What a turbocharger is made of
A turbocharger has a turbine wheel driven by exhaust gas, a compressor wheel on the same shaft, bearings that support that shaft, and casings that guide the gas and air. The shaft, wheels and bearings together form the rotating assembly. Many people call it the cartridge or the core, although the terminology and the construction vary between manufacturers and designs.
What a cartridge exchange involves
In a cartridge exchange, the rotating assembly is removed and replaced as a unit, while the casings generally stay in place on the engine. Because much of the work is a swap rather than a repair, it is often considered when time alongside is limited. The exact procedure depends on the make, model and installation.
A few points deserve attention. The replacement assembly must match the turbocharger type and should be balanced and documented. The removed assembly can also show what went wrong, so it is worth keeping it for inspection. The casings, connections and oil supply still need to be checked, because a new assembly will not last if the original cause of the problem is still present.
What a full overhaul involves
An overhaul usually means dismantling the unit, cleaning and inspecting every component, comparing the measurements with the manufacturer's data, reconditioning or replacing worn parts, balancing the rotating assembly and testing it before delivery. This is the same sequence described on our Workshop & Recondition service: dismantle and inspect, recondition worn components, balance and test.
The main differences
- Scope. An exchange concerns the rotating assembly. An overhaul looks at the whole unit.
- Time. An exchange can be quicker on board, provided a matching assembly is available. An overhaul takes workshop time.
- Inspection depth. An overhaul gives a full picture of every component. An exchange gives less information about the parts that stay on the engine.
- Parts availability. An exchange depends on a suitable replacement assembly. An overhaul depends on the parts needed to recondition the existing one.
- Cost. This depends on the unit, its condition and the parts involved, so it can only be discussed once the details are known.
How to choose
These questions usually guide the decision:
- What is the condition and operating history of the unit?
- What caused the problem, and has the cause been dealt with?
- Are the casings and the other components in good condition?
- How much time does the vessel have?
- Is a matching replacement assembly available?
Always follow the manufacturer's recommendations and any class or owner requirements that apply. If you are unsure, an inspection is the safest way to find out what the unit needs.
Next step
Send us the turbocharger make, model and serial number, a photo of the nameplate and a short description of the issue. We will tell you what we can do and what we still need to know. If you want to understand the possible causes first, read about marine turbocharger failure causes.
This article is general information and not a substitute for the manufacturer's instructions or an inspection of your unit.