Mitsubishi Lancer 9. Screeching, knocking or whistling during engine start
The appearance of extraneous sounds in the engine compartment during or immediately after starting the engine is a reason for diagnosing and checking the internal combustion engine. Various deviations from the norm may occur as a result of wear of individual elements of attachments, drives, bearings, pulleys or belts. Also, one should not exclude the possibility of a breakdown of the power unit itself and its components. Drivers often notice that when starting the engine on a cold, a rattle is heard, something creaks in the engine, a whistle appears, etc.
It should be noted that usually many sounds are heard better at the moment of a cold start, although in some cases the noise does not go away even after the power unit has warmed up. It should also be added that in some cases the problem is noticeably progressing, that is, the sound increases each time or gradually. In other situations, extraneous noise may not change its tone and intensity for hundreds or even thousands of kilometers.
In this article, we will talk about what breakdowns can lead to the fact that noise is heard during a cold start of the engine, as well as how and by what additional signs you can determine the malfunction yourself.
A rattle is heard when starting the engine
If the driver turns the ignition key to the "start" position and at that moment a rattle is heard, while the noise disappears after the engine "grabs" and starts to work on its own, then the most common cause is considered to be a starter malfunction.
If, when starting the engine, a starter rattle is heard on a cold or hot, then there may be several reasons for such a malfunction.
As a rule, it is necessary to check the solenoid relay, starter bendix and flywheel. The fact is that the bendix may not engage with the flywheel properly, as a result of which a crack is heard when the engine is started or a characteristic rattle of the starter appears.
Whistle is heard when starting the engine
The whistling sound at the time of starting is usually made by the alternator belt or the water pump of the cooling system (pump). The malfunction manifests itself in the form of a high-frequency squeak or squeal after starting the internal combustion engine, and can also make itself felt already on a warm engine when you sharply press the gas pedal and increase the crankshaft speed.
In case of a problem with the belt, it is necessary to check its condition and tension. Sometimes it helps temporarily to apply special rubber care compounds that allow the surface of the belt to remain soft and supple, protect against cracking, etc. With a clear weakening of the tension, the alternator belt must be tightened, while checking the condition of the pulleys and tensioner in parallel. We add that it is not recommended to tighten a strongly stretched belt, since the whistle will appear again after a short period of time. In this case, and also when it is not possible to further tighten the alternator belt, only replacement is shown. If the belt is normally tensioned, does not slip on the pulleys, but still whistles, then it may be of poor quality and needs to be replaced.
We also add that the cause of the whistle can be not only the belt, but also the generator itself. More precisely, problems may arise with the bearings of its drive. This is indicated by the characteristic rustling, whistling, slight crackling while the engine is running at idle.
The pump also emits a thin whistle at idle, the problem may be accompanied by a rumble or crackle. This feature is the reason for the mandatory check and replacement of this element.
To check the generator and / or pump, you can take a block of wood, you can also attach a tin can, etc. to the end of a wooden stick. Then one end of the bar or stick is applied to the drive area of the generator or pump with the engine running, and the other end of the bar or a tin fixed to the stick is brought to the ear. This solution allows you to more accurately determine the source of noise and localize the fault. By the way, if possible, instead of a home-made device for listening to noise, you can use the so-called car stethoscope (sometimes they use a medical one).
If the noise source is not fully installed, then it is necessary to remove the alternator belt, after which the pump or alternator pulley is turned sharply by hand. The appearance of noise, difficulty during rotation, beating, play and other abnormalities will indicate a problem. In the case of a generator, the device can be repaired by replacing the bearings. It is recommended to change the pump immediately, since on many cars the jamming of the water pump leads to a broken timing belt.
We also recommend reading an article on how to check the pump on a car without removing it. In this article, you will learn about ways to check the performance of a water pump, as well as methods for self-diagnosing malfunctions of this element of the engine cooling system.
