With Generic Scan Tool

Boost Pressure Regulation, Checking

Recommended special tools and equipment e.g.:







- V.A.G 1397 A Turbocharger Tester

Test requirements
- No leaks on intake or exhaust side.
- Engine oil temperature at least 80 degree C.

Test sequence

WARNING: To reduce the risk of accident during road tests, always observe safety precautions. Safety Precautions

Charge pressure is measured under Wide Open Throttle (WOT) while driving or on the roller type test stand.







- Using VAG1397A Turbocharger Tester test hose, connect T-piece to front of intake manifold.
- Guide test hose over rear corner of hood and through right window into vehicle interior.







- Turn turbocharger tester on and select measuring range -I- (absolute pressure).
- Connect test hose to connection flange -I-.

NOTE:
- Using turbocharger tester, see operating instructions.
- Hoses must be connected so there is no possibility of leaks, otherwise incorrect readings may result.
- Ensure test hose is not pinched at hood and side window.
- By pressing memory button "M" on turbocharger tester, the last test value is saved until either memory button "M" is pressed again or the turbocharger tester is shut-off.
- A blinking comma in display field indicates a value has been saved.
- An arrow appears in the top left corner of display field if turbocharger tester battery voltage drops below the permissible specification.
- Before testing drive vehicle rapidly at least 3 km (without frequent stops and similar).
- A second technician is required because the indicated values must be read out during vehicle operation.

- Accelerate vehicle in 3rd gear at full throttle from 2000 RPM and watch tachometer.
- At 3000 RPM press memory button "M" on VAG1397A.







- Specification on VAG1397A: 1.700 ... 1.900 bar positive pressure

NOTE: Repeat measurement if full charge pressure has not yet built up.

If boost pressure is exceeded:
- Check Wastegate Bypass Regulator Valve -N75-. (Throughput in hose from turbocharger via valve to vacuum diaphragm with connector disconnected)
- Check for proper seating of vacuum diaphragm for wastegate bypass regulator valve at turbocharger.
- Check vacuum diaphragm Vacuum Diaphragm For Wastegate Bypass Regulator Valve, Checking
- Check bearing for shaft of wastegate bypass regulator valve in turbocharger for ease of movement. If rusted solid, replace turbocharger.

If boost pressure is not reached:
- Check Wastegate Bypass Regulator Valve - N75-.
- Check bearing for shaft of wastegate bypass regulator valve in turbocharger for ease of movement. If rusted solid, replace turbocharger.
- Turbocharger faulty, replace.