The mk3 1.9L TD power-quest

**gldgti** · 21-01-2010, 09:47 PM

worst case i guess the compressor wheel explodes because its chinese crap.

next worse would be its so unbalanced that it fatigues the turbine shaft over time and it snaps in half

next would be imbalance that chews bearings over time

anything less would be i guess ideal turbo

**Greg Roles** · 22-01-2010, 06:06 AM

I love your work ( and if it wasn't for you the diesel section would be very friggen quiet! ) but I'd be wary of making my own hybrid turbo's. At least do your research to see if anyone else has done anything close, as the imbalance could indeed be a major thing, let alone the drivability afterwards!

Love your gutsy efforts all the same! Go man, GO!

**gldgti** · 22-01-2010, 06:50 AM

Originally Posted by cogdoc

I love your work ( and if it wasn't for you the diesel section would be very friggen quiet! ) but I'd be wary of making my own hybrid turbo's. At least do your research to see if anyone else has done anything close, as the imbalance could indeed be a major thing, let alone the drivability afterwards!

Love your gutsy efforts all the same! Go man, GO!

ahh yeah i've seen this combo before, its basically the same as the merc one is anyway, but the VW hotside is very slightly different. a few dieselers have done this and report good results.... plus, if no good, i change it back again

**gldgti** · 26-02-2010, 04:32 PM

So, last Saturday we headed off for the blue mountains for an engagement party (not my own

). As we are heading up a hill, I give it the beans and at about 20psi I hear a very loud shreik from the engine - yahoo! Stop, get out, check for anything major.... nothing gives. I suspect turbo....

Anyway, to we drove all the way to the mountains and back, and I pulled the turbo on Sunday morning after obseving some HUGE lateral movement in the shaft when i removed the intake boot!r

Luckily, the noise had come from the compressor wheel ever so slightly fouling the compressor housing - it didnt even rub enough to machine much of anything off either the compressor wheel or the housing - rather just scuffed up the housing a tiny bit and burred over the back edges of the blades.

Once I had the turbo dissassembled, i found this:

These are the bronze? journal bearings you find in a journal bearing turbo. The one on the left is an oldy, but nothing actually wrong with it. THe one on the right is the newy that I pulled from the turbo. You can see that the shoulder has been "machined" away - this is not the wear surface! Infact, this machining was done by the retaining circlip that holds the bearing inside the centre housing.

I did suspect a lack of oil pressure to be the culprit before dissembling the turbo, however upon discovering this strange wear in this bearing (there are 2 in the turbo, and the other one was unmarked) I was reluctant to say that lack of oil pressure was the cause.

The idea of the journal bearing is that when the bearing housing is pressurised with oil, the oil moves both between the bearing and the shaft, and the bearing and the housing. You can see the holes in the bearing - these are to allow a flow of oil from the inside surface to the outer surface - infact, it is fair to say that the bearings "pump" oil from the middle towards the outside as they spin, as the oil is flung out by centrifugal force.

Now, it is very important, you must see, that there is sufficient slip between the bearing and the shaft - because if the bearing was to spin at the same speed as the shaft, then it would not function correctly.

I found that some minor corrosion stains were evident on the turbine shaft in the area that the offending bearing lies, and so I was simply able to polish up the shaft very nicely, which will allow the bearing to spin freely and function properly (as the other one was).

As insurance that oil starvation isnt a factor, I have also increased the size of the oil feed line for the turbo.

Once the turbo was back together with a new set of bearings and the newly polished turbine shaft, the amount of lateral play in the shaft was significantly reduced, and the turbocharger spins freely.

I have driven it to work today, and it performs very well! So, I am happy to report that the 1.9TD is still going strong

Internal injector pump mods will be coming soon - and a new, bigger clutch to boot!

**gldgti** · 22-06-2010, 06:36 PM

who would have belived it...

So after waiting 2 months for my new SPEC 210mm 6 puck sprung hub clutch to ship in from the US of A, it still wasnt here when we had to go away to tassie on holidays.... luckily it had arrived when we got back.

Also while we were away, i found that the gearbox had begun making a dull rumbling sounds on overrun, and decided it must be diff bearings going. So, once back from holidays i planned to get the car off the road.

I pulled the gearbox and decided that I didnt want to make all the special tools necessary to dissassemble the box, so I let Camden GTI do it for me. After 240,000km of hard work, it nedded about 4 different bearings. New seals, circlips, washers, etc etc etc.

While that was happening, I got the new clutch in (which is lighter than stock by a little) and a balanced/machined petrol 210mm flywheel (which is MUCH lighter that the stock diesel jobbie).

I also dove into the injector pump. Unfortunately, I managed to drop a rivet head into the pump whilst it was installed on the engine, and forthwith had to remove it, take it inside the house, find all the literature about the VE injector pump that I could and completely (well half) dissassemble it in order to get the bit of stuff out that i'd dropped in there... WOW! That is a definate experience, I tell you. I have learned so much from that one little mistake. I also spent some time cleaning up the engine bay.... pics to come. I'm just at work atm so I can't upload pics.

Happy to report however that now its all back together and running! I modified the govenor control lever mechanism a little but I will have to go back in there and do some more, because I was too sensible and have only gained enough horsepower to wet my appetite for more.... invariably this can only end badly....

Oh, did I mention that I'm going to 2 turbo's?

Oh - some might be wondering whats a diesel like with an uprated clutch and a lightened flywheel? Well, so far its great. Slipping the clutch is a little tricky but its actually not so bad that I would say its "unrefined". Its just a little..... sensitive. I havnt stalled it yet, so cant be that bad. Also, the balancing has helped no end - the engine feels much better to rev and is much smoother than it was, which is great.