Broken revision 3 Toyota MR2 turbocharger - CT20B






Exhaust turbine wheel snapped off at 57 thousand miles. For 6 months there had been a slight whine when at low speed when using the throttle slightly; sounded just like a whine from a differential, but everything worked fine even under sustained wide open throttle. Then one evening the whine became a loud raspy noise, and as soon as the engine warmed up enough for me to open the throttle up half properly, the thing exploded - and the whine I'd had for 6 months had gone... unfortunately so had all the power above 4000 RPM.

The mileage sounds low, but I use the turbo an aweful lot, so the 57k seems probably about the equivalent of the 75K Turbo Technic's site reckons a turbo typical lasts. There was no oil leaks I could notice, just radial play in the bearing, but theres also radial play in a brand new one, the limit in the manual is 5 thousands of an inch, which is quite a bit. There was no axial play I could feel. Interestingly, 4000 miles before the turbo failed, I had to tighten the nuts that held the turbo onto the exhaust manifold as they had all vibrated loose.



http://www.mr2turbo.info/