Audi TT (2007 year). Manual - part 51

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not 
 permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability 
     with respect to the correctness of information in this document. Copyright by AUDI AG.

♦ Cooling system tester -V.A.G 1274 B-

♦ Adapter for cooling system tester -V.A.G 1274/8-

♦ Adapter for cooling system tester -V.A.G 1274/9-

4. Radiator and radiator fans    

195

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not 
 permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability 
     with respect to the correctness of information in this document. Copyright by AUDI AG.

Procedure
• Engine must be warm.

WARNING

Hot steam/hot coolant can escape - risk of scalding.

♦ The cooling system is under pressure when the engine is

hot.

♦ Cover filler cap on coolant expansion tank with a cloth and

open carefully to dissipate pressure.

– Open filler cap on coolant expansion tank.
– Fit cooling system tester -V.A.G 1274 B- with adapter -

V.A.G 1274/8- onto coolant expansion tank.

– Using hand pump on cooling system tester, build up a pres‐

sure of approx. 1.0 bar.

– If this pressure is not maintained, locate and rectify leaks.

Checking pressure relief valve in filler cap
– Fit cooling system tester -V.A.G 1274 B- with adapter -

V.A.G 1274/9- onto filler cap.

– Build up pressure with hand pump on cooling system tester.
• The pressure relief valve should open at a pressure of

1.4 ... 1.6 bar.

– Renew filler cap if pressure relief valve does not open as de‐

scribed.

196

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not 
 permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability 
     with respect to the correctness of information in this document. Copyright by AUDI AG.

21 – Turbocharging/supercharging

1

Turbocharger

– Observe rules for cleanliness 

⇒ page 5

 .

1.1

Diagram of vacuum connections

1 - Vacuum unit

❑ On turbocharger
❑ With position sender for

charge pressure posi‐

tioner -G581-

2 - Charge pressure control

solenoid valve -N75-
3 - Intake silencer
4 - Air cleaner housing
5 - To brake servo
6 - Connection piece

❑ On exhauster pump

7 - Non-return valve

❑ Note installation posi‐

tion

8 - Exhaust gas recirculation

cooler change-over valve -

N345-

❑ Checking change-over

function 

⇒ page 230

9 - Cylinder head cover
10 - Vacuum unit

❑ For change-over func‐

tion for exhaust gas re‐

circulation cooler

1. Turbocharger    

197

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not 
 permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability 
     with respect to the correctness of information in this document. Copyright by AUDI AG.

1.2

Turbocharger - exploded view

1 - Banjo bolt

❑ 60 Nm

2 - O-rings

❑ Renew

3 - Bolt

❑ 15 Nm

4 - Oil return pipe
5 - Nuts

❑ 20 Nm

6 - Heat shield
7 - Gasket

❑ Renew

8 - Gasket

❑ Renew

9 - Pulsation damper
10 - Bolt

❑ 10 Nm

11 - Bolt

❑ 8 Nm

12 - Bracket

❑ For electrical wiring

13 - Heat shield
14 - Turbocharger with position

sender for charge pressure po‐

sitioner -G581-

❑ Removing and installing

turbocharger

⇒ page 199

❑ Renewing position sender for charge pressure positioner -G581- 

⇒ page 202

15 - Bolt

❑ 9 Nm

16 - Oil supply pipe

❑ Check for obstructions
❑ Before installing, fill turbocharger with engine oil at connection for oil supply pipe
❑ Tightening union nuts 

⇒ Item 6 (page 151)

17 - Gasket

❑ Renew

18 - Nut

❑ 20 Nm

19 - Gasket

❑ Renew

20 - Nut

❑ 20 Nm

198