My dad said today, while driving, the power suddenly cut off and he could only rev to about 2500 rpm and no more. After this i did some digging around. Some suggested it's the hosses collapsing, some said clogged intercooler, some said exhaust and some suggested serviciing the turbo. So i let my dad know on these and a little while ago i got the report.
Both intercooler hoses are collapsing for some reason. He has run the engine without the air filter and it produces the same result. Also mentioned that hoses are soft & mellow.
Turbo unit was serviced recently. Also my dad had done something to the hoses to reinforce them and said the hoses are still collapsing but not as much as before.