If you are blessed to drive a Bentley, the most important factor you should consider is to commit to doing periodic maintenance & repair which is vital to ensure your Bentley runs in optimum condition. When your Bentley doesn’t perform the way it used to, because of the so-called signature defects or from common problems caused by missing out the routine maintenance, you will need a specialized service center that you can trust to fix these issues. Turbocharger oil leakages and other defects are very common in high-performance vehicles due to their highly demanding output requirements. Very recently we received a Bentley continental with a serious problem of heavy oil leakage to exhaust pipe and inlet manifold area. Large traces of engine oil were found in air filter & housing area. On a detailed inspection, we found out that bank two turbocharger was defective which caused the problem.

Usually, turbocharger replacement is a costly affair, the brand name BENTLEY makes it costlier. The turbocharger in this vehicle could cost, approximately, 12K to 15K. Our experts in the service center removed the turbocharger dismantled it and found it with some damaged components. The condition of the unit was in such a way that most service providers will recommend only replacement of the whole unit. But our team suggested the client a cost-effective solution and given the confidence for overhauling of turbo unit instead of replacing it which will save a lot of money for him.

On a very base level, the turbocharger consists of a turbine and a compressor on a common shaft with bearing and thrust support bushings. The turbine shaft could be rotating at a very high speed of 100,000 revolutions per minute. Both the compressor end & turbine end is sealed from each other to prevent lubricating oil leakage. The amount of heat, high RPM operation, etc. makes turbocharges extremely difficult to repair and only very few experts are available in UAE. We are proud to say that one of them happened to be us!

The sealing on the compressor end is more complex than the sealing on the turbine end, because of the low pressures that sometimes occur in the compressor housing. Some of the reasons causing these low pressures are air slipstreams occur between the compressor housing and compressor impeller backplate, the pressure drop occurring through the air filter, and the low-pressure regime occurring at the compressor during non-boost periods when the engine operates at low or idling speeds. These low pressures cause a vacuum behind the compressor impeller and there is a trend for oil to be sucked from the bearing housing into the compressor housing. This leaked oil then flows through the compressor impeller towards the engine cylinders where it is burned. Over a period, the time when oil contaminations are high or failure to comply with the recommended oil replacement intervals, given by the manufacturer, results in deterioration of the oil structure, Besides, sludge formation at the internal surfaces of the oil supply pipes, as well as at the circumferential holes of bush bearings. This is more pronounced on the turbine side because of the hot exhaust environment and leads to the reduction of the pipe diameter that is equivalent to an oil flow reduction occurring in the turbocharger which eventually leads to a system failure and oil leaking to the inlet air supply and exhaust side of the vehicle.

Overhauling of Turbocharger deserves a high quality and precision job right from dismantling. Soon after we dismantled the turbocharger assy a very detailed inspection was performed. The lubrication lines were partially blocked due to the excess plague buildup of cooked carbon in the high temperature of exhaust gases. All components were cleaned and inspected carefully and took the measurement of inside housing diameters and outside shaft diameters helped us to determine which parts can be reused and which need replacement. All the bushing and thrust bearings and seals were replaced and we reached the most difficult step of rebuilding the turbocharger which is balancing. The compressor and turbine wheels were balanced individually and then the entire assembly was balanced. Even the slightest imbalance could ruin everything that we did. Soon after we completed the balancing the turbocharger cartridge is assembled with new bearings and seals. The shaft spins on a thin layer of oil just like the crankshaft in an engine. Worn bearings cause excessive shaft play. Oil can escape past the seals. Clouds of blue smoke from the exhaust pipe on boost could explain where all that oil is going. After hours of hard work finally, the turbocharger was ready for installing on the vehicle again for a million kilometers of a journey without any breakdowns or interruptions!!!!!!

If you need to know more about turbochargers repairs or any other mechanical related services, visit us website or call us at 054 996 8446 (Abu Dhabi) & 054 996 8419 (Dubai). We will be happy to help you.