Diagnosis through camera: Engine cylinder endoscopy

Modern diagnostics internal combustion engines It's gone a long way, allowing you to look inside the unit without having to disassemble it completely. One of the most effective methods available today, both in professional services and for advanced motorists, is the use of special optical technology. Often drivers hear the phrase "look at the camera in the cylinder," which means an endoscopy procedure, which allows you to visualize the state of the walls of the cylinders, the bottom of the pistons and valves with minimal interference with the design of the engine.

This procedure is necessary when suspicious symptoms appear: a compression drop, increased oil consumption, knocking or a change in the color of the exhaust gases. Instead of removing the cylinder head, which is a time-consuming and expensive operation, mechanics use a flexible probe with a high-resolution camera. Technical inspection This way it saves a huge amount of time and money, providing an objective picture of health. piston-group.

In this article, we will discuss in detail how the procedure is performed, what equipment is required and what defects should be paid attention to first. Understanding the principles of working with the endoscope will help you to plan correctly the repair and avoid imposing unnecessary services by unscrupulous craftsmen.

Principle of operation and types of diagnostic equipment

The method is based on a videoscope or endoscope, a device consisting of a flexible or rigid probe, at the end of which is a miniature camera and a backlight source, and the image is transmitted to a monitor or smartphone, allowing the operator to study the interior in detail. combustion-boxThere are several types of devices that vary in design and purpose, and for car engines, flexible fibroscopes are most commonly used, which can bend the complex shapes of intake manifolds.

Rigid endoscopes, by contrast, provide a clearer picture without distortion, but require direct access to the subject, which is only possible with removed candles or nozzles. Modern models are equipped with rotary heads that allow you to change the angle of view by 360 degrees during the diagnosis process, this is critical for viewing hard-to-reach areas under the valves or in the area of the laboratory. piston-ring.

Image quality depends on the resolution of the matrix and the power of the LED-lighting. Weak backlight will not allow you to see microcracks, and low resolution will make it impossible to analyze the nature of wear of the walls. Professional equipment often has a function of measuring defects directly on the screen, which helps determine the need for urgent repairs.

It's important to understand that even the most expensive camera is not a substitute for the experience of the diagnostician, and the ability to correctly interpret the color gamut of nagar and the glare of oil comes only with practice. Digital processing Images can sometimes distort real colors, so rely on a combination of factors.

Preparation of the engine for visual inspection

Before you lower the camera into the cylinder of the engine, you need to conduct a number of preparatory activities, the main task is to ensure clean access of the probe inside and prevent foreign objects from entering the combustion chamber. The engine must be completely cooled to prevent burns and deformation of parts when in contact with a cold tool.

The preparation process begins with the dismantling of decorative plastic linings and access to spark plugs or fuel injectors. In gasoline engines, candles are most often twisted out, as their opening is ideal for entering standard probes. In diesel engines, the situation is more complicated: often the removal of nozzles or the use of special adapters, since the channels for incandescent candles can be too narrow or curved.

The critical step is to clean the area around the holes, and any grain of sand that falls inside the cylinder when you enter the chamber can become abrasive and cause fatal damage. honing-surfaceIt is recommended to use an industrial vacuum cleaner or compressor with a careful purge before removing the candles, and it is also worth de-energizing the ignition and power system to prevent accidental start of the starter or spark formation during the procedure.

⚠️ Warning: Never run an endoscopy on a hot engine. A sudden temperature drop can cause the camera lens to heatstroke, and the gasoline vapor in the hot cylinder can ignite from a spark of static electricity or faulty probe wiring.

Algorithm of cylinder diagnostics

The inspection procedure itself requires calmness and methodicalness, and the camera is slowly inserted into the candle well, controlling the image on the screen in real time, the first thing you need to do is look at the walls of the cylinder. The probe is carefully rotated, scanning the surface from the top dead point (BMT) to the bottom, and pay special attention to the area where the upper compression ring stops.

Then, lowering the camera down, they look at the side walls and look for signs of wear, scratches or changes in the structure of the metal. After examining the walls, the camera is brought to the bottom of the piston. Here it is important to assess the amount and nature of the deposits. If necessary, you can ask the assistant to turn the starter briefly (after turning off the ignition coils and fuel supply) to move the piston and open for inspection hidden areas.

The other step is to look at the valves, and to do that, you try to get the camera as close as possible to the edges of the cylinder, the intake valves are usually clean, but the exhaust valves often show the swelling, and if the plate of the valve has an uneven coating or visible burnout, this indicates a leakage or a problem with the nozzle. Visual control It can reveal even minor deviations from the norm.

During the inspection, it is recommended to take photos and videos of all defects found, this will help in the future to consult with other specialists or track the dynamics of engine wear in the future.

