Q
TURBO FAILURE: Why do turbos fail early?
A
Partly due to the oil feed to the turbo getting blocked by oil sludge due to insufficiently frequent oil changes.
And partly due to owners failing to idle turbos from red hot before switching off. If they don't let the engine idle for a minute or two while the turbo rotor spools down, thus pumping fresh oil through the turbo bearings, the oil in the bearings can carbonise and the bearings effectively run unlubricated.
Turbos get red hot after sustained high performace driving (especially 'track days'), after sustained high speed on a motorway, after driving up a long incline (especially at low speed), and after towing.
Driving on the level for 5 minutes at low rpm has the same effect in helping the turbo cool down as idling it, so idling is not always necessary.
