Nissan serena 2006 ,HELP! C25-119800
NISSAN SERENA (C25)

I would like to ask for your help in diagnosing the problem on this car. It’s been a few days since I arrived in NZ and bought a car. I wanted to have it checked in Akl by a mechanic before the purchase, but every service station was busy, so I trusted that the car would be fine. Because now I know it’s just bullshit. Every time after approx. 30-40 minutes of driving (depending on the terrain) the sound of the engine starts to be accompanied by something like a whine and the engine loses power and I would say that even the gearbox falls asleep with the gears. There is an automatic cvt transmission. I have already changed the oil and filters in the gearbox and the problem persists. First I drove for about an hour and then a huge hill and I had to stop and wait for it to rest. See the videos below. Local mechanics charge a lot of money and it’s hard to explain the problem to them, because it really happens after a long drive. Does anyone have any idea what it could be or what to check?

 Thank you very much for any advice and help or I will provide some information about the car

Videios with the issue