Low Engine Power 3lt Diesel

[Tonner61]

Hi guys looking at purchasing a 98 Hilux tray back ute for my son, it has a 5l Diesel with 311k on the clock, aftermarket turbo fitted. The car is in good nick but recently suffered a sudden power loss. Sounds ok, no smoke, starts and runs ok just wouldn't pull the skin off a custard. So the question is what is most likely the issue ? Turbo, injectors or pump? Is it worth the risk at 3k for the vehicle. Appreciate any advice

[Steven]

Sounds like a problem with the turbo, which if it wasn't boosting or spinning the compressor wheel properly would act more like a major restriction on the inlet thus limiting power substantially