Puzzle at 3,500 RPM in 4th Audi TDi

[bjw970s]

Had a B5 1.9 TDi for about 5 months and have discovered a puzzling fault. When you accelerate in 4th gear and pass 3,500 revs you can feel a drop off in power as if the turbo has been switched off.

Car still drives but has lost that TDi acceleration. Stop, switch it off and the turbo magically comes back.

Only seems to happen in 4th gear :confused:

Anyone else come across this?

Any pointers welcome

[ini]

Check your Mass Airflow Meter, this is the most common cause of 3000rpm power loss in higher gears.

It most likely needs cleaning or replacing.

[Crasher]

Have it fault code read and you will probably see the code.

"17965 - Charge Pressure Control: Positive Deviation
P1557 - 35-10 - - - Intermittent"

If that code is present, then the two most likely causes are jammed turbo vanes or a sticking/over reading MAP (Manifold Absolute Pressure) sensor.