An additional reason for replacing the pump is considered to be the appearance of streaks of antifreeze or antifreeze at the place of its installation. Coolant leaks pose a danger in the form of overheating of the internal combustion engine, a broken timing belt means that the piston hits the valves, causing the valve to bend. Ultimately, if these problems are ignored, the motor may need an expensive or even major repair.
Knocking sound when starting the engine
The appearance of a knock in the engine should be divided into problems with the gas distribution mechanism and the elements of the internal combustion engine itself (KShM and CPG, pistons, connecting rods, crankshaft, etc.) Extraneous sounds in the timing area may indicate significant wear of the rollers, belt or timing chain defects.
The rollers may whistle, howl, crunch, or rattle. In some cases, the timing belt rubs over the protective cover. We also note that on motors with a chain, when the chain itself is stretched or the tension is insufficient, the sound resembles a rustling chirp, and pops can also be heard. If you increase the speed, such sounds disappear and appear again after releasing the gas. In this situation, the timing chain needs to be tightened or changed.
A characteristic knock of the gas distribution mechanism is the knock of intake and / or exhaust valves. Such a knock differs in frequency from other knocks, has uniform intervals. The fact is that the camshaft rotates twice as slowly as the crankshaft. Knocking can be caused by incorrect adjustment of the thermal clearance of the valves.
On motors with hydraulic compensators, a common cause is the failure of the latter or clogging of the oil supply channel in the main valve. In this case, the sound is sonorous, clear, well audible in the valve cover area. Note that on many cars, after a cold start, the hydraulic lifters knock for several seconds until engine oil reaches them. This is considered the norm. If the knock does not go away after the internal combustion engine warms up, then you need to contact the service or solve the problem yourself.
Now about the knocks in the engine itself. After starting a cold unit, you can hear the pistons knocking in the cylinders. The thud is dull, similar to hitting pottery. The piston knock is most pronounced at idle, as well as at low revs under load.
Also, a knock on the main or connecting rod bearings of the crankshaft (crankshaft plain bearings) may appear in the engine. Such a knock has a metallic tint and is slightly muffled. As a rule, at the initial stage, a malfunction manifests itself after starting the engine in the event that you sharply press the gas in idle mode.
The knock increases in frequency as the RPMs increase. The axial play of the crankshaft also leads to the appearance of knocks, while the sound is sharper, it differs in that the intervals between blows are uneven. It is most clearly audible when the crankshaft speed changes smoothly.
As for connecting rod knocking, a common cause is a problem in the connecting rod bearings. Such a knock is sharp, it is clearly audible when you sharply press the gas pedal. During diagnostics, a knocking piston or connecting rod can be determined by turning off the spark plug on each cylinder in turn.
What else can knock, make noise or whistle in the engine after starting
As you can see, there are a lot of reasons for the appearance of knocks and noises. At the same time, it should be added that during the start of a cold engine, especially in winter, increased noise and chirping can be emitted by the injector nozzles themselves on units with a pressurized fuel injection system.
In some cases, this does not indicate any malfunction, since after a slight warm-up, the noise intensity decreases or the extraneous sound disappears completely. Knocking can also occur at the time of starting in the cold due to heavily hardened ICE cushions (the engine is conditionally fed at the moment the starter rotates slightly forward, after starting it “bounces” back).
Another cause of whistling or rustling may be the power steering pump. At the time of launch, a squeal, squeak, howl or whistle can be emitted by both the pump itself and its drive, as well as the steering rack, in which the power steering fluid begins to move.
Also, one should not forget about the air conditioner compressor, especially if the engine is started in parallel with the air conditioner turned on or the climate is activated immediately after starting. The compressor drive or the compressor itself is often the cause of extraneous noise.33 ..
