How to quickly and accurately determine the condition of the engine? Check the compression in the cylinders! Is the engine running rough, you feel a loss of power, the consumption of engine oil or fuel has increased and the car has become difficult to start in cold weather? All of these problems may be caused by low compression in one or more cylinders.
To ensure that the compression test gives accurate results
Compression depends not only on the technical condition of the engine, but also on the conditions under which it is measured. Make sure that during the check:
- the compression gauge was working properly;
- the engine has been warmed up to operating temperature (up to 90 degrees);
- the throttle valve was fully open;
- spark plugs in all cylinders must be turned out;
- the starter was fully operational;
- the battery was fully charged;
- The engine air filter was clean.
How to check the level?
To find out about small or weak compression on spark plugs in the first, second or other cylinder of the engine, you must adhere to the following rules:
- the power unit must be spun up by the starter to extremely high speeds, for this it is necessary to reduce the likelihood of energy loss;
- the procedure should not be carried out on a cold engine in order to ensure maximum coupling at temperatures closest to operating temperatures;
- You must first turn off and unscrew the spark plugs from the cylinders to prevent the formation of resistance to rotation;
- you need to turn off the fuel supply so that the engine fluid is not washed off the cylinder walls;
- It is necessary to charge the battery as much as possible to effectively spin the crankshaft.
Procedure for checking compression in cylinders
- Remove the ECU fuse or wire from the ignition coil;
- Screw the compression gauge into the spark plug hole;
- The throttle valve is fully opened (press the gas pedal all the way);
- Turn on the starter for 5-10 seconds so that it turns the crankshaft;
- Check the compression gauge readings;
- Repeat steps 2-5 for other cylinders.
How to measure compression in cylinders on video:
Maintenance
According to AvtoVAZ recommendations, the 11183 engine must be serviced according to the regulations:
| Maintenance object | Time (month) or mileage (10,000 km), whichever comes first |
| Timing drive | 36/ 1 |
| Battery | 12/2 |
| Valve clearance | 24/2 |
| Crankcase ventilation | 24/2 |
| Belts that drive attachments | 24/2 |
| Fuel line and tank cap | 24/2 |
| Engine oil | 12/1 |
| Oil filter | 12/1 |
| Air filter | 12 – 24/4 |
| Fuel filter | 48/4 |
| Heating/cooling circuits | 24/4 |
| coolant | 24/4 |
| Oxygen sensor | 10 |
| Spark plug | 12 – 24/2 |
| Exhaust manifold | 12/1 |
By default, the cooling system has a volume of 7.8 liters. Red Felix Carbox 40 antifreeze is usually poured on the conveyor. Replacement is made with any coolant, taking into account the temperature range of 85 degrees. Since the internal combustion engine device is quite simple, the maintenance operation can be performed on your own.
What are the cylinder compression standards for VAZ engines?
Engine specifications must indicate “minimum cylinder compression values.” If you cannot find such data, determine the compression standards yourself using the formula:
| Compression (kgf/cm2) = compression ratio (see technical specifications of internal combustion engine) * coefficient (for VAZ min 1.2, max 1.3) |
A few examples:
- The compression ratio of modern VAZ 21126 and VAZ 21127 engines installed on Granta, Kalina and Priora is 11. We multiply the values using the formula and get the compression standards: 13,2..14,3.
- For the Vesta engine (VAZ-21129) the compression ratio is 10.45, the compression standards will be: 12,5..13,6.
- For Niva (VAZ 21213, 21314) - 11,3..12,2.
If the compression gauge values in all cylinders are within the normal range, this does not mean that everything is fine. Different compression in the cylinders is also bad. It is important that the difference between all readings is minimal. Compare the minimum and maximum compression values in the cylinders. According to technical standards, the difference should be no more than 1 kgf/cm2 or 10% .
Timing diagram Lada Granta 8 valves
- 1 - crankshaft toothed pulley
- 2 - coolant pump toothed pulley
- 3 - tension roller
- 4 - rear protective cover
- 5 - camshaft gear pulley
- 6 - timing belt
- A - boss on the rear protective cover
- B - mark on the camshaft pulley
- C - mark on the oil pump cover
- D - mark on the crankshaft pulley.
Another feature of the engine is the location of the water pump (pump), which is rotated by the same timing belt. That is, in case of coolant leaks or characteristic noise/whistle/hum in the timing drive area, checking the belt is mandatory. If the pump bearing crumbles and the belt comes off, then in addition to replacing the water pump housing and belt, you will also have to go through the cylinder head, removing bent valves from there.
