How much does it cost to repair a Mercedes Benz Oil leak?

This blog will answer the following questions: how much does it cost to repair a Mercedes Benz Oil leak? What are the different types of oil leaks in Mercedes Benz cars? How to check if there is an oil leak in your Mercedes Benz?

How much does it cost to repair a Mercedes Benz Oil leak?

It can cost 500 to 1000 USD to repair a Mercedes Benz Oil leak. The cost of repairs includes spare parts cost and the Labour associated with the repair work. Oil leaks in Mercedes Benz occur due to a damaged gasket, improper sealant between the parts of the engine and accidental impact on the engine oil pan.

What are the different types of oil leaks and their remedies in Mercedes Benz cars?

The different types of oil leaks in Mercedes Benz Cars are listed below:

External engine oil leak:

  • Engine oil leaks from the oil filter body
  • Engine oil leak from cylinder head cover
  • Engine oil leaks from the oil pan

Internal engine oil leak:

  • Engine oil leaks from the oil cooler
  • Engine oil leak from valve stem seals

All external engine oil leaks are visible to the naked eye and easy to identify, let’s take a look at each type of external oil leak in detail.

  • Engine oil leaks from the oil filter body

All Mercedes Benz engines consist of an engine oil filter body located on the crankcase. The oil filter body houses an engine oil filter, non-return valves and engine oil coolers. It is bolted on the engine and rubber O- rings are used to seal the contact surfaces between the oil filter body and engine crankcase

The rubber O-rings between the oil filter body and crankcase are under extreme amounts of pressure and temperature due to the heat from the engine. Over time, the rubber seals get weak and start to seep engine oil.

The engine oil sweating from the weak O-rings is not identified easily as the oil filter body is located very near the engine block. When the O- ring completely fails, the engine oil can leak in more quantity as the oil pressure is 4- 7 bars.

The remedy is to replace the oil filter body O-rings and then re-install the oil filter body. This type of oil leak is only common on vehicles with high mileage. The repair cost of the spare parts is not expensive, but as the oil filter body must be removed to replace the O-rings, the labour cost can be from 200 to 500 USD.

  • Engine oil leak from cylinder head cover

Mercedes Benz engines have overhead camshafts that are mounted partially between the cylinder head and the cylinder head cover. The cylinder head cover is bolted on the cylinder head and depending on the engine there can be a rubber gasket or a high-temperature resistant sealant between them.

The diesel engine uses rubber gaskets with a plastic cylinder head cover as the camshafts are housed inside a separate bridge. The petrol engines use sealants as the cylinder head cover is made up of aluminium.

In both engines, the sealant or the gasket must be renewed to rectify the oil leak. Replacing the sealant on the petrol engine can take more time as the old sealant must be cleaned. The engine also cannot be started until the fresh sealant is completely dried.

  • Engine oil leaks from the oil pan

The engine oil gets collected in the engine oil pan when the engine is not running. The latest Mercedes Benz models have engines with the plastic oil pan. There is a rubber gasket between the plastic oil pan and the upper section of the engine oil pan. If there are leaks, then the engine oil pan must be removed to replace the oil pan gasket.

The plastic oil pan is protected by an underbody metal shield. However, the shield can get deformed by an accidental impact and damage the oil pan. In such cases, the oil pan cannot be repaired and must be replaced. If the vehicle is insured the insurance company can cover the costs of spare parts and repairs. 

An internal engine oil leak can happen when the engine oil is entering the combustion chamber or one of the engine oil coolers has a leak. Both the types of internal engine oil leaks are discussed in-depth below:

  • Engine oil leaked from the oil cooler.

Mercedes Benz engines use a liquid-cooled engine oil cooler to cool the engine oil. The operating temperature of the engine oil is crucial as it can affect its viscosity and other properties. Therefore, the engine oil cooler is located near the engine block.

Due to the extreme heat and the corrosion in the coolant system, the heat exchanger gets damaged and engine oil mixes with the coolant. The level of engine oil goes down as it enters the cooling system and contaminates the coolant.

The remedy is to replace the engine oil cooler and also drain the complete coolant system. The coolant and any coolant hoses that are deformed due to the engine oil are renewed after replacing the oil cooler.

  • Engine oil leak from valve stem seals

All the latest engines have 4 valves per cylinder and the valve stem seals are used to seal the area between the combustion chamber and valve train. The valve train is completely submerged in engine oil and when the engine is running, a leaking valve stem seal will allow engine oil to enter the combustion chamber. The engine oil gets combusted with the air-fuel mixture leaving behind excessive carbon deposits.

The remedy is to replace all the valves and the valve stem seals, while installing new stem seals a special sleeve is used so that the valve lock grooves do not damage the seal. The complete job is time-consuming as the complete cylinder head must be removed from the engine to replace the valve stem seals.

How to check if there is an oil leak in your Mercedes Benz?

If there is an external engine oil leak then check the parking spot of the vehicle. If there are oil marks on the floor then it is possibly due to an external engine oil leak. 

Internal engine oil leaks are harder to check as no oil leaks outside the engine. It is either consumed or mixed in the coolant circuit. Checking the engine oil level is the only way to identify if there is an internal engine oil leak.

Consult the nearest authorised dealership if the oil pressure light is active or if there is a frequent top-up engine oil level message in the instrument cluster.

Other articles about Mercedes Benz you may be interested in

Is your Mercedes speaker crackling?

How is the Mercedes Benz C Class compared to the Mercedes Benz S Class?

Mercedes Benz E Class Vs Mercedes Benz S Class: the ultimate comparison

Conclusion

This blog explained the different types of oil leaks in Mercedes Benz cars and the possible remedies to rectify the oil leaks. The repair cost of oil leaks is high due to the complexity of the engine and the high labour rate required for the repair job.

What was missing from this post which could have made it better?

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