Many faults in a car can be identified by sound. When some third-party noises appear in the form of a rattle, howl or whistle, this may signal a breakdown of one of the auto components. Some malfunctions are quite easily eliminated along with the accompanying symptoms in the form of annoying and nasty sounds. But there are certain signs of breakdowns that appear most often. Most often, when starting the engine, a whistle is heard, the cause of which can be a number of factors. At the same time, such unpleasant sounds can also be with the engine already running. Next, we will talk about the causes of such phenomena and how to eliminate them.
Engine whistle when starting and running
It is always nice to realize that your car is fully functional and will not cause inconvenience at the most inopportune moment. However, this is not always the case, and many car owners are faced with a number of manifestations of the failure of some parts of the car. This makes people doubt their "iron horse", and such a car obviously will not add positive emotions. The most common signal of a breakdown is a whistle when starting the engine. Moreover, not only owners of old cars face it, but also practically new ones that have recently left.
The reason that a whistle is heard when the engine is running can be a number of different malfunctions in the car engine. Usually this is not so dangerous a sign as annoying. Although if the motor began to make such extraneous sounds and the engine whistles more and more, then it is obviously impossible to delay the elimination of this problem. Some ignored faults can lead to costly repairs and a host of problems.
Belts
One of the main causes of whistling when starting the engine is the belts of various drives in the engine compartment of the car. Poor tension and their wear entails the appearance of that very annoying whistle, which can increase along with an increase in engine speed. Or maybe, on the contrary, disappear when you press the gas pedal. In any case, the sound made by the belts is very well audible and impossible not to notice.
When a whistle appears, the first thing to do is check the tension of the drive belts. The first step is to check the tension of all drive belts. If any of them is weakened, then slippage is possible, which leads to a whistle when the engine is running. In this case, you need to tighten the belt to acceptable limits in order to leave it with a normal free play. Another reason for slipping belts can be dirt and oil that have fallen on them. In this case, it must be thoroughly cleaned, and it is best to replace it with a new one.
Most often, the alternator belt delivers trouble in terms of noise. A whistle appears when the engine is started and disappears when the engine speed increases, since the belt enters the same amplitude with the rollers and pulleys. This can threaten with an insufficient battery charge and all the problems that follow from this. It also happens that the engine whistles, and then suddenly stops making this sound. At the same time, no changes are immediately observed. And the reason for this may be a broken alternator belt. After it breaks, charging the battery with the engine running stops. This is usually signaled by a special light on the instrument panel, but not all drivers notice it and attach some importance to it. Such inattentive car owners run the risk of being left somewhere in a deserted place with a dead battery.
Another most common cause of whistling from the engine compartment of a car is. Here the consequences of ignoring the problem can be much more serious than in the previous case. The problem here is not so much in the belt as in the bearing, but you should definitely pay attention to this. A broken timing belt can be followed by a major overhaul of the engine due to bent valves, which costs a lot of money. Therefore, it is necessary to react in a timely manner to all kinds of whistles during engine operation and not to bring the situation to extremes. This does not apply to all types of motors, but the real problem is widespread.
In most cases, the whistle in the engine when cold is caused by the same belts. If it disappears when the engine warms up, then the reason is definitely in them. During the cold season, there is a chance that the grease in the alternator belt bearing can become very thick and the belt will not be able to rotate the alternator pulley, simply slipping. The solution to this problem can be the replacement of this lubricant and the tension of the alternator belt. But before that, you need to make sure that the alternator pulley generally spins on its own and is not jammed. Therefore, as you can see, the whistle on a cold engine is eliminated quite easily.
If you hear some kind of whistle when starting the engine and subsequently during its operation, then first of all pay attention to the tension of all belts in the car engine and check their condition. It is possible that some of them need to be tensioned or replaced.
Rollers and bearings
Other elements of an automobile engine that can make unpleasant noises are all kinds of bearings and rollers that are present in many motor components. Often, in the event of a malfunction, they make sounds slightly different from the usual whistle - a low pitched whistle. This sound appears when the engine is still running at idle, but increases with increasing speed and immediately disappears or becomes much quieter. If you have determined that the engine is whistling precisely because of these elements, then this can be “cured” by replacing the failed parts.
