1.4TDI(90) Turbo Refurb and ramblings

S

shkcjn

Member
As the proud owner of a 2004 1.4TDI(90), and a reader of this board for the past 12 months, I thought it was about time I introduced myself and said a big "THANK YOU" to all the members who have taken the time and trouble over the years to post information on this board.

Apologies in advance for what may be a lengthy contribution as I wish to detail my experiences over the last 11 months since I bought my A2.

I paid £2400 to a private seller for the 2004 vehicle with 86k on the clock,12 months MOT, no service history but mileage verified by old MOT's. It was Class D Insurance registered but I wasn't particularly concerned as I was aware that many A2's are similarly registered due to minor panel damage and few Body Repairers being willing, or competent, to repair aluminium panel damage. Mine had had the tailgate replaced.

My first job was to re-install the original Concert II stereo and remove the installed aftermarket Sony radio. The digital display works intermittently but the sound is much better. I carried out an Oil Service and bought some VW 16" wheels and the some 195/45/16 Continental winter tyres to prepare for the weather. After the winter on these tyres I have decided to replace them with 185/65/15 Continentals as I find the ride too hard on the low profile tyres. My Summer tyres are 195/55/16 which I find give a good ride and are the perfect size to give EXACT speedometer reading as compared to GPS. I also made some front mudflaps as I live in the countryside and the bodywork was getting very muddy.

For several months I was frequently having the EML coming on with various faults. These included:-
P0234 Turbo overboost
P0236 Turbo boost sensor 'a' above predicted range
P0237 Turbo boost sensor - low pressure
P2108 Throttle actuator contol module
P0101 MAF
P0299 Turbo underboost

I reset the EML each time and decided that before I physically removed the Turbo I would try the fuel additive method to clean the turbo. I used Archoil AR6600 and during the 800 miles I was adding it to the fuel the AML was absent and turbo response was better. However, when I stopped using the Archoil it was back to the same regular EML and limp mode when starting from cold. Limp mode could be removed by stopping the engine and restarting.

In late May I went on a 700 mile trip to Devon and after spending hours ticking over in traffic jams the EML was regularly coming on so I decided to take the plunge and tackle the Turbo. Having now completed this I would say it is not a decision to be taken lightly. In my early working life I was a Motor Mechanic and MOT Inspector so I know my way around cars. I was assisted with the turbo by a friend who is now retired but was a Garage Proprietor and MOT Inspector and still has a full complement of tools.

It is necessary to disconnect/remove:-
Windscreen wiper (Bitch of a job if it's never been off)
Cabin air intake
Throttle body
EGR valve
Exhaust front pipe to turbo
Intercooler to turbo pipes
Air filter to intake manifold pipes
Engine pendulum mounting.

We now have the greatest of respect for anyone who can remove the turbo from a 1.4TDI(90) without moving the offside of the engine forward to gain access to remove the Exhaust and Inlet manifolds. To move the engine forward it is necessary to disconnect/remove:-

Front wheels
Front wheel arch liners
Headlights
Front bumper and crash bumper
Offside engine mount
Oil filler, dipstick and tube
Offside of front mounting frame
Drain coolant

The offside of the engine can then be moved forward, manifolds removed and gain access to the turbo. Another pig is the oil feed pipe to the turbo. This pipe must not be bent and is secured to the engine by a very well hidden bracket. Once the turbo is out it can be partly dismantled and cleaned.
Mine, manufactured by KKK, was sooty and slightly coked. However, the variable vane mechanism was sticking and not operating smoothly. The EGR valve and Inlet manifold were also cleaned, the manifold being very dirty with a sooty sludge.

While the car was dismantled to this stage I replaced the timing belt, tensioner, water pump and auxiliary belt.

Once everything was reassembled I replaced the front discs and pads and serviced the rear brakes and handbrake.

The car is now driving beautifully. The difference in the turbo is incredible. It was good before but it now performs as if it has been chipped.

Advice? Don't consider removing the turbo unless you have patience, determination and plenty of tools - and a sense of humour!

http://workshop-manuals.com/audi/a2...charger/removing_and_installing_turbocharger/

http://vagpart.com/audi/audi-a2-a2-eu/

http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html
 
A wee bump for this opening post as it's been overlooked in the moderation queue due to embedded links ( the software does that with early posts that have links /attachments etc)
 
shkcjn said:
As the proud owner of a 2004 1.4TDI(90), and a reader of this board for the past 12 months, I thought it was about time I introduced myself and said a big "THANK YOU" to all the members who have taken the time and trouble over the years to post information on this board.

Apologies in advance for what may be a lengthy contribution as I wish to detail my experiences over the last 11 months since I bought my A2.

I paid £2400 to a private seller for the 2004 vehicle with 86k on the clock,12 months MOT, no service history but mileage verified by old MOT's. It was Class D Insurance registered but I wasn't particularly concerned as I was aware that many A2's are similarly registered due to minor panel damage and few Body Repairers being willing, or competent, to repair aluminium panel damage. Mine had had the tailgate replaced.

My first job was to re-install the original Concert II stereo and remove the installed aftermarket Sony radio. The digital display works intermittently but the sound is much better. I carried out an Oil Service and bought some VW 16" wheels and the some 195/45/16 Continental winter tyres to prepare for the weather. After the winter on these tyres I have decided to replace them with 185/65/15 Continentals as I find the ride too hard on the low profile tyres. My Summer tyres are 195/55/16 which I find give a good ride and are the perfect size to give EXACT speedometer reading as compared to GPS. I also made some front mudflaps as I live in the countryside and the bodywork was getting very muddy.

