What might cause a turbo to fail. I have had it rebuilt properly and done under a thousand miles on it at various boost levels but nothing extreme and it appears To be blown again as when I come off throttle I get a puff of blue smoke and I have play in the wheel side to side. I have always run a mocal inline filter to the turbo and I checked it and it's got no swarf inside. Oil pressure is high so and no leaks going to the turbo so I'm happy with the oil supply. Any ideas on what may have caused the failure. It's a t28 on a c1j averaging 20psi.