In the previous part of this series you learned more about blockages and seizures. Part 2 deals with the defects surrounding leaks and the associated symptoms, causes and consequences of these problems. Our specialists are happy to explain how to prevent these leaks and discuss a common case of a BMW diesel.

Leakage symptoms

Various leaks can occur at the turbo, such as exhaust gas, coolant, oil, vacuum or pressure (actuator). An oil leak is most common and is immediately visible. This is usually caused by dirty oil, which wears out the bearings, the rod and the seals. In addition, exhaust gas leaks are also common due to particulate filter problems.

In normal operation the turbo never leaks so it is important to fix the defect as soon as possible. The diagram below may help you identify the location of your leakage problem.

In addition it is sometimes the question of whether there is a leak around the turbo or the engine block. It is important to find the location of the problem and to solve it, for example in the case of cracks in a hose. If a leaking turbo is only replaced without solving the cause of the problem, this can lead to more problems and repairs in the future.

Many of these leakage problems can be solved by tightening or replacing bolts, replacing gaskets and/or checking and solving blockages and seizures. A clogged catalytic converter or particulate filter can be the cause of a leaking exhaust.

We can diagnose the problem for you and in most cases solve the leakage through a repair and overhaul.

Leakage defect in the workshop

MasterTurbo will be happy to help you with specific advice and expertise regarding these repairs. Upon arrival at our workshop, the customer's complaints are looked at and leakage points are investigated.

In our workshop, for example, we see a recurring complaint about a turbo failure with the electronic actuator of a BMW diesel. During the examination, traces of leaking oil can be seen on the exhaust side, traces of soot can be seen around the VNT lever and axial play can also be felt.

During disassembly our specialists see that the particulate filter is clogged, causing the exhaust gas pressure to rise and the turbo shaft to be continuously pushed towards the intake side. The oil film between the turbo shaft and the thrust bearing is pushed aside and loses its effect, eating away at a metal disc in the thrust bearing. In time this will result in wear of the compressor wheel and the turbine wheel. As a result, pieces of the turbine wheel can also enter the VNT turbo, causing the turbo to seize and the electronic actuator to malfunction.

Further investigation shows that these customers have two thermostats in the engine block: one for heating the interior of the car and one for regulating the heat of the engine. The last thermostat is open, keeping the engine temperature at 70 degrees Celsius. However, the cooling water must be at 90 degrees Celsius to start the regeneration process of the particulate filter, which means that the particulate filter is now clogging up and causing high exhaust gas pressure.

As a solution to this problem, the broken turbo and defective thermostat must be replaced together with a new oil and air filter. Cleaning or replacing the particulate filter is also necessary.

Preventing leaks

Leaks can cause major damage to your turbo and even your engine block. Continuing to drive with a leaking turbo, as in the previous example, can result in high repair costs and even a complete turbo replacement.

On-time and proper maintenance is the most important thing to prevent a turbo defect. This results in fewer blockages, which also reduces the risk of leakage. It is very important to respect the oil replacement times, because oil is the most important thing for a well-functioning turbo. If oil changes are not done at the recommended times, this can cause major damage to the bearings of your turbo.

Good gaskets, O-rings and bolts are also important when installing your turbo. A turbo works under high temperatures and speeds, which makes a suitable high-quality seal important. Our specialists also provide advice here and can supply spare parts where necessary.

The above mentioned defects, symptoms, causes and solutions can also be found in our troubleshooting table. You can obviously also send an e-mail to our specialists for personal and specific advice.

In the next part of this series you will learn more about the symptoms, causes, consequences and required work on defective or damaged turbo parts.