Turbocharger K03 53039880212 CB5E6K682AB Ford Focus SCTi

Using a set of inside micrometers, measure the bearing housing pilot in the turbine housing taking two readings 90 degrees from each other. This dimension was perfectly round at the time of original manufacture. However, the turbine housing can warp and shift after extended use. What you’re looking for is how egg shaped the pilot has become. If a set of inside micrometers is not available, this can also be done using a large set of calipers. Simply find the smallest diameter point in the pilot, then use a wire-type feeler gauge to measure the gap found where the diameter is the greatest. As a general rule, you should not reuse the turbine housing if it’s egg shaped by more than approximately 0.005 inch. This is a critical measurement for two reasons. First, that area is a seal area where hot exhaust gasses under pressure are sealed to stay inside the turbine housing. Any leakages in this area will not only cause very hot and dangerous exhaust gas from leaking into the engine bay, but also it will cause a loss of turbine energy to efficiently drive the turbo. The other issue at stake here is that an extreme shift seen at this point can indicate you have a very high heat application. Further casting shift can occur and cause turbocharger failure if the turbine housing moves enough to cause housing-to-wheel contact on your new replacement cartridge.