turbo going into limp mode

[hawheed]

had this problem in 3rd gear when under acceleration, the turbo would go into limp mode

now had a mechanic look at it and it seemed to be the wastegate wasnt opening far enough, quick spray of wd40 and off it went, no problems in 3rd gear when accelerating, now after a few months the problem has now went to 4th + 5th gear when i hit about 2200 rpm. if i dip the clutch and cut off the engine and fire it up again it seems to reset itself

btw the car is a passat 1.9tdi 110bhp

[martin1810]

A code read is the best place to start.

[Izalman]

I dont believe there is a wastgate on the tdi engines, key to the problem is turning engine off & restarting. This is resetting the ECU that contols boost / fuel etc.
Suggest you replace the MAP ( manifold absolute pressure sensor) this measures boost pressure & temp feeding data into ecu, if it goes **** up sendscduff info to ECU = limp mode for engine protection.
Best get part from VW - they call it the thrust sensor, I paid £45 inc VAT - 5 minute job to fit with pozi screwdriver

[PeteK]

As above, there is no wastegate. It sounds more like the variable geometry turbo vains are sticking, the actuator can be seen on top of the turbo. However as also has been said, get a fault code check before randomly replacing parts as it could be a different fault to what you had last time.