Intake system malfunctions
If a whistle is heard during engine operation, and you have already made sure that the reason does not lie in something else, then most likely some kind of malfunction has appeared in the engine intake system. This can be either a throttle valve, which periodically jams and creates specific air turbulences, or a PCV intake valve, which is responsible for the recirculation of crankcase gases.
In the first case, the whistle during engine operation is eliminated by thorough flushing. But in order to clean it well of dirt, it is necessary to completely remove this assembly, which should not be forgotten.
In the second case, the problem is a clogged intake PCV valve. Hot air from the crankcase cannot circulate normally because of this, which leads to oil being squeezed out through the seals due to excessively high pressure and the appearance of that very whistle when the engine is running. The real problem is “cured” by ordinary cleaning of this valve. To do this, you need to dismantle the valve, which is located either on the valve cover or next to the air filter on the crankcase vent tube. If the valve is metal, then all cleaning products that will not scratch the surface are fine. In the event that it is plastic, then too aggressive aerosols and liquids should be avoided. After that, just put the valve back in place and the whistle will stop.
Turbine malfunctions
Many modern cars are equipped with turbochargers, which significantly increase their power and driving performance. But this is another node in the engine that can signal its malfunction with a characteristic and loud whistle. The reason for this may be an air leak at the junction of the engine and turbocharger. Usually such sounds speak of the imminent "death" of this important detail. Most often this malfunction occurs on machines that consume diesel fuel. Therefore, the owners of such cars know that the whistle of a diesel engine turbine does not lead to anything good.
What to do when a whistle appears from under the hood?
We have listed all the possible malfunctions in which the motor and its components can make a whistle when the engine is started or during its operation. To eliminate most of them, the car owner does not need to have any special professional skills. With the replacement of many belts and rollers, with their tension, as well as with the cleaning of the elements of the intake system, you can handle it yourself. But if you are not sure that you can cope with such problems, then it’s better not to delay them, but contact the car service to the masters of their craft and then you can avoid much more expensive repairs and a lot of unnecessary troubles that can overtake you by surprise.
Surely every driver noticed the appearance of a characteristic whistle in the engine compartment. Indeed, this is an unpleasant moment, both for the driver himself and for the people around him. The most important thing is to understand that the whistle, depending on the places of its manifestation, will differ significantly and, accordingly, by the nature of the whistle, an experienced driver or a service station master can immediately determine the node from which unpleasant sounds occur.
What can whistle under the hood
As described above, whistling can come from different mechanisms due to some reason. And it is important to remember that when a whistle appears, this does not always mean some kind of serious malfunction. So what can serve as a source of whistles of a different nature?
- Generator belt;
- Generator belt tensioner roller;
- Power steering pump bearing;
- Timing belt tensioner;
- Air conditioning compressor bearing;
- Water pump drive (pump);
- Membrane pressure regulator valves.
The above are the main elements of the engine compartment of the car from where the whistle can be. But again, it is important to understand and distinguish the type of whistle. If the cause is a weakened alternator belt, then you need to know how the whistle manifests itself when rubber rubs against metal. If the whistle is similar to the sound of metal rubbing against metal, then these are bearings and rollers.
Causes of a whistle under the hood
Increased humidity. This is the main reason for the appearance of a whistle under the hood of a car. The fact is that when moisture gets on the alternator belt, the frictional ability decreases and, accordingly, a whistle appears.
Grease. In addition to moisture, the cause of belt whistling may be difficult turning of the alternator pulley due to the fact that the grease in the alternator bearing may thicken. But it is important to remember that this problem manifests itself when starting the engine on a cold one.
Belt tensioners not adjusted. It is also worth mentioning the weak tension of the alternator belt. With a weak tension, the belt slips along the pulley, which causes the appearance of a characteristic whistle. Below you can hear how the alternator belt whistles.
