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GT3540/76 Oil Starvation Failure Analysis Through my vast experience in Turbocharger modification and servicing, I have come across my fair share of failures, from minor noisy bearing failures to completely nuked turbochargers. A good 80% of them are oil related, especially when it comes to GT3540/GT3576 Falcon series turbochargers through oil feed line filter blockages and dirty oil supplies. We're going to breakdown various parts of a blown turbo (GT3540) to analyse and identify parts that are damaged, worn and brand new. A similar process that we follow at RaceEquipped. This turbocharger is a extreme case, as it is completely NUKED in every way and form. When disassembled we found ONE remaining ball bearing within the cage (Most Garrett ball bearing turbos have 14-16 balls within the casing) safe to say they all are sitting at the bottom of someone's sump. Bearing Casing The bearing casing is the first point of contact for bearing health when disassembled. From Left to right, we have a Brand New Casing, Used casing, Used casing passed its service schedule, and last is a nuked turbo bearing casing. The colour change from the shiny new to a dark colour is vanished oil, the ideal used bearing casing is the second from the left, this vehicle has kept oil and filter changes regular. Other variables are also involved in oil varnishing from Exhaust temps to Oil grades and thicknesses. The last casing has been nuked, the bearing race has melted and no longer exists. Bearing Cage The bearing cage which holds the balls that rotate within the casing can show signs of wear also, being made from plastic they don’t like high temperatures & lack of oil. Here we can see what used to be a yellow bearing cage that has been cooked and warped. These bearing cages can also be ripped to shreds. Bearing cage and the bearing race health are consistent with the amount of“shaft play. Exhaust Seal Seats Now exhaust seal wear is inevitable, and we opt to NEVER reuse them even if they look healthy. But the seats for the seals in the CHRA can be damaged through excess bearing wear, or catastrophic failure, here we demonstrate the difference between a used CHRA and a sheared exhaust seal seat through the ring gap. Internal Inspection These photos speak for themselves, this side of the CHRA is prone to oil vanishing and is hard to avoid as it has no direct constant oil feed to offset the oil sitting to bake. In this case one is clean and one has shavings all through it, and chunks of bearings, bearing casings and what ever else has been sheared off. Turbine Shaft Inspection As above, exhaust seal wear is inevitable, in some cases the seal can fuse to the shaft through excess exhaust temps or oil starvation. Bluing of the turbine shaft also results from excess heat through in rare cases tuning, but is generally consistent with oil starvation. Here shows a used turbine and our nuked GT3540 Turbine where the whole lower section is fused and is unrecognisable. Conclusion These are a few of the following processes in our turbo health inspection test that is part of our rebuilds. In conclusion oil plays a MAJOR role in turbocharger health, to avoid these issues it must be recognized that the importance of Regular Oil & Filter Changes in ALL turbocharged vehicles. Im especially fussy on this, that ALL turbocharged vehicles should be serviced every 5000KM. The Ford Falcon Oil feed line oil filter MUST and SHOULD be replaced with a genuine item every service interval. A oil feed filter is a great assurance against dirty oil supplies, but can be a double edged knife in the sense that it can also be the demise of your turbo if not properly maintained. 99.9% of after market turbochargers that require the removal of the factory oil line filter is using a after-market bush bearing core. In essence a Failure to do the above steps can and will cause oil starvation and can extend the life of your turbo. - Nick