leads me to believe that you claim your turbo ingested something.
Chris
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I've put 2 VNTs on Rabbits.
Other than vanes sticking I have had no problems.
I use boost to back mine off but there is also a knob on the dash to adjust where the turbo is sitting.
I shove the knob in and floor it, to smoke out the Cummins diesel in the truck behind me, then pull it out and leave them in the cloud.
I have a friend with a TDI that has gone through a couple. Says they both went at low boost while cruising but he hasn't done an autopsy.
Same car 2 good turbos maybe it's the car. Oil supply or something.
I'd put another one on.
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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..
Not speaking for Libby, but this leads me to believe that you claim your turbo ingested something.
Chris
i dont understand how it could have ingested something.. i have an air filter in place, and working.. i checked for chunks that would have caused damage, and found none..
i still havent even taken the turbo off yet.. dunno how bad it is, or even if theres a turbo left anymore..
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i still think it ingested something.. there were 4 broken blades on the compressor, not to mention it was ALL F#CK#D up..
bearings, what bearings?
the shaft was about broken, the second i went to twist the nut off the shaft, it snapped.. then once i got the nut loose, that end of the shaft snapped too..
after seeing the size of the shaft in these things, im never going to be running one again.. (VNT15)
yes, shaft snapped in 2 PLACES AS I WAS DISASSEMBLING IT!!!
im gonna say that VNTs are FINE for stock/low performance engines.. but i would avoid them on performance engines.. the LARGER VNTs may be better tho, but its still hard to say..
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The shafts are definitely strong enough to withstand removal and installation of the compressor wheel. Something very wrong happened to your turbo to significantly overstress the shaft. The VNT 15 shaft is intentionally small to reduce mass and spool time but as such I would still feel comfortable using the VNT15 up to about 15-18 psi (I think even at that pressure a VNT17 would be a better choice, but I wouldn't be concerned about failure). The VNT 17 has a shaft that does not have the step in it like the shaft of the VNT 15. It is much stronger and will interchange with the VNT15, but the added mass extends spool time slightly. The compressor wheel on the VNT 17 is also larger and so at max boost it is less labored.
My brand new zero mile VNT15 on my 1.9 mTDI AHU will not produce more than 6-7 psi with the vanes fully open and enough fuel for the EGTs to reach 1400° pre-turbine. I find it unlikely that you were hitting 20 psi with the vanes fully open unless you had extreme EGTs. Probably your vanes were stuck in a semi-open state.
I would never recommend operating a VNT without controlling the vanes. There's no point. There is no advantage to a VNT with stationary vanes as over an appropriately sized wastegated turbo. However, the performance advantage of properly controlled VNT turbo over the performance of a wastegated turbo is almost as significant as the performance advantage of a wastegated turbo over operating without a turbo at all.
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The shafts are definitely strong enough to withstand removal and installation of the compressor wheel. Something very wrong happened to your turbo to significantly overstress the shaft. The VNT 15 shaft is intentionally small to reduce mass and spool time but as such I would still feel comfortable using the VNT15 up to about 15-18 psi (I think even at that pressure a VNT17 would be a better choice, but I wouldn't be concerned about failure). The VNT 17 has a shaft that does not have the step in it like the shaft of the VNT 15. It is much stronger and will interchange with the VNT15, but the added mass extends spool time slightly. The compressor wheel on the VNT 17 is also larger and so at max boost it is less labored.
My brand new zero mile VNT15 on my 1.9 mTDI AHU will not produce more than 6-7 psi with the vanes fully open and enough fuel for the EGTs to reach 1400° pre-turbine. I find it unlikely that you were hitting 20 psi with the vanes fully open unless you had extreme EGTs. Probably your vanes were stuck in a semi-open state.
I would never recommend operating a VNT without controlling the vanes. There's no point. There is no advantage to a VNT with stationary vanes as over an appropriately sized wastegated turbo. However, the performance advantage of properly controlled VNT turbo over the performance of a wastegated turbo is almost as significant as the performance advantage of a wastegated turbo over operating without a turbo at all.
dude, ill tell you again..