For several months I was frequently having the EML coming on with various faults. These included:-
P0234 Turbo overboost
P0236 Turbo boost sensor 'a' above predicted range
P0237 Turbo boost sensor - low pressure
P2108 Throttle actuator contol module
P0101 MAF
P0299 Turbo underboost

I reset the EML each time and decided that before I physically removed the Turbo I would try the fuel additive method to clean the turbo. I used Archoil AR6600 and during the 800 miles I was adding it to the fuel the AML was absent and turbo response was better. However, when I stopped using the Archoil it was back to the same regular EML and limp mode when starting from cold. Limp mode could be removed by stopping the engine and restarting.

In late May I went on a 700 mile trip to Devon and after spending hours ticking over in traffic jams the EML was regularly coming on so I decided to take the plunge and tackle the Turbo. Having now completed this I would say it is not a decision to be taken lightly. In my early working life I was a Motor Mechanic and MOT Inspector so I know my way around cars. I was assisted with the turbo by a friend who is now retired but was a Garage Proprietor and MOT Inspector and still has a full complement of tools.

It is necessary to disconnect/remove:-
Windscreen wiper (Bitch of a job if it's never been off)
Cabin air intake
Throttle body
EGR valve
Exhaust front pipe to turbo
Intercooler to turbo pipes
Air filter to intake manifold pipes
Engine pendulum mounting.

We now have the greatest of respect for anyone who can remove the turbo from a 1.4TDI(90) without moving the offside of the engine forward to gain access to remove the Exhaust and Inlet manifolds. To move the engine forward it is necessary to disconnect/remove:-

Front wheels
Front wheel arch liners
Headlights
Front bumper and crash bumper
Offside engine mount
Oil filler, dipstick and tube
Offside of front mounting frame
Drain coolant

The offside of the engine can then be moved forward, manifolds removed and gain access to the turbo. Another pig is the oil feed pipe to the turbo. This pipe must not be bent and is secured to the engine by a very well hidden bracket. Once the turbo is out it can be partly dismantled and cleaned.
Mine, manufactured by KKK, was sooty and slightly coked. However, the variable vane mechanism was sticking and not operating smoothly. The EGR valve and Inlet manifold were also cleaned, the manifold being very dirty with a sooty sludge.

While the car was dismantled to this stage I replaced the timing belt, tensioner, water pump and auxiliary belt.

Once everything was reassembled I replaced the front discs and pads and serviced the rear brakes and handbrake.

The car is now driving beautifully. The difference in the turbo is incredible. It was good before but it now performs as if it has been chipped.

Advice? Don't consider removing the turbo unless you have patience, determination and plenty of tools - and a sense of humour!

http://workshop-manuals.com/audi/a2/power_unit/3-cyl._diesel_direct_injection_engine_(1.2_ltr._tdi)_mechanics/exhaust_turbocharger_g-charger/servicing_charge_air_system_with_turbocharger/removing_and_installing_turbocharger/

http://vagpart.com/audi/audi-a2-a2-eu/

http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html
Click to expand...
wow this is not the easiest task but good to know beforehand. anything that was difficult to remove from the list?
 
I have removed and reinstalled turbo's in TDI90's about 6 times. First time the engine was out of the car - which helps alot. I would echo the OP view that it certainly isn't a five minute job and would NOT recommend you average DIYer, who can change their own oil and replaces their own wiper blades but has little other experience, to attempt it without adequate tools, premises, time, research and patience.

With my experience I can now get the turbo out in about half a day provided nothing goes wrong. I could probably do it blindfolded, which is useful as many of the bolts are hidden behind the engine. If the turbo has been out recently and you know all the bolts will undo (or you're lucky) then you don't need to dismount the engine other than lean it forward to create a bit of space for extraction. However if the turbo has not been touched for 20 odd years then the chances of bolt seizures is very high. This means the amount of torque required to undo (or shear off) some bolts is (for me) just not possible with the limited amount of space available.

Having said the above, I am a Civil Engineer and not a Mechanic, so you might say I am just a really keen DIYer. I have worked on my own cars for 35 years, mostly VAG and built myself a large garage designed around a hydraulic lift to extend my hobby into my twilight years. You could say I have quite a lot of old car commitment!
 
Is there anyone in the southwest with such experience who would be prepared to change my turbo for me - rather than me having to go all the way to Stoke or London? Happy to pay of course.

@Chris Warren ?
 
Hiya,

I could probably do this for you. I am about to do a head gasket on a tdi. I have an engine on my bench and I can see all the bolts that need getting at. The only ball ache seems to be the flow and return pipes for the oil feed.
 
When the turbo and EGR were replaced on my project car, they undid the upper engine mount(s) (I don't know if it was the cambelt end one only or both) and canted the engine forwards to improve access without removal. Obviously cabin air intake / wiper were off as well.
 
Robin_Cox said:
When the turbo and EGR were replaced on my project car, they undid the upper engine mount(s) (I don't know if it was the cambelt end one only or both) and canted the engine forwards to improve access without removal. Obviously cabin air intake / wiper were off as well.
Click to expand...
maybe that engine twisting and RH driveshaft out from below is one option but as no experience hard to say which is easiest. but opening rusted bolts with poor access is surely something else.
 
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