Volvo XC60 D4 2,4d AWD limp mode

[kaseke]

Hello all,

I have Volvo XC60 (year 2010), 2.4 diesel, D4 engine, automatic transmission, AWD.

My car has a problem with turbo / turbo boost and sitting in limp mode. The turbo is working only after the cold start up to 80 km/h and then turns off or reduces turbo boost to minimal. If the engine temperature is 90 degrees, ignition needs to be off at least ~ 10 minutes and then turbo works again but only up to 80 km/h. And then turns off again.

At first I had problem with turbo because it leaked oil. The bottom part of the engine was all oily. Same time the second problem was smoke in the engine room and sometimes it cames to the interior aswell, especially when car was parking mode with working engine. Smoke came from rear part of the engine, not from exhaust! Although my car had those problems there was not power loss or smth like that and car worked very well.
I had a guarantee from seller, so I used it and went to the seller service where they installed the new turbo (used but factory restored). Oil leak was gone but smoking remained (again, smoked from rear part of engine not exhaust!). Smoke came same place, under the bonnet, from rear part of the engine where is the turbo. I went back to the seller and their service where they did guarantee inspection works. Service was very unproffessional and first thing they uninstalled turbo and sent it to the seller for inspection. Turbo seller told later that turbo is O.K and runs very well. So, seller give the same turbo back to the performer of the works. Before the repairman started to install turbo he discovered broken plastic tube / pipe which connects two turbos with each other. New part ordered ASAP. They put engine together and give my car back. I think this broken plastic tube was the problem why sometimes came the smoke from engine room. Unfortunately they didn't see broken detail when they installed restored turbo.
If I got my car back first kilometres everything was OK, but suddenly there was not turbo boost anymore.

In the last (guarantee) service DPF filter has been cleaned and washed although I did not ordered these works. I have used my car from dec 2017 , approximately 20 000 km and I haven't had any problems with DPF-soot before.

I did diagnostics and there is no fault codes. MAP sensor is working, EGR working, turbo control valve is working. No smoke from exhaust, no smoke from engine room. I have not noticed any changes in fuel consumption.

Never had any warning lights in the dashboard.

I suspect that maybe they ruined in service DPF filter or DPF filter temperature sensor. Is it possible that DPF filter temperature sensor does not give fault code?
Any ideas?