Can I rebuild vnt turbo?

vdubber4life

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mkiv, mkiii
Ok I ask because I've heard that garrett doesn't make any pieces to rebuld their vnt turbos, and they don't allow distributors tor ebult vnt"s because they are hard to warranty and balance correctly
 

rackaracka

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Nov 15, 2001
Location
Monroe, NJ
Ok I ask because I've heard that garrett doesn't make any pieces to rebuld their vnt turbos, and they don't allow distributors tor ebult vnt"s because they are hard to warranty and balance correctly
That's the story I got from Garrett themselves. That being said - I have a rebuilt VNT15 that was done by a company that I had heard some good things about(G Pop Shop). After getting it back I got word from Franko6 that they had gotten a few rebuilt by this same shop and they all failed...

Buyer beware.
 

2footbraker

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Sep 6, 2005
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Ontario, Canada
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06 Jetta, 01 Golf
I think if the moving parts are balanced to a high rpm you should be good. The smaller the turbo, the more critical balancing is. If the shop is aware of this, than the chances of the turbo lasting are greater. Personally, I would go with someone like turbomscanada, midwestturboconnection or boostlab or another local to you shop who are aware of the tight balance requirements of our smaller, high rpm turbos.
 

davebugs

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2001 Golf TDI Automatic, MKIV rear axle bushing install tools
Actually when questioned after G-pop said they test ALL the turbo's they rebuild they fessed up to not really being able to test variable vaned turbo's.

I too was recommended to them from performance 1.8t folks.

I had them install a new "cartridge" since they could do that in 3 days and wanted a week or 2 to rebuild the turbo. Immediate overboost. The VW tech's tested everything and it had to be the turbo.

I bought a new VNT17 from Bora, they installed it (with adapter) and all has been well since.

Funny part is the turbo I sent them was fine. Car had 185k and I was planning on a turbo rebuild at 200k purely due to how many RPM's they run and the environment they work in. The tech's did some checking and my MAF was wimpy - not within spec but not bad enough to set a code. So the reason I was down on power to begin with was the MAF.

So I paid them to break a turbo and keep my car tied up for a few weeks by the time it was all over.

They were very defensive when the tech's working on the car called them to see if they had any other ideas before we sent it back.

After we sent it back and they claimed it was good it became clear they really couldn't test it completely.

Which probably means they sold it to someone else.

I've just been hesitant to post - this was a few years ago. I have PM'd members when I've noticed they were gonna try these folks.
 

Bush Hopper

Vendor , w/Business number
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Dec 16, 2007
Location
Thunder Bay and in the Bush
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97 Eurovan, 2001 Jetta and a few other
No, you can not reliably rebuild a vnt turbo. It is possible on paper, in theory, but reality is that no one so far does reliable rebuilds.
 

ryanp

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No, you can not reliably rebuild a vnt turbo. It is possible on paper, in theory, but reality is that no one so far does reliable rebuilds.
This is bull, There are companies producing OEM quality parts so rebuilt is as good as new.

Beware of the Chinese crap or companies that cannot Balance the units.
 

DPM

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Location
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Indeed. And to Davebugs comment, methinks the new cartridge was fitted- and then the turbo installed- by someone lacking in knowledge of actuator setup...
 

davebugs

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2001 Golf TDI Automatic, MKIV rear axle bushing install tools
In my case the actuator was tested using vacuum and was found to be within spec. That's the first thing the tech's checked - this isn't exactly their first time with a TDI turbo. Along with lots of stuff - even checking pinouts on the ECM, everything they could think of.

When we called G-pop shop and told them of overboost as soon as the RPMs came up and that the actualtor was working properly based on a vacuum test they got real defensive. Not trying to help but basically repeating "how could there be a problem - we know what we're doing and test every unit". Well, apparently they didn't know what they were doing and later admitted they can't test VNT turbo's.

