GT1749VA turbo rebuild

[pat_00]

Hi all,

My '05 2.0 TDI Golf has started making the dreaded siren whining noise. Which I believe is turbo bearing related, car has done 128K.

Seems from my reading online that most people go for a new OEM replacement instead of a rebuild. Is there any reason for this? I've had turbos reconditioned in the past with good results.

Can anyone recommend a shop around Melb to do it?

[Pearce]

Anything from VW and OEM is going to be incredibly expensive... I don't know about a reconstruction but i would defiantly consider it. Call VW and find out how much it would cost to replace it. Might be a good excuse to upgrade it

[gldgti]

I re-cored a 1749VB recently... very easy job. New core from a UK supplier with uprated thrust bearing was about $430 shipped. Labour cost me nothing since I did it myself.

If your turbo is failing at 128,000km though, you might have some other issue, because really, a journal bearing turbo should go for a long time without any probs if everyhting else is working right (no overboosting and good oil supply)

Dont just replace it unless you are sure theres nothing else wrong to cause the new one to fail too quickly aswell.

[mk5_tdi]

I plan to hi-flow a gt1749 when I find a blown stocker, so easy to re-core to a standard core

[pat_00]

Is recoring something you can do yourself? I always thought turbo work involved balancing machines and specialty tools. Can you advise who you bought the core from?

I am pretty good at mechanical stuff, I did 2 years of a mechanics apprenticeship (working on old air cooled VWs). I just have little experience with turbos and diesels.

Online, I have found lots of people in the UK having turbo failure at less than 120K, seems over there these turbos have a bad rep. When I have the turbo out, I will make sure all the oil lines are clear. Doubt it's been overboosting, but will get that checked out.

[gldgti]

By re-coring you are replacing the whole Centre Housing and Rotating Assembly - a matter of unbolting the exhaust and compressor housings and swapping them over.

I cant find the email at the moment but they had an ebay uk store.....

[pat_00]

Thanks for the advice, I have found 3 places. London_turbos, nkkturbo and rapidturbos. Prices seem to be about 150 pounds for the core.

Can you give any pointers or tips for the job? I have replaced turbos before,but never had the turbine housings off.

[mk5_tdi]

Housings off is just unbolt and rebolt onto the new core, it's pretty simple

[pat_00]

Yeah, I found this on Youtube. How to Rebuild a Turbo / Easy Turbocharger Repair with CHRA Cartridge - NEW Balanced Core - YouTube

Looks easy as pie. Will have to clean the variable vanes too.

[gldgti]

Some advice:

> Be prepared for rusty/seized bolts attaching the exhaust housing to the CHRA. You will want some penetrant on the bolts and to leave them overnight/for a few days before you attempt to remove them.
> Some tools I would have handy for the disassembly:

• soft blow hammer
• ball pein hammer
• blowtorch/propane torch for heat
• a large, sturdy vice to clamp the exhaust housing while you work on the turbo
• assortment of open ended and ring spanners (8,9,10,11,12,13mm, depending on the turbo)
• 1/4" socket set
• old plastic tub and some degreaser or kerosene
• Camera
• Blue or red threadlocker

> Take some photo's of the turbo before you start to help you to orient the centre housing and compressor housing correctly when you re-assemble
> Use thread locker on all of the clamp bolts as it helps keep them in and also helps removal for the next rebuild in 150,000km time or whenever
> It might take some persuasion to actually remove the CHRA from the exhaust housing. Usually there is some corrosion which helps to stick it in there. You can safely, GENTLY tap on the exhaust housing cast steel to loosen the parts but you must take care not to damage any gasket sealing faces such as may be present on the oil drain flange on the CHRA.
> DONT use your ball pein hammer on the aluminium compressor housing. Take great care not to damage the compressor housing.

On reassembly:

> Take EXTREME care with the CHRA as the compressor wheel is exposed when the housing is not bolted up and can easily be damaged (bent blades!) by dropping even from an inch high onto a wooden bench, if you are lucky. So dont drop it!
> In light of the above, its a good idea to assemble the compressor housing onto the CHRA first so that you provide some protection to the compressor wheel.
> Take care when reassembling the vane mechanism to ensure it operates smoothly. Its quite tricky to reassembly it. Take note of the small locating pins.
> Dont fully torque up the clamp bolts until you are sure everything is seated correctly and that there is NO BINDING between the rotating assembly and their respective housings.