Sprinter oil cooler leak

Why my Mercedes-Benz Sprinter oil drip? 

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The 3.0L V6 Mercedes Diesel engine has proven to be a strong and reliable motor.  This engine is used in everything from an E-Class sedan up to the 3500 dually Sprinter vans.  The combination of power, durability and fuel economy makes this engine a superior choice everywhere it is used. The Achilles heel of this engine, unfortunately, is the oil cooler seal design.  We’ll go over the signs and symptoms plus let you know what to expect on a repair.

 

Affected Sprinters

All models that were equipped with the 3.0L V6 diesel engine, engine code OM642, can be affected by this problem.  This includes “CDI” and “BlueTEC” models alike 2006-2018 Mercedes Sprinter V6. At some point in 2010 Mercedes upgraded the seal material to Viton.  While leaks do occur in 2010+ vehicles it is less common than in pre-2010 vehicles.

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Signs & Symptoms

Failing oil cooler seals will cause the normal things you would expect from an oil leak.  This includes a “Check oil Level” or “Oil Level Low” message on the instrument cluster, decreasing oil level measurements on the oil level dipstick and leaving oil stains/puddles when parked. 

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The good news regarding this problem is that failing seals CANNOT cause oil contamination as there is no point where coolant and oil can intermix.

Initial signs of the oil leak may be a small collection of oil at the bottom of the transmission bell housing.  If you discover some wetness at that point, you should monitor the vehicle closely for increased oil loss.  Once the seals start to leak slowly the rate of the leak will increase very fast.  You may not initially get oil stains when parked as Mercedes models come with a fairly large undercarriage cover (aka belly pan) that can collect a significant amount of oil before it leaks over.

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Repair Sprinter oil leak

The repair involves replacing the two seals on the oil cooler. The oil cooler itself does not need to be replaced and can be reinstalled. When purchasing oil cooler seals always get the factory PURPLE color seals that are made of Viton. The older or aftermarket orange seals will leak much sooner.

Unfortunately, the oil cooler is located at the bottom of the middle of the engine “V” design.  It is underneath intake manifolds, EGR equipment, coolant lines, and the turbocharger.  All these items must be removed before the oil cooler can be removed.  Once those other items have been removed, physically removing the oil cooler itself and replacing the seals is very easy.

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Considering the amount of work that must go into reaching the oil cooler, repair times can vary widely, but generally, it is accepted that 10 -15 hours is a good starting point.  The oil cooler seals themselves are not very expensive (about $5 each), but there are about $200* worth of other seals for the other items that must be replaced as well so we recommend getting a full oil cooler seal kit to do the job right. 

 

Figure about $200* in parts + 10-15 hours of labor at shop-rate. 

Our Sprinter expert will help you!