BMW 3 Series E30

since 1983-1994 release

Repair and operation of the car

Whether all as it should be with the car engine? Can it is time save money for performing computer diagnostics, and even for repair? To answer these questions to you will help several advice of the autoengineer, it is a lot of years engaged in repair of import cars.

Before seeing a doctor, each of us is engaged in self-diagnostics. At the same time we do not do ourselves roentgenoscopy, we do not use the electrocardiograph and other sophisticated devices. Simply we feel a forehead, we examine a throat, we listen whether sizzles in a breast, whether swells out a stomach, whether mangles a waist. From devices traditionally we use thermometers and, maybe, the watch at measurement of pulse.

Here so, simply, we define whether the organism normally functions. And it turns out!

The car engine – the same organism. For its exact diagnosing and treatment there are many cunning devices, devices and tools. Various exact techniques and receptions demanding thin knowledge of the internal device are used. We plan to tell about them in detail in the near future.

For a start we suggest to master things, simpler for understanding.

Let's try to understand what it is necessary to pay attention to, operating the car: what needs to be felt, where to look, where to listen and, maybe, even to smell to understand how the engine feels. You do not want to study together with us – get one hundred dollars from a purse and go to computer diagnostics. Automobile "medical care" paid!

Primary survey

Present that you the kind doctor. Having entered into chamber (garage), approach the patient (car), surely greet, tell it several tender, calming words and suggest to undress to a belt (open a cowl).

Begin with external survey of the engine. Remember that nothing reflects internal wellbeing as the pleasant, well-groomed, radiating with health appearance.

Strong general impurity of the engine, as well as existence of intensive local leaks, on the contrary, testifies about reeled health. If in the evening, leaving the car, you providently enclosed the blank sheet of the newspaper under the engine, take out it and examine. Leakages of oil and other operational liquids in a night will leave marks on which you will be able to establish sources of leaks on the newspaper and to define their intensity. Than it is higher, those need rather to take measures for elimination of malfunctions.

The following step – check and bringing to norm of level of all operational liquids. First of all we are interested in engine oil and cooling liquid (antifreeze) as their shortcoming most strongly is reflected in technical characteristics of the engine.

There is a wish to remind and about they are believe, I do not joke – that it is necessary to be convinced available fuels of a tank. Practice shows that some inattentive drivers nearly to death torture a starter and the rechargeable battery, having forgotten that before the good fellow should be fed and given to drink, and then – on a shovel and in the furnace.

At the same time check a tension of driving belts of hinged units of the engine (the pump of the cooling system, the generator, the pump of the power steering, the conditioner). Make sure that belts do not sag and are not torn off. If everything is all right, shake off trousers and – for a wheel.

Before start of the engine

You do not hurry to start the engine at once. Haste here to anything! In the beginning turn a key in situation "ignition"... As a rule, at the same time on the dashboard of all modern cars a number of bulbs lights up. At this stage we especially are interested in two.

The first – a bulb of emergency pressure of oil, the second – a control lamp of a subcharge of the accumulator which indicates readiness of the generator to get into gear after start of the engine. Both at the included ignition even before start of the engine have to burn with bright red light. And if one of them does not burn? If the subcharge bulb was not lit, it is half the problem if the bulb of emergency pressure of oil does not light up - it is disturbing "call". Be attentive, you lost control over the lubrication system! Oil pressure in the engine – the main indicator of serviceability of the unit. Without controlling oil pressure, you risk "to have" capital repairs of the engine with all that it implies.

The cause of defect consists or in bad contact the plug sensor, or in the sensor. It is necessary to look for the sensor, as a rule, around an oil filter. Malfunction needs to be eliminated. Only after you were convinced that everything is all right, start the engine.

"Cold" start-up

The serviceable engine with well adjusted fuel supply systems and ignitions and the serviceable rechargeable battery is started from one attempt within 3–5 seconds. Steadily arising problems with "cold" start-up testify to malfunctions. Let's assume, we avoided it, and the engine was started...

We look at the dashboard. Two bulbs concerned above are obliged to go out.

If during 5 sec. the bulb of pressure of oil continues to burn, stop the engine!

Possible reasons: low level of oil, is faulty the oil pressure sensor; the grid of an oil receiver of the oil pump is hammered; the oil pump is faulty; big wear of radical and conrod bearings of a bent shaft.

If oil pressure as it should be, we start inspection of the engine in the warming up mode.

Warming up of the engine

Frequency of turns of not heated-up engine approximately by 1,5 times exceeds the passport frequency of idling, a component usually of 700-900 rpm, and has to decrease smoothly in process of growth of temperature of the engine.

After 7–10 minutes from the moment of start-up temperature of the engine has to reach level about 80 °C and be stabilized (as well as single turns).

