What Can Go Wrong in Your BMW’s Transmission System?

Without a working transmission, your BMW won’t have the ability to propel itself as designed. The transmission is needed to convert energy created by the engine into torque. This torque makes your wheels turn and also allows gear changes. Put simply, the transmission is the connection between your engine and your wheels.

Like your engine, the transmission system should last the entire lifespan of your vehicle, but it does need proper maintenance. You should practice routine service for your transmission fluid, just like engine oil. Problems with the transmission fluid are actually the leading cause of transmission failure, but more on that later. Let’s first take a look at how you can tell if your BMW has transmission issues.

Common Signs of BMW Transmission Issues

• transmission becomes stuck in one gear or refuses to shift to certain gears
• frequent gear slipping
• noisy when in neutral
• transmission malfunction message
• hard transmission shifts instead of smooth ones
• gear changes are erratic and may bump in one or more of the gears
• the engine revs but doesn’t shift
• lag when switching gears
• check engine light illumination
• fault codes
• transmission or engine overheating

Things that Can go Wrong in BMW Transmission

There are many reasons why your BMW’s transmission might develop issues, but there are three main causes that are more common than others. Let’s explore these further:

Transmission Fluid is Low

The transmission system needs fluid to keep it well-lubricated and to help to reduce the high temperatures produced when changing gears. Transmission fluid can run low either because there is a leak or because it has reached the end of its lifespan. You should make sure to refill your transmission fluid as needed, checking it at least every six months to ensure the reservoir is full.

Leaks in your Transmission

There are a variety of seals and gaskets which are used to keep transmission fluid inside the transmission system. As your vehicle ages, these seals and gaskets can start to fail, leading to a transmission fluid leak. While the leak is sometimes internal, oftentimes transmission leaks will show externally as droplets on the ground below your car. Transmission fluid is dark red or pink and smells a little sweet. It will tend to pool under the front of your BMW.

Blocked Transmission Fluid Filter

As the transmission fluid circulates through the transmission system, it can collect dirt and grime. Because of this, your BMW’s transmission system has a filter to catch the debris. This helps to keep the transmission system clean. When it reaches the end of its lifespan, the transmission fluid filter gets clogged. This prevents transmission fluid from passing through and will cause a similar scenario as when your transmission fluid is low, despite actually having enough fluid inside the system.

Mechatronic Bridge Seal Adapter

One fault which tends to affect the transmission of BMW vehicles is the failure of the mechatronic bridge seal adapter. This component is needed to prevent pressure loss within the transmission system, which allows for smoother gear shifting.

In BMWs, the plastic adapter can crack, which causes a fluid leak and reduces pressure output of the mechatronic valve. This results in transmission issues and erratic gear changes.

The following BMW models are most susceptible to mechatronic bridge seal adapter failure. Drivers of these cars may want to pay particular attention to warning signs and also make sure their transmission is properly maintained:

• 2001-2008 BMW E65/E66 7 Series
• 2004-2006 BMW E53 X5 V8
• 2003-2010 BMW E60 5 Series
• 2005-2011 BMW E90 3 Series
• 2003-2010 BMW E63/E64 6 Series
• 2007-2013 BMW E70 X5 Excluding the 4.0d
• 2008-2012 BMW F01/02 7 Series Excluding the 760i/Li and Hybrid 7

Trust Ultimate Bimmer Service

As our name might suggest, at Ultimate Bimmer Service, we pride ourselves upon giving your BMW the ultimate all-round care package. We’re easily accessible for BMW drivers of the Carrolton and Dallas, TX communities to receive the very best in superior automotive maintenance and repairs. Call us today to schedule a convenient appointment with our experts.