On my K14 turbo, I can move the inlet turbine radially about 0.010 in. I'm guessing this can't be good.
Some radial play is normal. Turbo bearings "float" in oil both at the shaft/bearing interface and at the bearing/housing interface as well. The oil cushion allows the shaft to run off centre or wobble if needed to accomodate rotor imbalance. As long as the wheels don't touch the housing the turbo is usually OK.
Axial (in and out) play is another matter, there should be very little, a few thousanths of an inch at most.
Some radial play is normal. Turbo bearings "float" in oil both at the shaft/bearing interface and at the bearing/housing interface as well. The oil cushion allows the shaft to run off centre or wobble if needed to accomodate rotor imbalance. As long as the wheels don't touch the housing the turbo is usually OK.
Axial (in and out) play is another matter, there should be very little, a few thousanths of an inch at most.
There's no noticable axial play. Thank you for the help.
The K14s are such small shaft turbos with bearings very close together, that even brand new them seem to have considerable play. As said, as long as you can't get the wheels to touch the housing you're pretty much okay (until they do touch and grenade, tossing shrapnel into your intake- another good reason to have an intercooler :wink: )
Andrew
I figured something spinning that fast couldn't tolerate any radial play whatsoever. Good to know some play is normal. The car has 127,000 miles and the previous owner changed the oil every 2,500 miles with Shell Rotella. It shows. The inside of the engine is spotless. An intercooler is part of the planned upgrades -- Blackstone from a Saab 900. Thank you.