In this article, we will try to discuss about the signs of malfunction of the key components of any car. So that the car owner could independently, by the most subtle signs, understand that his car needs urgent repair, without bringing the situation to the extreme. 

Today we will tell you about the signs of malfunction of perhaps the most important component of the car – the engine.

Main Signs Of Engine Failure

In order for engine repairs not to cost you a pretty penny, you need to pay attention to the first signs of engine malfunction and (or) its natural wear and tear in a timely manner. Only timely detection of engine malfunction and major engine repairs will not only save money on paying for engine repairs, but also save money on its spare parts, the cost of which often exceeds the cost of engine repairs.

1. High Oil Consumption

Increased oil consumption means topping up oil for 10 thousand km of mileage more than one liter-one, and this is a sign of wear of oil scraper rings and (or) oil scraper caps (valve seals). The maximum oil consumption is considered to be from the mark “max” to the mark “min” on the dipstick for 1000 km of mileage for gasoline engines. 

For diesel engines and for turbocharged engines, the norm for oil consumption is higher, but should not exceed the norm set by the manufacturer, which is indicated in the vehicle operating instructions or in the engine repair specifications.

Important advice: buy and use good quality oil. Before starting any repairs, try using motor oil of this particular manufacturer. Many car owners who had “oil consumption” noted its reduction.

You can also avoid costly repairs by replacing seals, valve guides, and engine rings in a timely manner.

2. Smoky Exhaust

Smoke from the exhaust pipe can be white, black, or other shades (depending on the additives in the fuel and the type of fuel itself). The color serves as an important diagnostic sign and directly indicates the malfunctions that have occurred in the engine. 

White smoke on a warm engine is 100% wear of the oil scraper caps and (or) valve guides, and it is also a sign of wear of the oil scraper rings of the engine piston group. You can avoid costly repairs by replacing seals, valve guides, and engine rings in a timely manner.

3. Wear Of The Oil Scraper Rings

A rich mixture is “treated” by checking and/or adjusting the fuel supply system: carburetor or ESU (throttle position sensor, MAP, other sensors). You can avoid costly repairs by timely replacement of engine rings, or by checking and adjusting the fuel supply system.

4. Gases From The Ventilation System

Gas and vapors come out of the crankcase ventilation hose in time with the working strokes in the cylinders (on a serviceable engine, gases and vapors come out without a clear pulsation of the flow.) wear and sticking of rings. Replacing the rings, decoking will help.

5. High Fuel Consumption

With an urban driving cycle with frequent stops, gasoline consumption can increase by 2 times and amount to about 15 liters per 100 km.
Possible malfunction of the fuel system and engine ECU. You can treat this by cleaning the injector or determining the ECU malfunction. Unless it is a fuel leak (urgently check the fuel lines, especially after replacing the fuel filter, cleaning the injector, driving off-road).

Otherwise, you have to replace the rings, repair the cylinder head (adjustment, replace the valves, seats, and reboring the engine is possible).

6. Loss Of Engine Power

The power loss is considered significant if the acceleration time of the car from zero to 100 km/h with gear shifting increases by more than 25%, and the maximum speed decreases by more than 15%. 

You can not neglect the maximum speed tests, so as not to frighten others and yourself, but measure the maximum speed in first, second or third gear (in 1st gear – up to a speed of 37-38 km/h, in 2nd – up to 51-52 km/h). An experienced driver will determine the loss of engine power of his four-wheeled favorite without any chronometer.

The main reason for the decrease in power of an old engine is due to deterioration in compression.

7. Mechanical Wear Of The Cylinder, Rings And Piston Leads To A Decrease In Compression

The engine power can be assessed by compression as follows: 12 kgf/cm2 – excellent, 10 – mediocre, 9 kgf/cm2 – bad.

If the compression is low, (this is especially evident during cold starts in winter – the mixture needs to be warmed up during compression, so it ignites worse. In severe frost, an old and worn-out engine may not give a single spark. The reason for the decrease in engine compression can be determined using an old but proven method. 

It is necessary to pour several cubes of oil into the spark plug hole in the cylinder (5 is enough) and recheck the compression. If it increases, then it is the rings. Otherwise, it is the valves, since oil injection for valves does not matter at all.

This malfunction is “treated” by replacing the rings, repairing the cylinder head (adjustment, replacement of valves, seats, valve guides, engine boring is not excluded).
In engines with ECU, a drop in power can also be caused by incorrect operation of one of the oxygen sensors and (or) other ECU sensors of the engine. In this case, your vehicle needs computer diagnosis, especially if the “CHECK” light is on.

8. Engine misfires – engine runs rough

The main and most common reason is dirty injectors, problems with the ignition system, engine ECU. You can repair this by flushing the injector, determining the fault in the ignition system and ESU.

Otherwise – major engine repair with all the ensuing consequences: boring or liner, grinding of the crankshaft, replacement of rings, possibly liners. The reason is very low compression with a difference in cylinders of up to 3 atmospheres.

If you have detected a knock or an extraneous uncharacteristic noise, knock, grinding, engine – urgently take all measures to turn off the engine! Contact a specialist from an auto repair shop! Perhaps this will help you save a decent amount of money on engine repairs.

9. Oil Pressure Too Low

Too low oil pressure is one of the main signs of major engine repair. The following faults are possible:

• The oil intake in the engine crankcase is clogged
• Oil pump drive failure
• Oil is too dirty
• Oil viscosity does not match the season, old, or not for the engine at all
• Oil filter is clogged
• Oil pressure sensor failure
• Crankshaft liners are worn.

The latter entails mandatory replacement of liners, and often grinding of the crankshaft, as a consequence – major engine repair.

Rough engine operation – detonation, premature ignition, individual flashes in the cylinders after the ignition is turned off. As a rule, a malfunction of the ignition system (incorrect adjustment mainly in cars with a throttle valve) or low-quality fuel. If the car is equipped with an ECU and the check is on, you need computer diagnosis – a malfunction of the engine ECU sensor.

10. Engine Ring Sticking

The reason for sticking is natural wear of oil scraper rings, poor quality fuel and oil, especially irregular replacement. Also, the reason for sticking of rings can be a long pause in engine operation, engine overheating, low oil pressure.

Ring sticking can be “treated” by decoking. It helps in cases where sticking has not resulted in serious consequences associated with ring breakage and destruction of the piston and (or) cylinder surface. 

11. Engine Overheating

The consequences of engine overheating are unpredictable and often appear not immediately but after several thousand kilometers. Here you can get off with a slight fright, or you can “get” a full overhaul – as luck would have it – after all, engine overheating is a lottery.

Engine overheating can cause all of the above malfunctions. Do not allow the engine to overheat! Especially for a long time! If the engine overheats anyway, do not delay and contact a specialist for automotive service, it will not make things worse.