Lack of lubricant in bearings. An equally common problem is the whistling of bearings and rollers. In the absence of lubrication, a characteristic whistle also appears on the rubbing surfaces of the bearing, but as mentioned earlier, this sound will differ from the familiar whistle of the alternator belt. This sound can even be called not a whistle, but a full-fledged rumble. Below you can hear how the generator bearing squeaks.
The drive of the water pump is very similar to the sound emitted by the generator belt. Therefore, in this case, it is necessary to have a clear ear to determine the specific location of the whistle. How the pump whistles can be heard below.
Conclusion.
From all of the above, it is important to conclude that the appearance of a whistle in the engine compartment, whether during acceleration or idling, is in any case an alarm signal, although in most cases it is not critical. But still it requires attention, search for causes, adjustments or replacement of individual elements. And you should not eliminate whistles and squeaks with various liquids or oils. This will eliminate the sound, but will not fix the problem.
Causes and culprits of whistling in the engine compartment was last modified: October 3rd, 2018 by Administrator
The article describes the causes and ways to eliminate the whistle of the alternator belt on cars Lanos, Priora, Kalina, Lancer 9, Renault Logan and other cars in the cold, in the rain and under loads.
First sign
Many car owners have an unpleasant situation when a loud and very unpleasant whistle is heard from under the hood. Moreover, it can occur at a variety of times - when starting the engine, while driving, in winter, in rainy weather, and so on.
The time of an unpleasant sound can vary from a few seconds to a constant while the power plant is running.
Almost always, the reason for this phenomenon lies in the belt drive, which drives the generator.
In many cars, the alternator belt additionally ensures the operation of a number of equipment - a hydraulic booster, an air conditioning compressor. Therefore, this belt drive is already called the "auxiliary equipment drive", although in the old fashioned way everyone calls it a generator belt.
The resulting whistle is not only unpleasant to perceive, as a rule, this is not the problem. A nasty sound is a signal of problems.
Many attribute everything to the belt drive itself, although this may indicate other malfunctions.
Attachment belt drive
The belt drive for driving attachments, the main of which is the generator, is used for good reason.
No other type of gear will have as many advantages as a belt.
And the benefits are as follows:
- Cheapness of the drive;
- The ability to transmit force over a distance without auxiliary elements (although in some cases a tension roller is still used);
- Flexibility, which allows you to transfer force to several devices at once;
- Comparatively long service life with minimal maintenance.
In practice, it has been proven that a belt as a drive is the best option, and if the conditions for its operation are met, then the belt drive also ensures noiseless operation.
But any violation leads to the appearance of a whistle under the hood. Although the problem does not always lie precisely in the belt, but most drivers, as practice shows, "sin" on it.
The peculiarity of the belt drive is that the force is transmitted due to the friction forces that occur between the working surfaces of the belt and pulleys.
To ensure this friction, the drive element must be properly tensioned.
The main causes of whistling
Belt tension.
If the tension is insufficient, then the belt slips along the surface of the pulley, which causes a squeal.
But it often happens that after an additional stretch, the sound does not disappear, on the contrary, it can even increase. And in this case, the problem is clearly elsewhere.
Deterioration of the generator drive.
The second of the main reasons for the whistle of the alternator belt lies in its strong wear.
Stratification, cracks and chipped areas affect the tightness of the contact surface of the drive to the pulleys, which is why slip occurs.
The ingress of technical fluids (primarily oils) also affects the friction between the working surfaces.
In addition to these problems, the drive may squeal for other reasons:
The sound is heard on cold start.
Most often this is due to poor-quality material for the manufacture of the alternator belt or its natural wear and tear - “aging”.
For normal transmission of force, the belt must have good elasticity. But if hard rubber was used for manufacturing, then due to excessive hardness, it will not properly “stick” to the surface of the pulleys, but slip along it.
