A Mercedes ML 300 CDI was brought into Auto Studio this week with an engine oil leak issue. An oil leak can come from many parts of a car’s engine and can be a tedious task to diagnose exactly where it has started if left unattended for too long.

Signs of an oil leak:

• Low oil light coming on the dashboard
• Oil spots under your car after leaving it parked
• A greasy and oily engine bay

Causes of oil leaks:

• Loose hose clamps
• Worn out seals
• Broken or blown gaskets

The cause of this oil leak was:

The leak on this Mercedes was caused due to a leaking “turbo mouth” seal, shown in Image 1. 

Image 1

This Leak then caused the mount for the turbo, which also supplies the turbo with an oil and coolant line, to help cool the turbo. A trail of oil can also be seen running down the turbo face, seen in Image 2

Image 2

This oil leak ended up getting into the motor powering the intake manifold flaps to help with emissions, causing the motor to fail, and the cars Engine Control Unit to produce a code. The motor can be seen in Image 3.

Image 3

In this instance, there was a further leak coming from the oil cooler gasket which is located in the deep in the valley.

Resolving this Oil Leak

The process of fixing this issue is mostly straight forward for the experts at Auto Studio, but it is very labour intensive as multiple components of the engine need to be removed, and seals replaced. This Mercedes was very well looked after by the Technicians at Auto Studio, and was back up and running in no time!