The situation when something is loose inside the refrigerator compressor causes reasonable concern for the owner of the household appliance. This is usually accompanied by a characteristic metallic clang, knocking or ringing sound when the engine starts. Compressor is the heart of the cooling system, and any extraneous sounds from its body indicate serious mechanical problems. Ignoring these symptoms can lead to complete failure of the unit and spoilage of products.
In most cases, the sound of a “dangling” object inside the sealed casing indicates that one of the internal components has become detached from its fastenings or has collapsed. This could be a break in the piston rod, destruction of the suspension system of the motor itself, or critical wear of parts of the crank mechanism. Refrigerators different brands, be it Indesit, Atlant or Beko, have a similar compressor design, so the nature of the defect is often universal.
Further operation of equipment in this condition is categorically not recommended, since metal debris can jam the mechanism or damage the cylinder.
In this material we will look in detail at why knocking occurs, how to carry out initial diagnostics and whether it is worth trying to repair the unit yourself.
Compressor design and the nature of noise
To understand what exactly can be hanging out inside, you need to imagine the device hermetic compressor.
This is a steel “can”, inside which an electric motor with a piston group on springs is suspended. Such a suspension is necessary to dampen vibrations during operation.
In normal condition, the motor hangs on three springs and does not touch the walls of the casing, and all moving parts are lubricated with special oil.
If you hear something rattling inside, this means a violation of the integrity of the internal structure. Most often, the source of sound is:
- 🔨 A torn connecting rod or piston group, which begins to beat chaotically against the walls of the casing.
- 🔩 A destroyed bushing or bearing, creating a metallic ringing when the shaft rotates.
- 🔧 Broken suspension springs, which is why the motor block itself begins to beat against the inner surface of the case when starting.
⚠️ Attention: If after turning on the refrigerator you hear a loud metallic clang, and after a few seconds the thermal relay is triggered and the motor stalls, immediately disconnect the device from the network. Further attempts to start may burn the motor windings.
It is important to distinguish between the noise of the compressor and the noise of the refrigerant in the tubes.
Murbling or gurgling is a normal process of freon circulation, whereas it is metallic knock indicates a mechanical breakdown.
For accurate diagnosis, you often need to remove the back panel and listen to the operating unit, placing your hand on the body to feel the vibration.
Main reasons for the appearance of foreign objects
There are several key reasons why inside the body turns out to be an “extra” moving element.
The most common of them is broken rod (rod) connecting the piston to the connecting rod.
In this case, the piston remains in the cylinder, and the torn rod begins to dangle freely inside casing, producing a characteristic ringing sound during each startup cycle.
Another option is the destruction of the elements of the crank mechanism.
- 📉 Wear of the connecting rod bushing leads to the appearance of play, which increases over time to a knock.
- 📉 Jamming of the piston in the cylinder due to lack of oil can lead to separation of the connecting rod from the crankshaft.
- 📉 Destruction of the valve group when the valve petals come off and fall into the crankcase cavity.
⚠️ Attention: In some older models of refrigerators (for example, Soviet ZIL or early Saratov) the knocking can be caused by a torn off suction noise muffler, although this happens less often than a mechanical breakdown.
It is also worth considering the factor of the factory defects or poor-quality previous repairs.
If oil was ever added to the compressor or soldering was performed with overheating, the internal clearances could change, which led to accelerated wear.
In such cases, the part may begin to “lobble” long before the end of its service life.
Can it dangle there? frozen water?
Theoretically, if there was air and moisture in the system, an ice plug could form inside. However, ice usually blocks the capillary tube, causing a lack of cold rather than the sound of a dangling object. The sound of a “chatter” is almost always a solid metal part.
Diagnostics: how to determine the nature of the breakdown
Primary diagnostics can be carried out independently, observing electrical safety measures.
First, you need to visually inspect the compressor for external damage and check the reliability of the fastenings to the frame refrigerator.
It often happens that it is not the internal parts that have become loose, but the compressor itself on the frame shock absorbers.
For a deeper check, you will need to remove the protective casing (if any) and start the unit.
- 👂 Put your hand on the motor housing: if the vibration is transmitted to the entire body “can”, and the sound comes from the inside - the problem is internal.
