Welcome to our BMW and MINI tech blog!
There are more than 1,000 Q&As and DIY guides posted here. Feel free to search by keyword (upper right), browse by category (lower right), or watch one of our helpful videos. Once you've found the answer to your question, you can get the parts you need in our online store – www.BavAuto.com.
A common oil leak on late model BMW 6-cylinder engines is the small gasket between the oil filter housing and the engine block, known as the oil filter housing gasket (or, OFHG). The oil filter housing is the large aluminum casting that houses the oil filter and also mounts the alternator and the power steering pump. This issue apples to the M50, M52, M52TU, M54, M56, S50, S52 and S54 6-cylinder engines from the early ’90s through the late ’00s. With this noted, the most common models for leakage are the M52TU and M54 versions. On these engines, it’s not a question of IF the gasket will leak, but WHEN. The cure is to remove the housing and replace the gasket. And, once the work has been done to replace the gasket, it’s not uncommon for it to begin leaking again. Of course, this can be rather frustrating. While the gasket is only a few dollars, the labor to replace it is not inconsequential.
Knowing the problems with the standard replacement gaskets, BavAuto has worked with our suppliers to develop a new long-life oil filter housing gasket that is made from Dupont’s high-tech Viton material. Viton is far more resistant to the heat and chemicals associated with the oil filter housing gasket. Installing the BavAuto Viton gasket means this will be the LAST time you perform this task.
“So, it shakes a little bit when I hit a bump. Big deal …….”
Well, in fact, this really can be a big deal. Many vehicle owners tend to push suspension parts past the point of degraded function, simply because the car still drives and it seems to handle fine …. most of the time. That is, until it hits a bump in the pavement or goes past a certain speed. Then, things get a bit iffy ….. ehh, but it calms back down and on they go.
As a vehicle’s suspension ages and wears, the moving parts become loose and no longer closely control the movement of the wheels. This can show up as vibrations at various speeds, shaking while braking, oscillations when going over bumps and even changes in the vehicle stability and direction of travel.
So, what wears in a BMW or MINI suspension system? Typically, we’ll have bushings where control arms pivot, ball-joints where control arms connect to the wheel spindle (or, hub) assemblies, rubber mounting points for shock absorbers and the shock absorbers (or, struts, as many like to call them – at the front) themselves. As these parts wear, they allow the suspension components to move around more than the design parameters intend. The parts (especially rubber mounts and bushings and the shock absorbers) may not show visual signs of failure, but they are in a degraded wear stage that does allow excessive movement of control arms and wheel hubs (and, hence, the wheels). This can lead to dangerous shake and shudder in the suspension when traversing rough pavement or bumps. The shake/shudder can be severe enough that the vehicle becomes unsettled and unstable, affecting braking and steering …. maybe at a time when close control is specifically needed! For example; the vehicle braking distance will increase substantially if the wheels are bouncing or shaking on the pavement. We have even driven vehicles that would move left or right in the lane when hitting bumps. As you can see, worn suspension components have their own hidden dangers that may not be apparent in a visual inspection.
Take care of worn suspension parts as soon as they become apparent.
Ok, but how do I know they are worn if an inspection may not catch them?
Be aware of how your BMW or MINI drives. You, as the main driver, are the best source of knowing when something is different. If you notice that the front or rear wheels (suspension) are shaking or bouncing more than “normal”, especially when running over rough pavement or bumps, this is likely an indication that the suspension bushings and/or shocks are worn to a point that they should be renewed. The suspension should feel firm and well-planted when traversing rough surfaces and bumps, anything else is an indication of worn components.
Check out the BavAuto online store at www.BavAuto.com to explore the suspension bushings, mounts, control arms and shocks (struts) for your BMW or MINI … or … give our Advisors a call at 800-535-2002 for assistance in determining what you may need.
The alternators in our vehicles are high powered electrical generating stations that are capable of supplying power levels that required a building sized “dynamo” back in the early days of electrical generation.
Today’s vehicle alternators must contend with high heat, high RPM operation and high power draw demands. In fact, our BMWs and MINIs are quite power hungry with all of the electronics to satisfy both governmental and user demands and features.
We’ve all had an alternator fail on one of our vehicles if we keep them long enough; be it a BMW, MINI or other marque. We’ve come to expect these eventual failures and accept them in due course. But, can we do anything to assure the longest life possible from our alternators?
The alternator’s common failure modes include:
* Rectifier diode failure - The alternator produces AC voltage (Alternating Current, just like you use at home … thank you, Mr. Tesla & Mr. Westinghouse), which is then converted to DC voltage (Direct Current … Thank Mr. Edison for developing DC electricity) by a circuit known as a diode bridge rectifier. High heat can damage the diodes in the rectifier circuit resulting in a reduction or loss of the DC voltage output or damaging leakage of AC voltage into the vehicle’s systems.
* Bearing failure - The alternator core (armature) spins within the housing via two bearings (one at each end). The bearings can wear and rattle or squeal with age, or seize, resulting in the alternator not spinning.
* Voltage regulator failure - The alternator circuitry incorporates a voltage regulator that adjusts the voltage output to match the vehicle electrical load requirements as well as the battery’s charging needs. A failed voltage regulator can lead to insufficient electrical supply for the vehicle systems resulting in shut down of various systems or the complete vehicle. Additionally, the battery can be under charged or over charged, permanently damaging the battery.
What can we do to help prevent premature alternator failure?
Heat is the number one killer of an alternator. Excessive heat can damage the alternator’s diodes as well as the voltage regulator and even the bearings. Excessive heat can be due to numerous issues, to include:
* Broken alternator air cooling ducts - Many BMWs and MINIs have air cooled alternators. Broken or missing air cooling ducts will cause the alternator to run at higher temperatures.
* Engine overheating - If not air cooled, the later model BMWs and MINIs will have liquid cooled alternators. These systems use the engine coolant to cool the alternator. Engine cooling system problems that result in consistent higher engine temperatures will also cause the alternator to run hotter than desired. Additionally, the higher under-hood temperatures will overheat the alternator, be it liquid or air cooled.
* Short driving trips - Short driving times can stress the alternator by consistently requiring high alternator output, which makes the alternator run hotter. Ultimately, resulting in heat failure. In short trips the alternator does not have enough running time to replace the energy that has been drawn from the battery during the period that the vehicle has not been running and during the starting phase, all while supplying the normal energy required for the running vehicle. This puts the alternator in a constant high-output mode …. creating high heat. This scenario is multiplied when the short trips also employ high vehicle electrical demands, such as; headlight use, climate control blower use, rear defroster use, heated seat use, etc.
* Degraded Battery - A battery that does not hold a full and proper charge will require the alternator to run at higher output levels (similar to the short trip points, above), resulting in consistent higher operating temperatures.
* High RPM - An engine that is frequently run at higher RPMs will also spin the alternator at higher RPMs. This generates more heat as well as accelerates wear on the bearings.
While the alternator is not a “lifetime” unit and can be expected to eventually need replacement, paying attention to the points noted above can help to extend the life of your BMW’s or MINI’s alternator.
* Fix any damaged or disconnected air cooling ducts.
* Take care of engine cooling system issues right away.
* Use a trickle charger if short trips with high power demands are a part of your BMW’s or MINI’s typical use.
* Replace the vehicle battery at the first signs of age (low voltage, losing charge while idle, etc.).
Check out the BavAuto online store at www.BavAuto.com or give your Advisor, at BavAuto, a call at 800-535-2002 to assist in taking care of any of these issues …. or to replace a failed alternator.