Do you think that your BMW has an oil leak at the alternator seal? Having a BMW is a dream for many people who like European cars, but like any car, it needs to be maintained properly in order not to fail. If you have seen oil leakage around the area of the alternator then it could be caused by a worn out alternator seal. This may appear to be a minor problem now but it is a potential precursor to several other problems.
Why Does the Alternator Seal Leak Oil?
- Natural Wear and Tear: In the course of time, the seal of the alternator experiences high pressure, and high temperature in addition to mechanical vibrations from the engine. These conditions over time deteriorate or cause the seal’s material, which is usually rubber or synthetic, to harden, crack or wear out.
- Excessive Crankcase Pressure: The engine crankcase also produces pressure during running and is controlled by the Positive Crankcase Ventilation (PCV) system. If the PCV valve is faulty, or the vents are blocked, there is increased pressure in the crankcase. This increased pressure pushes oil through the alternator seal causing leakage.
- Engine Oil Overfill: Too much oil in an engine creates increased pressure inside the crankcase. This additional pressure puts a lot of stress on the seals throughout the engine including the alternator seal which then fails and develops an oil leakage.
- Heat Damage: The alternator is frequently mounted close to engine parts that produce a lot of heat. Prolonged working under high temperatures reduces the ability of the alternator seal material to retain its elasticity and prevent oil leakage.
- Contaminated or Degraded Oil: Failure to use the right engine oil or change it frequently opens the way for sludge, dirt and debris to accumulate. These contaminants cause friction or stress on the seal’s surface making it wear out and also leak.
Steps to Fix a Leaking Alternator Seal
- Inspect the Leak: The first step is to identify the source of the leak. With a flashlight inspect the surrounding area of the alternator for oil buildup. To verify the source of the leak ask your trusted technician to perform an extensive check for other components such as valve cover gasket or oil filter housing.
- Replace the Alternator Seal: After the source is identified, the only remedy is to replace the alternator seal. This involves the removal of the alternator, elimination of the former seal, cleaning the area where the seal is to be fitted and then fitting of a new seal. If you are a do-it-yourselfer this task is not something you should do at home. It is always better to replace it with a professional who has the equipment as well as knowledge of how to do it.
- Clean the Alternator: If oil has leaked into the alternator, it should be cleaned so that there will be no electrical problems. In some cases, the alternator will have to be rebuilt or replaced if the oil has done a lot of damage.
- Check for Related Issues: When replacing the leak, your mechanic should look at other parts that may have contributed to leakage including high oil pressure or blocked oil passage. Solving these problems will also prevent future leaks from occurring.
- Replace Engine Oil and Filter: Once the seal is set then it’s advisable to change the engine oil and the filter to ensure your BMW is running on fresh oil. This in turn helps in the smooth running and longevity of the engine.
Momentum Motorworks Is The Place To Go For Expert BMW Repairs in Birmingham
If you are faced with a situation where the 
alternator seal is leaking or if you have any doubts regarding the health of your BMW, we’re here at Momentum Motorworks in Birmingham, AL to help. We have over 20 years of experience in European car repair so your BMW will receive the attention it needs from our experts.
Our professionals are happy to assist drivers from Birmingham and other regions such as Mountain Brook, Alabaster, Hoover, Vestavia, Homewood, and Helena. We have well trained mechanics at our fully equipped auto shop to ensure that your BMW is diagnosed and repaired right so it can perform optimally for you at all times. Don’t allow a simple drip to become a full-blown problem. Come to us today to book an appointment and get your BMW back on the road in its best condition.