VANES FULLY OPEN! do you want a picture of how far open they were? ill go snap one real quick.. turbos disassembled on my bench.
the vanes were pointing directly at the shaft of the turbine.. they could open no further.. they are all stuck in the position that i ran them in for almost 50k miles..
my VNT was an anomaly.. it still spooled quick, and performed great for a long time.. ive never heard anyone retain the quick spool/high boost that i had, without operating the vanes.. my VNT still built boost by 18-1900 revs, and still made 18-22psi clear to redline.. all with no vane control.. go figure..
anyways, its completely pointless to argue about this.. im almost positive that my turbo ate something. no turbo will survive eating something..
my VNT was used, with an unknown history.. it was SEIZED when i got it. im VERY surprised i got 50k miles out of it honestly.
in the grand scheme of things, this turbo actually performed AWESOME, but i DONT think i will be installing another..
im out for BIGGER and BETTER things now.. ive had my eye on compounds for quite some time, but never wanted to make the jump because my VNT still worked soo good. but, now its dead, so i have no other options rather than a conventional turbo or 2..
the other idea i been throwing around is SUPERCHARGING it.. M62 driven off the cam or something like that..
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No picture is necessary on my account.
I wasn't aware of any arguing. Were you arguing about something?
I wish you the best on your endeavors.
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No picture is necessary on my account.
I wasn't aware of any arguing. Were you arguing about something?
I wish you the best on your endeavors.
i was arguing about nothing.. but you and others have said many times before that VNTs wont make over 10psi with the vanes fully open..
ive called BS every time that subject is brought up. my turbo has its vanes open, like tips of vanes pointing directly at the turbine shaft.. to me, that is as open as the turbo gets.
anyways, no, i wasnt arguing. but if you could only get 6-7psi out of your open VNT, then you must have not nearly as much fuel as i do.. i was worried about driving my car home with no boost to be completely honest.. every time i hit more than 1/4 throttle, it would just start pouring coals.. i know i was running it hot.
anyways, still, seems like this turbo ingested something. there was too much damage to the compressor wheel for it to have just lost the bearings.. there were also pock marks all over the turbo intake, also leading me to believe that something bounced around on the face of the compressor wheel, breaking blades off as it was bouncing around..
i really dont see what could have saved this turbo.. if it ingested something, then its my own damn fault for not checking my air filter and intake tubing more carefully. i still need to pull the intercooler, drain it, and try to fish the chunks of compressor wheel, and the foreign object that destroyed my turbo..
some time this week, im going to be bolting on my K24 turbo, and fabbing up all new oil lines, and charge piping..
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So how about some pictures? Lets see what it looks like. :) Or maybe we should just keep talking about it!
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So how about some pictures? Lets see what it looks like. :) Or maybe we should just keep talking about it!
all i have, are DIRTY pieces of it.. that need washed off..
and i broke the compressor housing off it while i was removing it.. it broke off way too easy, so im thinking it cracked the backing plate when whatever it ate went thru.. then the shaft broke.. theres still some shaft in the turbo cartridge also, as well as some TRASHED bearings..
too late for pics tonight tho..
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well, i put a K24 on my car today.. its sorta mid mounted. directly under my gasser intake manifold.. LIKE DIRECTLY UNDER IT..
and the K24 is HUGE compared to the VNT.. i used to have turbo scream at idle, now you cant even tell its turbo charged till you bring the engine up in the RPMs..
now, it reminds me of a tractor puller, sitting at the line spooling the turbo.. hold the engine at about 3000 revs and the turbo starts spooling nicely..
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How much boost? How do they compare power wise
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How much boost? How do they compare power wise
i havent driven the car, just started it, and revved it a little.. i can already tell without even driving it, that its gonna be a laggy MOFO..
i need to build a downpipe, finish my oil line, and finalize the install..
it will be done soon enough tho. might be able to drive it tomorrow..
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do you want a picture of how far open they were?
Yes, please.
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i feel stupid now >:(
the K24 performs better than the VNT.
i think it even spools as quick, or maybe even quicker..
wastegate unhooked, and i peak 20psi in every gear..
its got compressor surge like a mofo tho.. like every time you shift, the turbo barks.. what gives?
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i feel stupid now >:(
the K24 performs better than the VNT.
i think it even spools as quick, or maybe even quicker..
wastegate unhooked, and i peak 20psi in every gear..
its got compressor surge like a mofo tho.. like every time you shift, the turbo barks.. what gives?
Sounds like you got the same results as I did? I'm happy as hell with the K24.
I have the same bark, most noticable about 15 psi and higher, as soon as I lift and push the clutch to shift.
Out on the freeway yesterday 5-6psi at steady 65-70mph cruise, cob the throttle and boost climbs past 15 fairly fast.
