General information about the setup (BMW 5 Series E28)

The term "setup" is used in this manual to refer to a set of procedures rather than to a single procedure.

If the routine maintenance schedule is strictly followed from the date of purchase, with frequent checks of fluid levels and condition of high wear components as suggested in this manual, the engine will remain in good working order for a long time and the need for any additional work will be kept to a minimum.

More often, however, the engine is not running efficiently due to neglect of regular maintenance. This happens even more often when buying a used car, the owners of which did not bother with frequent and regular checks and maintenance. In this case, in addition to the usual routine maintenance procedures, it will be necessary to tune the engine.

The first step in any tuning or diagnostic procedure to improve engine performance is to check the compression ratio in the cylinders. Checking the compression ratio (see section Engine Component Overhaul Procedures) will help determine the condition of the internal engine components and should serve as a guide when performing tune-ups and repairs. If, for example, a compression ratio check indicates severe internal engine wear, a simple tune-up will not improve its performance and will be a waste of time and money. Since the compression ratio check procedure is so important, it should be performed by a specialist who has the equipment specifically designed for this purpose.

To get the engine into good working order, the following procedures are most often required.

Minimal setup

• Checking all fluids related to engine operation (Section Checking fluid levels)
• Checking the condition of all engine compartment hoses (Section Checking the condition and replacing the engine compartment hoses)
• Checking and adjusting the tension of drive belts (Section Checking the condition, adjusting the tension and replacing the drive belts)
• Cleaning, inspecting and checking the battery charge (Section Checking battery condition, care and charging)
• Replacing spark plugs (Section Checking and replacing spark plugs)
• Inspection of spark plug wires, distributor cap and rotor (Section Checking and replacing spark plug wires, cover and distributor rotor)
• Checking the Air Filter (Section Replacing the air filter)
• Checking the cooling system (Section Checking the functioning of the cooling system)

General settings

All the above minimum setup points, plus...

• Checking the ignition system (see chapter Ignition system)
• Checking the charging system (see chapter On-board electrical equipment system)
• Checking the fuel system (see chapter Power supply system)
• Replacing the spark plug wires, distributor cap and rotor (Section Checking and replacing spark plug wires, cover and distributor rotor)

Weekly checks

Identifying the causes of leaks

The appearance of puddles on the garage floor or driveway, obvious traces of moisture under the hood or under the car require an investigation into the causes of possible fluid leaks. Sometimes it is difficult to determine the source of the leak, especially if the engine compartment is significantly contaminated. In addition, the leaking oil or fluid may be carried back by the oncoming air flow away from the source of the leak, creating a false impression of its location.

Most oils and fluids used in cars are poisonous. Wash them off immediately if they come into contact with your skin and change contaminated clothing without delay.

The smell of the leaking fluid may be a clue to what is leaking. Some fluids have a characteristic color. Another way to find the leak is to thoroughly clean the car and park it overnight on a clean sheet of paper. Remember that some leaks only occur when the engine is running.

Oil from the oil pan

Engine oil may leak through the oil pan drain plug...

Oil from the oil filter

...or from under the base of the oil filter.

Gearbox oil

Transmission oil may leak through the seals on the inner ends of the drive shafts

Antifreeze

Leaking antifreeze often leaves behind crystal-like deposits.

Brake fluid

Leaks around the wheels almost certainly mean a brake fluid leak.

Power steering fluid

Hydraulic fluid may leak through the nipple connections on the steering gear housing.