Problem with turbo in Y61 3.0l 2001.

[Hagalín]

I am having trouble with my turbo 3.0L y61 2001.

When I drive up the hill and at full throttle boost is 12-15 psi.
When the hill is over and I'm driving normally 90-100km/hr the boost is only 5-7psi.

I need to stop for about 2-5min turn off the car and start again then everything is fine.

What could be the problem?

[AB]

Hi mate, what exactly is the problem?

Why do you have to turn the car off after the hill?

[Hagalín]

Normally is the boost 12-15psi. After hard throttle for long time like up hills the boost will not go over 7psi on full throttle. Then when I stop the car and turn off and start again the boost start to go normal again.

I hope that this is more understandable.