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Matt
Matt, Mechanical Engineer
Category: Audi
Satisfied Customers: 21599
Experience:  BEng hons Mech engineering, in auto industry 22 years
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We have a 2005 audi a3 140bhp tdi with a high mileage (165k)

Resolved Question:

Hi,
We have a 2005 audi a3 140bhp tdi with a high mileage (165k) but the last owner had a reconditioned turbo fitted. (probably about 40k miles ago).
Last week my wife noticed a massive loss of power but it was OK the next day. She took to a garage who advised the turbo was gone so fitted a reconditioned one for nearly £700. Then this week it happened again and today the emissions light came on the dashboard.
The garage who fitted the turbo last week aren't being very cooperative, does anyone have any ideas?
Thanks
Submitted: 11 months ago.
Category: Audi
Expert:  Matt replied 11 months ago.

Hello

On any car if you get a check engine light or other fault light this typically means one or more of the sensors has failed or has a faulty connection.

The fault can be something quite simple and nothing that’s going to stop the car to something quite major that will reduce engine power and possibly stop the engine

The ECU senses this and may put the car into 'limp home' mode which typically limits the revs and the amount of power available. Usually the car is safe to drive for a short distance as the mode is intended is intended to get you home without incurring any engine damage

The quickest route to repair is to have the car plugged into a diagnostic machine which will read off the fault code stored in the ECU (providing the light is still on at this point) and indicate which sensor has failed or whether the fault is more serious.

I'd say its also worth doing some basic checks

I'd first check all the high pressure hoses post turbo/s for any split hoses or cracked metal pipes, also check the ends of the intercooler as its not unheard of to pop the end caps off under high boost.

If this is OK then check the small vacuum lines to the turbo and its connected control solenoid on the bulkhead, any cracks or leaks can give turbo issues

Also have a feel around with your bare hands with the engine running to see if you can feel any escaping gas under your touch. Another method is to use a soap and water solution sprayed onto any suspect areas - if there's a leak it'll bubble up with the engine running

Also check that the vacuum hose running to the dump / turbo bypass valve is intact with no leaks as if the dump valve is opening prematurely you'll be losing all your boost

If this is OK then remove the high pressure intake hose after the turbo and have a feel of the turbine wheel - there should be no play radially at all - but a little bit of axial / end to end float is normal

Customer: replied 11 months ago.
Thanks for that. My wife has re-booked it into the garage that fitted the turbo this week, do you think that as they told us it needed a new turbo when it presumably didn't that we should have to pay for any further work?
Expert:  Matt replied 11 months ago.

Hello

it may have still needed a new turbo so that part may be OK but its sounding like they didn't quite finish the job, or that there's something else wrong

Expert:  Matt replied 11 months ago.

Hi

do you still need help?

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