Ok :-) Last time I changed the gear oil I also add a product called "QMI" its a kind of oil additive. Maybe this wasn't so smart....

I have never cleaned the intercooler, the car has run about 260000km I will try to clean it in the start of january, also check the turbo pipes, MAP pipes etc.

Could you explain this procedure again? I am not sure I understand it

Yes i am using ATF , dexronIII

I changed the gear oil and filter at 30000km ago, the problem started 10000km after the oil/filter where changed.

Hello, the consumptions is not at town driving, only at run. In town driving the consumptions is about 16mpg (14.7 L/100km)

I have a -98 mod 2.5DSE with high diesel consumption about 19mgp (12.5L/100km). A year ago the consumptions was normal (26mgp or 9L/100km), but suddenly it start to use more fuel and the torque was also less. The car has been in 2 kinds of garages but they can’t find anything wrong, no error...