How defensive they were and unwilling to take any responsibility is why I won't deal with them again. Everyone has issues sometimes. How they handle issues that come up is whats important. They were a definate FAIL in product and service.
 

rackaracka

Veteran Member
Joined
Nov 15, 2001
Location
Monroe, NJ
The most important thing to consider when choosing to have a turbo rebuilt is what the potential for catastrophic failure is. If you buy a questionable quality component like: a piece of plastic trim, a hydraulic hood prop, or a rear view mirror glass - and it fails - who cares? But if you use a questionable turbo its like using a questionable timing belt kit component... When it fails you will potentially be damaging valves and pistons. Is that worth saving a few hundred dollars when there is no one that will guarantee their rebuild to the point where they'll pay for the engine damage that may occurr?

If Garrett starts selling the rotating cartridge assembly, or even parts, then I would give a rebuilder a try in the future... But for know I am sticking with OEM new turbos from trusted suppliers.
 

apples12

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Birmingham, United Kingdom
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Mk5 1.9tdi Match, BMW F10 520D
Hi,
Does the same stand for KKK/Borg Warner turbos? I've read the press release by Garrett/Honeywell, over here in the UK theres quite a few good turbo rebuilders who will recondition/refurbish garrett turbos...

i've got my hands on a slightly used KKK vnt turbo (27,000km) and i was going to open it up to give it a good clean before installing it on my car once mine finally gives up the ghost... is this even possible or should i just leave it closed? shaft has pretty much no play and the car it came off was rear ended...
 

vdubber4life

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Apr 24, 2012
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mkiv, mkiii
Any traditional wastegated turbo can be rebuilt with no issues. That's what the medium duty pickup guys and big rigs do. But vnt turbo spin fast, like 200k rpms, and since garrett themselves claims the vnt cannot be balanced or rebuilt, it make me think that they are just not rebuildable. Or at least not to the point of being reliable.
 

ryanp

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I've had LOTS of turbo's rebuilt, especially PD140 'BKD' units that fail as standard often, and never had any issues at all. My turbo rebuilder has the latest VSR balancer and can balance past 200,000rpm, i'll scan a printout if anyone cares.

The basic part of a VNT turbo is no different to a W/G unit so its crazy to think this part cannot be rebuilt. The VNT mechanism parts are available new in the aftermarket.

Its like saying we can't diagnose our own problems as VW dont sell the software/cable (VAG-COM!!)
 

Frans

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Netherlands
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VNT turbos are well suited for rebuild. There are plenty aftermarket companies that even produce better parts then OE garrett.
 

vdubber4life

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ny
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mkiv, mkiii
So all of the people saying vnt's are good at being rebuilt, have had vnt turbos rebuilt and used them for many years in success?
 

Dankemp

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May 4, 2011
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Pontypool
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Audi A4 110Tdi
as ryan p said , it is no different from a w/g turbo .

you take the cartrage out of a vnt turbo and its the same as a w/g one , all be it spinning at a higher rpm .

even if they cant balance a cartrage from a vnt , you can take the wheels out and have it balanced like you would on a normall turbo .
 

ryanp

Vendor
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Jun 22, 2008
Location
Barnsley, South Yorkshire, UK
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Arosa CR - 550hp - 9.7 @ 150mph 1/4 Mile, Citigo 4x4 CR TDi - 340hp, Caddy 2.0 CR 4x4 TDI - 300+hp, Golf Mk2 Van 1.9 TDI - was 290hp, Mk5 Ibiza 2.0 FR TDi - 270hp, BMW 135d - 360hp, BMW 330d - 335hp, BMW 335d - 380hp + a few more ........

The Shootist

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Aug 21, 2006
Location
Hixson, TN
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2002 New Beetle GLS TDI
Yes...VNT turbos can be rebuilt.

No...VNT turbos DO NOT spin faster the same size wastegate turbo.(VNTs reach top speed quicker but that speed is not a higher RPM.