AvtoVAZ uses a very reliable Gates belt as the original belt. Often the service life of the Gates belt is much higher than the service life of the pump and tension pulley of the Lada Granta 8-valve engine.
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- Lada
- Granta
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The Lada Granta was equipped with two 8-valve and two 16-valve 1.6-liter engines. Eight-valve engines with 82 and 87 hp. had an index of 11183 and 11186, respectively. Sixteen-valve power units with a capacity of 98 -106 hp. carried the index 21126 and 21127.
Reasons why there is no compression in the cylinder
Poor (small) compression in one or all cylinders indicates engine wear. There is an old and simple way to determine why compression has disappeared. You need to pour a tablespoon of engine oil into the spark plug hole and repeat the measurements:
- if the pressure has increased noticeably, it means the piston rings have poor sealing;
- if the pressure has not changed, then there may be several reasons (for example, leaking valves, broken gaskets under the cylinder head, there is a crack or burnout in the walls of the combustion chamber, in the piston bottom).
There is another, more accurate way to find out why compression has disappeared. To do this, you will need to modify the spark plug. We remove the insulator from it, and weld the valve of the car camera to the metal body. Next, set the cylinder piston to the ignition timing position, remove the radiator caps and oil filler neck, screw in the manufactured adapter and pump air into the cylinder using a pump (create pressure in it):
- if air enters the exhaust pipe, it means the exhaust valve is poorly sealed;
- If air goes into the intake manifold, there is a problem with the intake valve.
- if bubbles appear in the expansion tank, then check the cylinder head gasket;
- If there is a hissing sound in the oil filler neck, it means that the piston rings are not properly sealed.
Engine diagnostics using compression measurements in the cylinders allows you to quickly and accurately determine its condition without disassembling, and in some cases will help avoid major repairs of the power unit. Have you ever experienced a lack of pressure in the cylinders? What was the cause of the malfunction? If engine problems persist, check the fuel rail pressure.
Keywords: Lada Granta engine | Lada Kalina engine | Lada Priora engine | Lada Largus engine | 4x4 engine | Lada Vesta engine | lada xray engine | Niva engine | universal article
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It’s just the Chinese crap that’s overpricing. 16 is the wrong number
Engine compression and compression ratio. What it is?
Compression is the maximum air pressure in the combustion chamber at the end of the compression stroke. The engine compression ratio is the ratio of the total volume of the cylinder to the volume of the combustion chamber. Compression ratio. On a forced engine, depending on the final task, the compression ratio can vary significantly, reaching values of 11 - 11.5. All this is aimed at extracting maximum power from a motor of a specific size. The higher the compression ratio, the higher the power density. True, this will inevitably reduce the service life and sharply increase the risk of problems with the engine when refueling with low-quality fuel. One refueling with questionable fuel can quickly kill a “stressed” engine. So, when boosting the engine, it will not be possible to save on the quality of gasoline. Therefore, when tuning the engine, the compression ratio does not increase very significantly, usually in order to switch to a brand of gasoline that is next to the one already used in terms of octane number. In principle, indirectly, the value of the compression ratio can be judged by the brand of gasoline used - you can drive an AI-80 with a compression ratio of 9.0, and an AI-92 - up to 10.0 (provided that the gasoline meets the declared characteristics). Increasing the compression ratio - a complex process that requires precise calculations and very highly qualified mechanics. Therefore, it is highly not recommended to do this yourself. Compression. As mentioned above, compression is the pressure in the cylinder. This is why compression depends on the compression ratio (the pressure in a smaller volume will always be greater, i.e., as the compression ratio increases, the compression increases). By the amount of compression you can preliminary judge the condition of the engine. It is important to carry out the compression measurement procedure correctly. To do this, you need: the engine is warmed up, the battery is fully charged, the throttle is open, the air filter is removed, all spark plugs are unscrewed. In this mode, a fully charged battery will allow the starter to spin the engine up to 200 rpm. Compression in all cylinders should be equal. If the compression level decreases, it is necessary to find out the cause of the drop. It could be piston rings or problems in the valve mechanism, you can find out this way. 15-20 grams are injected into the problematic cylinders using a syringe. motor oil. The measurement procedure is repeated. If the pressure gauge readings have increased, the reason for the drop is in the piston rings; if they remain at the same level, it is in the valves.
Go herd the geese, you see he is silent, he has already measured the COMPRESSION, but the degree of compression is not measured, it is CALCULATED!
