Do you have questions about the ins and outs of your BMW?

Click through these tips to learn more about proper car care.

Alternator Care

If you have ever replaced an alternator sooner than you thought was normal, you may have contributed to its demise. The most common reason for premature alternator failure is overheating. We stress the importance of adequate alternator cooling by keeping the alternator air ducting clear, but there is another way to cause an alternator overheat situation that can adversely affect water and air cooled alternators alike.

When your car doesn’t crank over and you get a “jump,” you might think, “Well, the battery will recharge while I’m driving.” You might be right, but you are also risking an expensive breakdown in the future. The alternator may even provide enough surface charge to the battery to provide enough power to start the engine the next time it is needed. However, asking the alternator to run at peak output for an extended period of time will guarantee an overheated alternator and eventual failure.

The alternator is intended to maintain the car’s electrical system, not act as a battery charger. As a final note: even when replacing the battery, make sure the new battery is fully charged so you don’t end up replacing the alternator next.

BMW Brake Hose Failure

Owners of BMW 5 series from 96’ – 03’ (E39 chassis) and 7 series from 95’ – 01 (E38 chassis) should be aware of a potentially serious brake system failure. The problem occurs when a main brake pressure hose section from the ABS/ASC/DSC hydraulic control unit ruptures and causes the brake system to lose hydraulic pressure.

Due to age and thermal exposure to engine exhaust manifold heat, this particular brake hose section slowly deteriorates, and the hose failure typically occurs during braking pressure.

At JL Motorworks, we have seen a number of these failures and can identify other potential problems during our routine maintenance program. The brake hydraulic system must be re-bled after the hoses are replaced. In addition, the cycling of the ABS hydraulic unit solenoids must be carried out. As an added level of protection, when the hoses are replaced, the JL Motorworks team will install an outer heat barrier sleeve to protect the new hoses and prevent the problem from occurring again.

Window Regulator

Your BMW’s windows seal tightly into a window channel or weather strip when closed. During the summer, if the windows are used infrequently, heat can cause the rubber weather strip/channel to stick to the glass.

A window regulator or cable and pulley system raises and lowers the window, and after months of non-use, excessive force is required to release the window glass from the weatherstrip. At the moment of initial restraint, the cable pulley/window regulator system can be damaged, leaving the window stuck.

To help avoid this problem, operate all windows on a regular basis (weekly). In addition, all window weatherstrip/channels should be lubricated as prescribed during an Inspection I/II service.

Air Conditioner Operation

When it’s hot outside, your BMW’s air conditioner works hard to keep you cool.

Unfortunately, when your AC system is overworked, it can wear out sooner than expected. These simple suggestions will help your AC system’s efficiency and longevity.

  1. Make sure the AC/heat bias regulator dial in the center dash vent is on three blue dots.
  2. The AC should be operated in recirculation mode by pushing the recirculation button (circular arrow button without the ‘A’). This will keep hot ambient air out of the cabin. If the air conditioner cools just recirculated air, the cabin will cool down faster and stay much cooler.
  3. AC programming is set at the factory to a normal setting for all North American cars. The AC can be re-programmed to accept a new setting for “hot country” that will bias the AC system sensors, mixture flaps and airflow for maximum cooling.

These steps should make your AC system more efficient and able to cycle off more frequently, increasing its lifespan and reducing repairs.

Check Engine Light

Like other components in your BMW, the engine’s performance and operations are constantly being monitored. Depending on your BMW’s year and model, the car will notify you of an engine problem via an indicator in the instrument cluster through one of the following:

  • an outline symbol of an engine

These indicators will always display when the car is first turned on to let you know it’s working. It should never be displayed when the engine is running. If it is, there is a potentially serious problem that should not be ignored even if the car still starts and runs.

Unfortunately, these indicators only come on after a problem has existed for a period of time. It’s basically a last “cry for help” from the engine management system, which can no longer substitute a value or compensate for the problem.

Diagnosing the source of the problem starts with an interrogation of the engine management system to read and interpret the stored faults.

Clogged Body Drains

If you have a 1989-1995 BMW E34 5 series and the cowling drains at the base of the windshield under the hood clog, expect soggy front footwell carpets after a hard rain. Clogged drains allow the water to wind its way through the heater box seal and into the car. If this condition goes undetected, your soggy carpets will mold and there is a good chance your air conditioning control unit and wiring will corrode and fail.

Air Flow Blockage

Clogs present a different problem on 1996-2003 BMW E39 5 series. These clogs affect air conditioning and engine cooling. These cars tend to trap road debris in the lower air conditioner condenser area.

Paper, leaves, and other road debris cause heat dissipation issues when they collect between the auxiliary fan and condenser. The clogged condenser area creates superheated air that affects radiator cooling, auxiliary fan operation, and eventually AC compressor life. Cleaning the condenser once every year or two will help alleviate these potentially expensive situations.

Get Your Car Ready For Summer

  • Switch out your BMW’s engine oil & filter as needed (you should do this around every three months).
  • Get a thorough tune-up from a professional BMW maintenance shop if necessary (check your BMW owner’s manual to see the frequency at which you should get a tune up).
  • Inspect the cooling system hoses for leaks, switch out engine coolant fluid if needed, and check drive belts for cracks or splits.
  • Have a professional test your antifreeze. This prevents your coolant from boiling in the summer.

Recommended Care for BMW Convertible Tops

The best way to care for a cloth convertible soft top is with regular care, cleaning and maintenance.

There are lots of car care products out there, but there are surprisingly few products designed specifically for cloth soft tops like a BMW’s. BMWs were born in Europe, and there is only ONE recommended product for caring for convertible tops — made by a company in the UK called Renovo. It is a safe, gentle but extremely effective line of products which are water-based and made specifically for expensive European cloth tops!

The very first rule of soft top care is to avoid all products containing silicone or chemicals of any sort, which is why Renovo is so strongly recommended.

Renovo is safe for your soft top as well as your car’s paint or clear coat, and wipes off easily if you get some on them.

To care for you beautiful convertible’s gorgeous soft top, here’s the drill:

  • Get a good scrub brush. Rub it across the back of your hand, and if it doesn’t leave a welt or scratches, it’s OK to use it on your car top.
  • Apply a good cleaner like Renovo Soft Top Canvas Cleaner. Follow the instructions and scrub thoroughly. Rinse the foam and dirt off with a hose and let dry.