- 👂 If you hear a clear knock at the moment of starting, which subsides after a couple of seconds, the shaft supports may be worn out.
- 👂 An incessant ringing indicates that the part moves freely throughout the entire volume of the crankcase.
Particular attention should be paid to the behavior of the starting relay.
If the compressor hums, but does not start, and at the same time something is clanging inside, a jam may have occurred.
At this moment the relay tries to start the motor, the shaft jerks, and a loose part hits the walls.
☑️ Primary noise diagnosis
Comparison of symptoms: table of faults
To simplify diagnosis, we suggest comparing the symptoms of various breakdowns.
This will help you understand how critical the situation is in your case and whether it requires immediate intervention.
Pay attention to the combination of sound signals and the behavior of the refrigerator compartment.
| Symptom | Probable cause | Does it work? cold? | Difficulty of repair |
|---|---|---|---|
| Metallic clanging at start | Breakage of the piston rod | No (or weak) | Replacement of the compressor |
| Constant ringing inside | Destruction of the motor mount | Yes, but with noise | Replacement of the compressor |
| Knock + vibration of the housing | Wear frame shock absorbers | Yes | Low (adjustment) |
| Buzzing and clicking of the relay | Mechanism jamming | No | Replacing the compressor |
As can be seen from the table, in most cases, when something is loose in the inside hermosealed housing, repair is impossible.
Modern compressors Danfoss, Secop or Embraco cannot be opened and restored at home.
The only correct solution is to replace the assembly.
Is it possible to repair a compressor yourself
The question of self-repair often arises due to the high cost of a new unit and work craftsmen.
Theoretically, the compressor housing can be cut, replace the broken part and weld it back.
However, in practice this requires professional equipment: a vacuum pump, a torch for brazing and a crimping machine.
⚠️ Attention: Opening the compressor breaks the tightness of the system. Without evacuation, moisture will remain in the system, which during operation will turn into an ice plug and will cause the new compressor to fail in a few months.
In addition, it is necessary to accurately select the oil and refrigerant, as well as know the valve pressing technology.
For models Atlant or Indesit It is easier and cheaper to buy a new compressor than to try to revive an old one.
Independent replacement of the compressor is possible only if you have the skills to work with copper pipes and refrigerants.
If you do not have a special tool, it is better not to risk it.
Inept actions can lead to freon leakage, which is dangerous to health, and a fire during soldering.
In most cases, calling a technician to replace the unit is the only safe solution.
Prevention and extension of service life
To avoid situations when something starts to loosen inside the compressor, it is important to follow the operating rules of the refrigerator.
The main enemy of mechanics is frequent switching on and off, as well as operation in abnormal modes.
Do not set the temperature below required and do not load hot products into the chamber.
Following simple rules will help preserve the unit:
- ❄️ Ensure good ventilation of the rear wall so that the compressor does not overheat.
- ❄️ Protect equipment from power surges with stabilizer.
- ❄️ Do not allow prolonged downtime without work, the oil may thicken or drain.
Regularly check that the refrigerator body does not vibrate against the wall or floor.
External vibration is transmitted to internal components and can accelerate fatigue failure metal.
Timely defrosting (for systems No Frost - checking drainage) also reduces the load on the motor.
Does tilt during transportation affect knocking inside?
Yes, if you transport the refrigerator lying on its side or back, oil can flow into circuit, and with a sharp jerk - tear off the suspension elements inside the compressor. Always transport equipment vertically.
Why does the compressor knock only when starting?
A knocking sound when starting is often due to the fact that oil has flowed into the lower part of the crankcase during inactivity. In the first seconds, the mechanism runs “dry” until the pump disperses the oil. If the wear is great, this sound becomes distinct. This may also indicate a weak motor suspension inside the casing.
Is it dangerous to continue using the refrigerator if something is loose?
Operation is possible only for a short time. Metal shavings from rubbing parts can enter the cooling system and clog the capillary tube or filter drier. This will lead to a much more expensive repair of the entire system, and not just replacing the motor.
How much does it cost to replace a compressor compared to buying a new refrigerator?
The cost of replacing a compressor with labor is usually 30-40% of the price of a new middle-class refrigerator. If the equipment is more than 10 years old, it is often more advisable to consider purchasing a new unit, since the resource of other components (evaporator, condenser) may also be exhausted.