If your car is equipped with the tachometer and the arrow device showing temperature of cooling liquid, it is easy to check this process.

When warming up proceeds according to the above described scenario, the system of idling and the cooling system of the engine work normally.

If temperature of the engine does not reach the necessary level, most likely, the valve thermostat is guilty. It is much more reasons of an overheat of the engine and they are reflected in the technical reference.

After the engine enough gets warm, and turns of idling are stabilized (you learn about it from indications of control devices), time to listen as the motor sings will come.

Beautiful, sonorous voice – a healthy organism

Doctors assure that in relation to the person this statement is completely fair. The same can be told also about the engine.

The serviceable engine publishes a uniform rumble and "ticks" as hours. Some masters say that he "whispers". Despite figurativeness of expressions, you for certain understood what they mean.

If the engine works unevenly, with failures, periodically vibrates, know: it testifies to its malfunction. Sometimes malfunctions – a consequence of wear of details of the engine and falling of a compression in cylinders, but most often are the reasons leakage of an inlet path, the littered air filter, failures in work of system of ignition and fuel system. There is a wish to stop on those cases when the engine as speak, "troit", that is one of cylinders does not work.

Using method of a serial detachment of high-voltage wires from spark plugs, it is simple to find "saboteur". As soon as you get on the faulty cylinder, kind of work of the engine will not change.

Often the cause of defect can be defined having examined a spark plug. It allows to learn a lot of the engine, interesting about a state.

It is necessary to mention extraneous noises and knocks. At once we will make a reservation that the similar method of diagnostics is "aerobatics" and on forces to not all professionals.

Motorists should mean that any sharp metal sounds testify to a neipravnost. If they are "published" by hinged units (the generator, a pomp, the hydraulic booster) is half the problem. It is possible to define "responsible" for noise, consistently taking off driving belts of these units. If after removal of the next belt the foreign sound disappeared, shake the corresponding pulley for definition of a radial and axial side play of bearings. Most often they are troublemakers.

The knocks proceeding from a belly of the motor threaten with much bigger troubles. Listen to them on various power setting by means of an automobile stethoscope or if it is absent, a dry stick with a diameter about 10 mm from solid wood (it is pressed to a cheekbone below an ear lobe). In such way it is possible to reveal defects of the gas-distributing mechanism, tsilindro-piston group, the krivoshipno-conrod mechanism.

Once again we will emphasize that to make the diagnosis, the ear for music is not enough, it is necessary to have professional experience and excellent knowledge of "materiel".

A sound mind in a sound body

Diagnostic inspection would be incomplete without analysis of smoke of an exhaust of the car. It is already rather heated-up so it is a high time to approach its "loin" and to glance to a horse "under a tail".

The exhaust of the serviceable engine is almost colourless. The exhaust pipe leaves hardly distinguishable easy smoke of white color which intensity amplifies by sharp pressing the accelerator pedal.

In frosty weather the serviceable car reserves quite dense clouds of white steam (not to confuse to smoke!), the fuels demonstrating full combustion.

To long inhale exhaust gases – is more expensive to itself. We suppress the engine. But it is not the final yet. It is worth surveying an internal surface of a stopper of a maslozalivny mouth. Existence of traces on it the made foam emulsion of lurid color – very disturbing symptom speaking about infiltration in antifreeze oil. Having uncovered a broad tank or a radiator, survey antifreeze. Attention: to avoid a trauma, it is necessary to do it on the cooled-down engine! An oil film on the surfaces of antifreeze, the same as the made foam engine oil – harbingers of urgent repair of the engine.

Here, perhaps, and all. We completely examined "patient", having passed literally from a nose tip to a tail. Also used at survey the equipment not expensive, inaccessible to most of motorists, and what is given us by nature: sight, hearing, sense of smell and, of course, mysterious "gray substance".

Analysis of smoke of an exhaust

Oily ring corbel 6-8 mm wide on an external surface of an exhaust pipe of the car ("a mourning rim") – the investigation of the raised oil consumption. Capital repairs of the engine are inevitable.

Smoke of black color

Sign of incomplete combustion of fuel. The power supply system prepares very rich mix and needs adjustment.

Smoke of a gray (violet) shade

Sign of the raised oil consumption. The engine demands replacement of oil scraper caps or repair of tsilindro-piston group.

Dense white smoke

Sign of a burn-out of laying of a head of the block of cylinders of the engine. Cooling liquid gets to the combustion chamber.

Smoke with a smell of exhaust gases from the removed branch pipe of system of ventilation of a case (sapun) of the engine

Sign of break of the fulfilled gases in an oil case because of the increased gaps in tsilindro-piston group.