Interpretation of results: scoring, bullying and defects

The image you get requires the right decoding. The normal state for a mileage engine is that there's a thin layer of dry sofa, gray or light brown, but the black, slick coating indicates a combustible of oil or a rich mixture, and it's important to distinguish between the types of sediments, because they're different problems.

The most dangerous diagnosis that can be made with a camera is bullies. They look like deep vertical scratches on the cylinder mirror. If bullies are located at the top of the ring, and have torn edges, this often indicates the destruction of the catalyst and the ceramic dust entering the cylinders. A fine grid of scratches across the surface can be the result of overheating or oil starvation.

Type of defect	Visual signs	Probable cause	Effects of consequences
Oily scoop	Black, greasy, thick layer	Wear of oil rings, caps	Rings, ignition of kalyl
Dry charcoal	Gray or black, powdered	Poor mix, faulty nozzles.	Loss of compression, detonation
Bullies (Cratches)	Vertical furrows on the walls	Abrasive hit, overheating	The piston knock, the increase in oil consumption
Laceration of the valve	crater or hole at the valve edge	Detonation, poor mix, marriage	Power loss, three-engine loss.

Can you remove the bullies without the engine?

There are methods of decocting and using additives that can smooth out small bullies and clean the rings, but deep mechanical damage to the cylinder walls without weaving or shelling can not be repaired, the camera will show whether there is a point in chemical cleaning or the engine requires major repairs.

Particular attention should be paid to the state of holon The microrelief on the cylinder walls, which is necessary to hold the oil film, if the surface becomes mirror smooth, it indicates severe wear, and vice versa, if the chon is completely destroyed and the deep metal is visible, the engine life is exhausted.

Diagnosis of the piston group condition

The camera not only allows you to see the walls, but also assess the condition of the piston itself. There should be no melting, cracking or impact marks on the bottom of the piston. Melting the edges of the piston (often in the center) is a sure sign of detonation or potassium ignition. This is a critical situation that requires immediate intervention, because at any moment the piston can burn out.

You can also indirectly measure the mobility of piston rings through the camera, and if you see a thick layer of coking in the grooves of the piston, and the rings don't protrude from the grooves, they're buried. The rings have to protrude slightly above the surface of the piston. Sometimes you use the method of adding oil to the cylinder through a syringe, and then the compression grows and the camera shows clean grooves, the rings are the problem.

In diesel engines, you can assess the condition of the area around the piston finger through the nozzle hole, and cracks in this area ("bars") often lead to a break in the piston. Diesel fuel equipment It also affects the state of the bottom: the jet of fuel should not hit exactly one point, causing local overheating.

The color of the bottom of the piston is also considered when you look at it, and if one cylinder has a lighter piston than the other cylinder, it can indicate that you are working on a poor mixture or that you are sucking air in that cylinder, and the uniformity of wear and color of the coke across all cylinders is an important indicator of engine health.

Advantages of the method and frequent errors in the examination

There are some advantages of using a camera in an engine cylinder, which is, first of all, keeping the engine tight because it doesn't break the integrity of the gaskets. And you get documented proof of the condition of the engine, which is useful when you buy a car or evaluate the quality of the repairs that you've done, and the cost of this diagnostic is not comparable to the cost of disassembling the engine.

But there are some common mistakes, and the main one is the misinterpretation of glare, and the metal surface of the cylinder reflects the light of the endoscope lamp, and the inexperienced user may mistake the glare for a crack or scratch, and you need to change the angle of the camera and the focal length to make sure there's a defect.

⚠️ Attention: Don't force the camera if it's stuck. The flexible probe can be folded by a loop inside the cylinder, and it can't be removed without removing the head of the block.

Another mistake is ignoring the purity of the tool, a dirty camera lens will give a blurry image that cannot be analyzed, wipe the lens with a special wipe before each new cylinder, and don't rely on one diagnostic method: endoscopy data should always be compared with compression measurements and engine idling analysis.

In conclusion, regular prophylactic endoscopy (e.g., every 50,000-70,000 km) can detect problems early, and timely decoking or replacement of the catalyst detected by the camera can extend the life of the engine by hundreds of thousands of kilometers.

Can I use a conventional boroscope with AliExpress for diagnosis?

Yes, but with reservations: Cheap models often have low resolution and low lighting, which will not allow you to see microcracks, and their probes can be less heat resistant. They are suitable for amateur inspection of the loot, but for professional diagnosis of bullies, it is better to use specialized equipment.

Do I need to remove the intake manifold for endoscopy?

In most modern cars, access through candle wells allows you to view up to 80-90% of the surface of the cylinder without removing the manifold. Removing the manifold is required only in specific cases when the engine design does not allow you to enter the probe at the desired angle, or to inspect the intake valves from the manifold side.

Will the camera show the wear of the rod liners?

No, you can't see the rods directly through the candle hole, but the indirect sign of wear (knocking) is that there's a metal shaving on the drain plug magnet or on the bottom of the piston that you can see with the camera.