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i feel stupid now >:(
the K24 performs better than the VNT.
i think it even spools as quick, or maybe even quicker..
wastegate unhooked, and i peak 20psi in every gear..
its got compressor surge like a mofo tho.. like every time you shift, the turbo barks.. what gives?
Sounds like you got the same results as I did? I'm happy as hell with the K24.
I have the same bark, most noticable about 15 psi and higher, as soon as I lift and push the clutch to shift.
Out on the freeway yesterday 5-6psi at steady 65-70mph cruise, cob the throttle and boost climbs past 15 fairly fast.
glad our results are the same.. i was REALLY worried about the turbo bark, because its VERY loud.. yep, boost up past 15psi, then throw the clutch in, and BAAAAAAARRRRRKKKK, shift a gear, boost up, clutch in, BAAAAAAARRRRRKKKK..
i havent had much time to play yet, because i just got it driveable earlier. and only drove it about 2 miles..
anyways, i thought i was going to have a laggy power band, but the K24 spools basically just as quick as the VNT did.. im pleasantly surprised! and im also making almost 25 psi now.. i was making ~ 15psi with the VNT.. i just left the wastegate un hooked..
ive read about the MAGIC WASTEGATE on the K24 many times, so i figured i might as well just leave it un hooked, and see how it goes.. and it regulates boost pretty much perfectly, and exactly where i want it. you can still hear the waste gate blowing open when boost picks up tho, so its still functioning, but from drive pressure blowing it open, not boost pressure against the diaphragm..
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I hooked up the wastegate like stock for kicks (no MBC) and could only get 8-9 psi.
I kinda like the turbo-bark, sounds like a premature tire chirp ;D
And egt's at 65-70mph with 5-6 psi boost= 750-800F lowest its ever been!!!
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I hooked up the wastegate like stock for kicks (no MBC) and could only get 8-9 psi.
I kinda like the turbo-bark, sounds like a premature tire chirp ;D
And egt's at 65-70mph with 5-6 psi boost= 750-800F lowest its ever been!!!
yea, i was getting the waste gate to open in neutral, without even using full throttle, when i had it hooked up to a boost signal..
stock boost levels are JUST NOT ENOUGH!
and i get both tire chirp, and turbo bark now.. ;D
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thats interesting the big vnt advocate has had a change of opinion ;D
but to be fair to the vnt your vanes were not operational.
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I could never hear my turbo over the engine noise. But like I said before, my k24 started to spool around 2,000 and was full 22psi in everygear if I wanted to.
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I could never hear my turbo over the engine noise. But like I said before, my k24 started to spool around 2,000 and was full 22psi in everygear if I wanted to.
now that ive been running it, it screams just about as much as my VNT..
and it BARKS every time you shift and your in the boost.. EVERY TIME. bark..
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thats interesting the big vnt advocate has had a change of opinion ;D
but to be fair to the vnt your vanes were not operational.
i still feel kinda idiotic for not trying this sooner.. its a blessing in disguise if you ask me.. i like the K24 to be totally honest..
but i dont like that it barks soo much. it really worries me..
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More than one person told you that there was no advantage to running a VNT with stationary vanes over using an appropriately sized wastegated turbo. However, an appropriately sized VNT with functional vanes is a humongous improvement over any wastegated turbo.
Do you have a full exhaust on it? I had a K24 that barked significantly when I only had a downpipe on it. The barking went away when I added the rest of the exhaust.
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My brothers T3 will bark with just the down pipe, is it a bad thing? what exactly is it that is happening?
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Perhaps when u let off the gas the exhaust side loses all drive pressure while some pressure is left on the intake side to reverse the flow of the turbo for a second. Just a thought
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Perhaps when u let off the gas the exhaust side loses all drive pressure while some pressure is left on the intake side to reverse the flow of the turbo for a second. Just a thought
it barks till its spooled down..
it will bark if you get on the boost, and then shift..
if you drive it like a granny, then it dont bark.
also has no downpipe..
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.. weiird.
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.. weiird.
yea.. if you speed shift, it only barks for a split second..
still barks tho.. more bark with more boost.. no boost = no bark..
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Turbines work how guys? pressure differential across the wheels, stock intake/exhaust = less pressure differential, open intake/exhaust = more pressure differential. The more you hear it the better its working.
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so now that you like the k24, go even bigger try out that dodge turbo see how that runs, basically the same thing as joshs turbo but with the newer smaller faster spooling turbine wheel. its basically what i am going to use but i am sticking with the vw .36 exhaust housing vs the dodge .48