No...VW "Techs" did not correctly check the actuator adjustment. Vacuum has NOTHING to do with over boosting. The actuator rod length sets the baseline vane setting in the VNT, and if this setting is incorrect boost will come in slowly, or so quick the ECU cannot cut it back and over boost occurs.
 

majesty78

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Dec 7, 2007
Location
Austria/ Europe
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VW Polo ASZ
even if they cant balance a cartrage from a vnt , you can take the wheels out and have it balanced like you would on a normall turbo .
Not a good idea for a high RPM turbo size....

Something like a kkk K27 + yes, but no no on a small frame turbo....
 

whitedog

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Jul 12, 2004
Location
Bend, Oregon
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I've had LOTS of turbo's rebuilt, especially PD140 'BKD' units that fail as standard often, and never had any issues at all. My turbo rebuilder has the latest VSR balancer and can balance past 200,000rpm, i'll scan a printout if anyone cares.

The basic part of a VNT turbo is no different to a W/G unit so its crazy to think this part cannot be rebuilt. The VNT mechanism parts are available new in the aftermarket.

Its like saying we can't diagnose our own problems as VW dont sell the software/cable (VAG-COM!!)
The thing is, how many rebuilders have the balancing equipment? If your rebuilder has the stuff and access to quality parts, I'm sure that they will be at least as good as new.
 

Bush Hopper

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Dec 16, 2007
Location
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97 Eurovan, 2001 Jetta and a few other
Problem is; rebuilders do not have access to original garrett parts for rebuilds. Garrett strictly controls where the parts are going. They might have a balancer, but again, someone experienced will have to do the balancing. Some turbo shops can't balance a new custom turbo build.

Those who say hybrids do not spin fast, your wrong. Vnt turbo can spool up to over 180,000 rpm/minute. Hence the reason why they use floating journal bearings. Ball bearing turbos spin around 100,000 rpm.

Their might be some rebuilder, somewhere in the world that might be able to do it. But why?

Savings in cost are minimal.
Quality of the parts is not known.
Lack of track record. ( specially in North America ) I never seen a rebuild last longer then 2 weeks.
 

apples12

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Feb 1, 2011
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Mk5 1.9tdi Match, BMW F10 520D
Problem is; rebuilders do not have access to original garrett parts for rebuilds. Garrett strictly controls where the parts are going. They might have a balancer, but again, someone experienced will have to do the balancing. Some turbo shops can't balance a new custom turbo build.

Those who say hybrids do not spin fast, your wrong. Vnt turbo can spool up to over 180,000 rpm/minute. Hence the reason why they use floating journal bearings. Ball bearing turbos spin around 100,000 rpm.

Their might be some rebuilder, somewhere in the world that might be able to do it. But why?

Savings in cost are minimal.
Quality of the parts is not known.
Lack of track record. ( specially in North America ) I never seen a rebuild last longer then 2 weeks.

then we must be getting some pretty damn good parts over here in the UK...

granted theres only a handful of reputable turbo rebuilder with the proper tooling to calibrate and balance VNT turbo's, the savings in cost are a lot more than just 'minimal', for example i enquired about a complete rebuild on my VNT turbo - cost from turbo technics would be 275 + VAT, for a brand new turbo your looking upwards of twice that easily. thats a bit more than just a minimal cost saving...

my understanding is that the turbo rebuilders over here who have been in the trade for decades have VERY good supply lines, theres cars on the road with rebuilt turbo's still running after years, including 'hybrid' turbo's.

if you want a turbo rebuilt then send it here and we'll get it done properly!
 

majesty78

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Joined
Dec 7, 2007
Location
Austria/ Europe
TDI
VW Polo ASZ
I use a Schenck balancing rig for seperate component (pre)balancing and a turbo technics VSR for balancing the completed CHRA up to 250.000RPM depending on turbo size.

All internal bearing/sealing parts are available from Garrett because they are also used in non restricted wastegate GT series turbochargers.
You just need to know what you want.

Aftermarket balancing very often is way better done than in oem facilitys where every minute costs a whole lot of money.
But an enthusiastic rebuilder or custom turbo builder can take himself some time to get outstanding balancing results....well at least I can take this time....
 
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