The same result is given by the "aging" of rubber, it "dube", losing elasticity.
The reason may also lie in the bearings of the assemblies that the belt drives, especially at low temperatures.
This is because the grease in the bearings freezes due to frost, which increases the resistance to rotation, causing the belt to slip over the pulley.
Squealing appears when creating a load on the on-board network or when additional equipment (air conditioning) is turned on.
The reason lies in the same low-quality material of manufacture, loss of elasticity, development of working surfaces.
If the alternator belt whistle appears only when certain equipment is turned on, then this indicates a malfunction of the bearings of this assembly.
Rainy weather.
If the sound appears in rainy weather or in high humidity, then this is often the cause of insufficient tension.
As a result, the moisture that has settled on the belt reduces the friction force between the pulley and the drive, and the latter begins to slip.
Other reasons.
For example, on older VAZ models, a V-belt is used, in which the side surfaces are the workers.
So, if the pulley groove is heavily worked out, then the belt will sag more into it, because of this, the contact area of the surfaces decreases and it is easier for the belt to slip.
In multi-ribbed belts, this problem is not relevant, but there are other nuances in such a drive.
What can give a screech on different cars?
Daewoo Lanos.
For example, in Daewoo Lanos, the belt drives only the generator. That is, in most cases, the drive element itself becomes the cause of the squeal.
But sometimes there is such a problem as a violation of the position of the pulleys or a slight misalignment of one of them (most often a generator, due to bearing wear).
And because of this, unpleasant sounds will be made under the hood. Therefore, if everything is in order with the alternator belt, then you should pay attention to the pulleys.
Lada "Priora" and "Kalina".
These brands of cars have different types of power plants.
At the same time, the configuration of the generator drive and attachments (if any) is also different.
But in any version of the motor, in order to ensure the proper tension of the drive, the design has a tension roller. And if the cause of the whistle is not in the belt, then the next element that should be checked is the tension roller.
The drive of auxiliary units on the car Lada "Priora".
Mitsubishi Lancer 9.
This car has another problem, the power steering pump, which is powered by a belt and is almost flush with the alternator pulley, while there is no drive protection.
As a result of a not very successful design solution, dirt and moisture get on the working surface of the belt during operation, which causes slippage.
And it is almost impossible to solve such a problem, therefore, a short-term belt squeal in such a car is considered a “disease”.
Other car brands
But in Renault Logan, the causes of the whistle of the alternator belt do not differ from Priora and Kalina, that is, the problem usually lies either in the belt itself or in the tensioning mechanism.
What can be done?
As you can see, the main reason lies in the drive element itself. Therefore, when third-party sharp sounds appear, it is necessary:
You can do the listed work yourself, but if you have any difficulties with self-repair, compare on https://autoreshenie.ru/zamena-remnya-generatora-711/ the prices for replacing the generator belt among all car services in Moscow, read the reviews on them and pick the closest one!
Many car owners note that unpleasant third-party sounds appear only under certain conditions or after replacing the drive element. It is noted that the belt tension is normal, but there is a whistle.
The reason for this is usually the poor quality of the product and its increased hardness.
To solve the problem, you can use two methods - change the alternator belt to a quality one or try to process it with tools.
Such, for example, are silicone lubricant in the form of a spray for processing rubber elements and Hi-Gear conditioner.
The use of these means leads to an increase in elasticity and "sticking" of the drive to the pulleys.
But the use of WD-40 for these purposes is not recommended. The composition of this spray contains petroleum products, which can have a negative effect on rubber and lead to its rapid "aging".
Such processing can really help eliminate squeals under the hood, but only for a while, and after a certain period they will return again. Therefore, only will help to get rid of third-party sounds for a long time.
Possible consequences
Finally, we note the consequences that belt slippage, accompanied by a loud and unpleasant sound, can lead to.
Firstly, belt wear increases, because when slipping, it rubs against the pulley and heats up.