Measurement process step by step
There are many recommendations on how to properly check compression, and they all say that maximum pressure should be created in the cylinders. That is, the throttle valve must be opened “to the maximum”! In fact, compression is sometimes measured with the damper closed: little air enters the cylinders, and air leaks, if any, will become noticeable immediately. For example, the defect of a loose valve fit is calculated. The value obtained during measurements can be 7-9 bar - this is if the damper is completely closed. If there are 8 in one cylinder and 9 in the others, then the conclusion suggests itself.
In general, you need to count on other numbers: a new VAZ engine always produces 13 bar, and with worn rings the value drops to 11.
Repair of power unit components
As practice shows, nothing lasts forever, and neither do the components of VAZ power units. In this part of the article, we will consider the main malfunctions, as well as methods of elimination and repair.
Timing belt or how not to bend valves
Probably the most interesting question for most motorists is whether the valves on VAZ engines bend? As for the VAZ 11189 engine, we can say with confidence that the valves bend when the timing belt breaks. Of course, valves can bend for other reasons, but the most common is considered to be a broken timing belt.
Another question that car enthusiasts ask in car repair shops and on forums regarding the timing belt is how to prevent valve bending? Everything is very simple - change the timing belt and rollers according to the technical recommendations of the manufacturer. Thus, in the maintenance manuals for engine 11189, the recommended belt replacement period is 45-50 thousand kilometers.
What happens if the valve bends? Everything is very simple - after the valve mechanism is bent, such important elements as the valve guide, valve seat, and oil seals fail. Subsequently, it may happen that this problem affects the piston mechanism. In a word, if the valve bends, then you should hope for the best and expect the worst - that is, a major repair.
How to replace the timing belt and rollers:
- First, you need to remove the protective casing.
- Then, we fix the camshaft, but before that it is necessary to set the timing marks.
- Unscrew the tension roller to release the belt.
- Next, we dismantle the belt itself.
- We change the tension roller.
- Reinstall the timing belt.
The procedure for changing the timing belt, at first glance, seems to be quite simple, but not everything is so simple, and not every car enthusiast will be able to carry it out. Therefore, in order not to subsequently bend the valves, it is recommended to contact specialists at a car service center to carry out the procedure.
Water pump malfunction
The water pump circulates coolant through the engine system. This is done for cooling and to prevent the motor from burning out. The failure of such a unit means that further operation of the power unit is impossible, since overheating will occur and the first thing that will be affected is the cylinder head. To avoid this, you should regularly diagnose the part and replace it on time.
There is nothing difficult about replacing the pump. The procedure is similar to changing the timing belt. After removing the belt, unscrew the bolts securing the water pump and replace it. It should be noted that the coolant must be drained from the system and, after replacement, topped up to the required level.
Preparatory work
Before you check the compression in the cylinders of a car engine, you need to get a compression gauge. You can buy it - the price of this device (unless it is professional) is a little more than a pressure gauge - or ask your friends. This attribute must have a tip that is screwed into the candle channel, and not driven into it. The second condition for selection is the presence of a hose that connects the pressure gauge to the tip. If a rigid tube is installed instead of a flexible connector, then the configuration is unsuccessful: probably, due to the rigidity, something on the engine will interfere with the installation of the compression gauge. Finally, it is recommended to choose a device with a scale of at least 20 kg/cm2. You will also need a spark plug wrench.
The next step is to warm up the engine. This method is used most often, so we will not describe how to check the compression in a cold car. The engine must warm up to operating temperature - on average 90 degrees. And most importantly: the measurement must be carried out on a fully charged battery. Otherwise, it will crank the crankshaft weakly, and the results obtained will be unreliable.
Next, you need to carry out the following manipulations:
turn off the engine, open the hood to access the unit; open the throttle valve and lock it. Or you can do it differently: press the gas pedal all the way and hold it in that position. Compliance with this condition will allow the unit to receive the required amount of air; remove or disconnect the air filter; remove the fuel pump fuse - this is necessary in order to avoid accidental supply of fuel to the cylinders. It is difficult to figure out where the fuse is installed on your own - use the car’s operating instructions; remove the wires from the spark plugs; clean the area around the spark plugs from dirt, as there is a risk of it getting inside the engine; unscrew the spark plugs using a wrench; screw them into one of the spark plug wells compression gauge tip.
Before starting testing, excess pressure must be relieved from the compression gauge. There is a regular valve for this. Moreover, you need to use it every time before checking each of the cylinders.
