I have a 97 1HZ 80 series running a turbo. I noticed a knocking sound some months ago and have found it to be a singular piston.
While the vehicle has been pulled apart the head has been reconditioned.
My mechanic has advised me only 1 piston is in bad condition, and that the rest are...
I've got a 97 80 Series 1HZ with an aftermarket turbo. The vehicle has done 289000kms.
I've noticed the vehicle has started to make a knocking sound at all times (very slightly louder when car is cold). I've had injectors removed and cleaned, valve clearance checked, shims replaced...