Stripping a turbo

[Les Henson]

The turbo thats going in catflap previously burned a lot of oil due to cracked pistons, so I thought it might be wise to strip it and clean all the sticky gunk that I could see inside it.

Not such an easy job. Taking the compressor side off was quite easy, but the nuts and bolts that hold the turbo together were extremely difficult to undo and I resorted to splitting them in the end. The use of a blow torch and then gas welding torch made little difference. Some nuts would undo quite a few turns and then sieze up for no particular reason. Doing the nut back up seemed to make matters worse. There's a real danger that the studs will be damaged and therefore unuseable. The thought of the cost of a replacement turbo tended to make me very aware that a mistake could cost me a few hundred quid, but with perseverance and care I got it apart down as far as the main body. No DIY repairs can be done to the bearing, and they are ok anyway. Pictures are how I stripped it. Having now done the job I would say that apart from removing and cleaning the compressor side, there was no point to taking the rest of it apart.

The alloy compressor casing is held on by a big circlip and nothing else, so a little bit fiddly, but otherwise easy. There's a very thin 'O' ring that you need to re-use, so be careful. Remove the wastegate actuator first, which is held onto the alloy casing by two M6 bolts and attached to the wastegate arm on the hot side by a small clip. In this picture you can see the black gunk that coated everything. It was almost like treacle and took a while to remove with a petrol/diesel mix. The inside of the compressor tapers and it's very fiddly getting in there to clean it.

Once done, it looks better and air flow through it will be maximised. It's worth mentioning that the compressor casing can be rotated to a different inlet angle if you are putting the engine in a different vehicle.

This is the cast iron casing with the downpipe from the turbo removed. The 5-nuts that hold this on were murder to undo and I cut 4 of them off.

Exhaust manifold, turbo, and it's downpipe.

Compressor vanes nice and clean. These are very brittle metal and the edges are sharp.

The vanes on the hot side. They are actually only a bit sooty. I expected them to be a lot worse than they are. I doubt the thin coating of soot will make any difference to the performance of the turbo.

In this picture you can see the wastegate, there should be no resistance to the operation of this.

Picture of the opposite side.

The component parts of the turbo as far as I dismantled it.

I sprayed the individual parts with high temperaturs Sperex matt black, then baked them in the oven to help cure the paint and to improve the finish. Once assembled it looks good.

In summary - it might be worthwhile to remove and clean the compressor side of the turbo, but there's nothing on the hot side that you can fix without specialist knowledge and probably the right tools as well.

There's a high probability that dismantling a Turbo will damage it too. If you feel the need to dismantle one, either just look at these pictures and be happy, or look at the price of a new one!! That should put you off!

Les.

[Tonk]

just done this on my turbo, the nuts holding the exhaust housing on were rusted and i ended up splitting some off, 2 studs were mullered so had to replace them.

[Les Henson]

A couple of my studs don't look too healthy Tonk, I thought it might be worthwhile replacing all of them but they are as likely to be as hard to remove as the nuts were, how did you remove yours?

Les.

[Tonk]

the exhaust housing ones just unscrewed, the 4 which held the ali housin to the steel housing with the ring i had to drill out then clear out with a tap

[02GF74]

I am very disappointed you did not polish the cast iron pipe to a mirror finish

regarding the studs, have you tried running a die over them to clean up the threads? maybe worth a go - you will then get a better idea if they a good enough to holds nuts in place ... if not., there is always the metal glue option

[Tonk]

when undoing the nuts on the studs (rear exhaust housing), they seemed to start undoing thenjust spin takin the threads completely off the studs, why this should be i dont know, obviously my turbo had been together for a long time and they run very hot, fatigue?

the 4 bolts holding the ring on just snapped the heads clean off, more fatigue?, aslong as u pick up on the centre before drilling and tapping then there's no problem. i dont like using easyouts on summat which is so siezed together incase the easyout snaps cos then u're into a whole lot of agro

[Les Henson]

4 which held the ali housin to the steel housing with the ring

Steel to steel on mine, the only alloy bit is the compressor housing.

The 4-bolts came undone with no problem, just a 13mm spanner. I was well-surprised!

Just the 5-studs I reckon I need to replace..

Les.

[Tonk]

Steel to steel on mine, the only alloy bit is the compressor housing.

Les.

ah yeah sorry, gettin confused

you're right, same 4 bolts though

[jules]

My explots with turbo's come from my Quadra 4x4 turbo

I took it off due to the studs and down pipe bolts coming lose all the time. I gave it to some cast metal workers on site to get some of the seized bolts off so I could get it exchanged by turbo technics.

They striped it repaird all the creacks and polished the inside end replaced all the studs etc. and ported the manifold for a free lunch I our site canteen I was well chuffed. Funily enough they never had trouble getting there dayworks sheets signed after that.

