The correct diagnosis of a turbocharger overhaul is very important in order to carry out the appropriate work and avoid future problems. The first blog about Centrica's overhaul order gave more insight into the diagnosis around one of the seven turbochargers. In this second part of our blog series, overhaul specialist Jeroen goes through the other diagnoses with us and looks further into assembly and inspection.

Diagnoses

After the diagnosis of the first turbo, where pieces had broken off in the turbine wheel, our overhaul specialist repeated the inspection procedure on the other six turbos. The damage to the first turbo is striking, but one of the other turbos has even worse damage.

The exhaust pipe of this turbo was found to be worn out, after which the turbo was declared defective and rejected. The costs for replacement are too high so our specialists propose a new turbo from our range.

The diagnosis of the remaining five turbochargers appears to be wear between the piston ring and the shaft. This damage is caused by carbon deposits. The shafts are then sent on to a turning shop, where the shafts are made oversize. In this way, the grooves are back within the margins again. We will order new oversized piston rings for assembly.

Centrica agreement and parts

Before our specialist Jeroen proceeds with the overhaul of the turbochargers, contact is made with the customer to discuss the expected costs and the planned work. After consultation, a decision was made not to buy a new turbo and to only continue with the overhaul of the six turbos. The turbos are intended for storage and it is not necessary to replace the old turbo with a brand new one.

After agreeing on the costs and work, our specialist will order the necessary parts for the Garrett and Schwitzer turbochargers. In the meantime, all original parts per turbo are kept together so no part will end up in another turbo. After all the necessary parts are in, Jeroen starts the overhaul of a Schwitzer turbo.

Stability control and mounting

In addition to the planned repairs and the fitting of all parts, the performance check is also a standard procedure in the overhaul. In the MasterTurbo workshop we have a balancing machine with which the vibrations and stability of the turbo are measured.

After most of the overhaul is done and the large parts are assembled, Jeroen marks different spots on the turbo for stability control of the turbo. In this way a turbocharger can be precisely identified if it is unstable, because excessive vibration is certainly not desirable for performance. After the machine has run once, the different points show how (un)stable the turbo is, after which Jeroen grinds and tightens the turbo in order to correctly adjust the part. In addition, this machine can be used to directly check whether a turbo is oil-tight and there is no leakage.

If a turbo has passed the stability test, it can go to assembly. The last parts, such as the compressor housing and the bearing housing, are reassembled on the workbench. After the test in the balancing machine, there may still be small traces of oil in the turbo for which caps are placed to prevent oil from leaking during shipment.

Ready for shipment

In order to ensure that every action surrounding our diagnoses and overhauls can be traced, all diagnoses and work are recorded in our system with a specific number. This number is marked on a plate on the turbo and on the inside of the turbo.

When the turbos are polished and the final inspection is done, they are taken to the warehouse. For each turbo our colleagues prepare the overhaul data and an assembly kit and manual, which are then packed and prepared for shipment.

In our next blog you will read more about the final destination of these turbochargers and the findings of our customer Centrica. Do you want to know more about turbocharging and our service? Our specialists will be happy to inform you about the possibilities!