[will_warne]

when undoing the nuts on the studs (rear exhaust housing), they seemed to start undoing thenjust spin takin the threads completely off the studs, why this should be i dont know, obviously my turbo had been together for a long time and they run very hot, fatigue?

the 4 bolts holding the ring on just snapped the heads clean off, more fatigue?, aslong as u pick up on the centre before drilling and tapping then there's no problem. i dont like using easyouts on summat which is so siezed together incase the easyout snaps cos then u're into a whole lot of agro

I've had the nut spinning thing happen before on a quad bike rear axle tensioner, I was undoing it with no load on ad it just started spinning halfway along the thread

The thing I'd be worried about with the old studs is fatigue; the last thing you want is one of them to shear when your putting the turbo back together again.

[Les Henson]

I agree Will.

Not wanting to risk damaging the turbo, I dropped the housing off at the engineering company I use for head skimming etc. For £20-30 they are going to replace the 5 studs.

Les.

[simonr]

Now you've got the thing apart, how about bypassing the exhaust turbine so the engine connects directly to the exhaust and connect the inlet turbine up as normal.

Connect the exhaust outlet on the turbo to a pair of rearward facing pipes, one on each wing.

Then, connect a CO2 fire extinguisher to the exhaust turbine inlet!

Squeeze the trigger and you suddenly have 700psi of boost. You might have to 'adjust' the boost diaphram on the injector pump a bit too

Si

[dollythelw]

sweet Si,

..........bin the stock turbo and fit a VGT in its place

.................or bin the turbo and fit a charger instead B)

[Les Henson]

Ok Si, I'll do that right away!

Could you just stand outside your house and watch out for the bits that'll go flying in all directions!! Silly man!

Les.

[OilIT]

Ok Si, I'll do that right away!

Could you just stand outside your house and watch out for the bits that'll go flying in all directions!! Silly man!

Les.

Whilst your there, is it possible to replace the shaft oil seals in the turbo on a 200tdi? I am told by bearmach that you cant get the oil seals, but just wondered if anybody had done it?

[Les Henson]

I didn't strip it any further than you see in the pictures. The vanes could be removed quite easily by the looks of it though, just 12-point (8mm?) socket at either end of the shaft. If you can't get hold of the seals then I don't suppose there's much point in stripping it any further.

Les.

[ROGUE TROOPER]

That took you 35 mins? You lazy git

[northernchris]

I didn't strip it any further than you see in the pictures. The vanes could be removed quite easily by the looks of it though, just 12-point (8mm?) socket at either end of the shaft. If you can't get hold of the seals then I don't suppose there's much point in stripping it any further.

Les.

So if you were to strip it ,how did you think you would rebalance it???????

Chris

Edited December 13, 2005 by northernchris

[white90]

Badly is my guess

[Turbocharger]

So if you were to strip it ,how did you think you would rebalance it???????

Lead weights around the circumference?

[Les Henson]

I've never completely stripped a turbo, nor an injector pump for that matter. If I had a scrap one then I would strip it partly out of curiosity, partly out of a need to know how it works, partly to help others in doing the same job and saving money, but mostly pride in being able to say that I did the job myself and did it well too.

There are always limits however, cost of doing the job, unavailability of parts/information. I feel sorry for folk that can't do a job for daft reasons such as no garage/time etc. There's a lot of satisfaction for me in being able to say that I did the job myself. So far on catflap I've only paid someone else to one job - £20 to replace the 5 turbo housing studs, and that was only because I didn't want to fork out several hundred quid for another turbo if I messed it up!

Les.

[OilIT]

Lead weights around the circumference?

hmm, hadnt thought of the balancing bit !! Sounds like a job for the experts - not me anyway !! Thanks for the eye opening replies (LOL)

[white90]

Mine was completely rebuilt by

AR turbo in Birstall

01924477747 A1 job

[white90]

By Bill Van Snorkle:

I have a Turbocharger from a friends LandRover that I brought back from Vietnam to have rebuilt here in OZ as apparently their is no firm over there willing or capable of doing the job .

The problem with this turbo is that it leaks oil into the exaust turbine housing. The bearings/bushings felt ok with a slight amount of play which is normal, because like most other turbos, these have what are called hydrodynamic bearings which take up the freeplay with engine oil pressure once the engine starts. The turbine blades appear to be in good condition too, with nice sharp edges and corners on the vanes,so I thought ''it has to be stripped at the turbo rebuilders anyway, so what have I got to lose by stripping it myself to see what makes them tick?'' Upon disassembly everything appears to be in good order with the exception of a small split ring similar in design to a piston compression ring which is the cause of engine oil escaping into the exhaust turbine area. This oil ring appears to be worth not much more than a shilling but the local Turbo shop wants $800 to rebuild the unit, stating that a full overhaul kit will need to be fitted and the unit balanced after assembly, and as they will not be fitting the rebuilt unit to the vehicle themselves there is no Warranty.

Before stripping the unit I carefully looked for areas where metal would have been removed to balance the unit after original assembly. there were none. The only areas that metal was removed were on the back of the turbines, that can only be accessed by dismantling the turbo assembly.

Some research on the Net has revealed that all turbo components are individually balanced before assembly and then rebalanced once assembled. As I mentioned earlier ,I do not see any ''post assembly'' balance marks so I am tempted to try to get hold of an oil sealing ring, reassemble the unit and ship it back to my friend.