The appearance of a characteristic metallic ringing in the front part of the power plant of a VAZ-2107 vehicle indicates problems with the gas distribution mechanism drive.
The cause of this ringing is the weakening of the drive chain as a result of its strong stretching or weak tension by the tensioner.
And if severe stretching of the chain can only be eliminated by replacing it, then tensioning it is a procedure that is included in the list of maintenance work and must be carried out in a timely manner.
But there are also cases when the tension was recently carried out, the chain has not yet exhausted its service life, and ringing has already begun to appear.
This is often due to the chain tension mechanism.
Features of the tension mechanism and its possible malfunctions
Tensioner is a drive element that provides a certain tension to the timing chain.
The “native” device of this car is a plunger type. That is, in the design of this element there is a spring-loaded plunger, which, due to the pressure of the spring, provides the necessary tension.
This element works in this way - the spring pushes the plunger out of the body, it rests on the shoe and pushes it until the plunger stops the resistance of the chain, while the slack is removed from it by a powerful tensioner spring, the chain is tensioned.
But its design is such that after taking out the slack in the chain, the plunger is fixed with a cracker.
However, over time, the chain stretches more and more and its additional tension is required, for which it is necessary to remove the lock nut fixation of the plunger with a cap nut so that the spring makes a selection again.
One of the main disadvantages of such a tensioner is the possibility of debris getting between the plunger and the body, which can cause it to jam.
Sometimes jamming can be eliminated by lightly tapping the body, but not always. Damage to the housing always leads to the need to replace it.
It is not always convenient to periodically sample chain slack, so instead of a standard tensioner, you can install an automatic one, which performs the sampling itself.
At the same time, the design of such a tension mechanism is very simple and the possibility of jamming is practically excluded.
Consequences of a loose chain on a VAZ 2107
This applies to 2106 and all classics in general. First of all, the chain is manufactured with high precision and durability. This means that at the slightest jump of teeth, the engine will work at random. This is especially true for injection engines, since the crankshaft position sensor will give one reading, but in fact, the shaft will be in a completely different position. Moreover, jumping two or more teeth is fraught with the risk that the valve will punch a hole in the piston, and such a disaster will occur in all cylinders, and if, when the belt breaks, for example, the timing parts move simply by inertia, then in this situation they are still driven into movement from the crankshaft.
Automatic tensioner, design, operating principle
The automatic mechanism uses a ratchet mechanism, which itself takes out the slack of the chain as it stretches.
This element consists of a housing in which a spring-loaded ratchet pawl is installed.
Inside the housing there is a spring and a tensioner rod with a toothed sector.
The sector teeth are small, have a pitch of 1 mm, and are inclined in a certain direction.
This is how an automatic tensioner works.
As the chain sag, the spring pushes the rod and it, acting on the shoe, makes a selection.
But the pawl of the ratchet mechanism, which places one of its ends between the teeth of the sector, prevents the rod from returning back.
As the chain stretches, the rod moves out, and the pawl, jumping over the teeth, prevents it from returning back. Thus, the tensioner constantly maintains chain tension.
If it is discovered that the standard tensioner has ceased to perform its functions due to damage or jamming, which could not be eliminated by tapping the body, then it must be replaced.
This operation can be divided into partial, when only the damaged element is replaced, and complete, in which the shoe is also replaced.
Why is this so important to do?
During operation, the chain is subjected to significant loads. After all, it interacts with two shafts - the crankshaft and the camshaft. Over time, the part stretches out. The chain pitch changes and the engine begins to operate unstably. As a result, the revolutions fluctuate, and the mechanism itself jumps one or more teeth. If the circuit begins to make noise, this is the first sign for diagnosis.
Experts recommend tightening the chain every 15 thousand kilometers. Its resource itself is about 100 thousand. By this time the part must be replaced. The sedative also changes. Before tensioning the chain on the VAZ-2107, check its condition. All the necessary elements can be found in the VAZ-2107 timing belt repair kit.
Removing the mechanism
The car is placed on a level surface and immobilized with the handbrake.
To partially replace the tensioning mechanism, you do not need to remove anything from the engine. It is enough to unscrew the two nuts securing this element and remove it.
You need to pull it out carefully so as not to damage the gasket located under it.
But if this one came complete with a new tensioner, then it is not necessary to monitor the safety of the old one.
Signs of stretching
The symptoms of this problem are specific. And it will be very difficult to confuse them with something else.
In some cases, the damper breaks. In this case, only replacing it will help. How to tension a chain on a VAZ-2107 (injector)? Photos of the process are in our article.
By the way, on a VAZ-2107 with a carburetor power system, unlike injection engines, to turn the crankshaft it is enough to turn the ratchet. But let’s not get ahead of ourselves and consider several ways to tighten the motor chain on a VAZ-2107.
Installing a new element
Before installing a new tensioner, if it is a plunger tensioner, it must be “charged”. This concept hides the need to completely insert the plunger into the housing before installation.
To do this, the new element is clamped in a vice, but so that it does not damage the body.
Then use a 13 key to loosen the cap nut, and the plunger will come out of the body under the action of a spring.
Next, the tensioner is removed from the vice. Then, holding it by the mounting ears with your hand, you need to rest the plunger against a hard surface and press on it so that it goes into the body.
While holding it in this position, tighten the cap nut to secure the plunger.
Afterwards, the “charged” tensioning mechanism is installed in place and secured with two nuts.
In order for the tensioner to operate and extract, you need to loosen the cap nut again, after which you will hear a click indicating that the plunger has come out and extracted.
Adjustment Details
Sometimes the process of adjusting the tension level may be required several times. Therefore, let us consider in detail how this procedure is performed. After the cover has been removed, it is necessary to relieve the pressure in the tensioner. To do this, unscrew the corresponding lock nut.
How to tension a chain on a VAZ-2107? Use a large wrench to turn the crankshaft. It should stop at the point of greatest resistance. Just turn it a couple of turns. Using a wrench, fix the shaft in this position and tighten the cap nut. How to further tighten the chain on the VAZ-2107 with your own hands?
We connect the tensioner and check how secure it is. If the chain is elastic, install all the elements in place and start the engine. When checking the operation of the timing drive, there should be no extraneous noise, which will increase with increasing crankshaft speed.
Features of replacing the tensioner shoe
If a complete replacement is made, along with the shoe, then the operation becomes much more complicated.
The entire sequence of work to remove the shoe is described here.
In short, in addition to removing the tension mechanism, you will also need to dismantle the drive pulleys in the front part of the engine, the drive cover, the camshaft sprockets and the auxiliary shaft.
Only then will it be possible to remove the shoe for replacement.
Most VAZ-2107 cars were equipped with a carburetor power system.
But the latest models came with an injector. Although the sequence of replacing the timing chain tensioner does not change.
How to understand that you need to pay attention to the timing assembly
Timing chain problems manifest themselves in a variety of ways.
In some cases, the power unit begins to triple, and in others, at idle you can hear floating speed. In advanced cases, a carburetor or injection VAZ-2107 can simply stall, and some modifications completely fail when the chain jumps. Other symptoms may include:
- an increase in temperature in the cylinder-piston group (leads to accelerated wear of its parts);
- a metallic ringing sound coming from the front engine cover;
- knocking noise from under the valve covers;
- Belt tension does not eliminate extraneous noise.
We recommend that you do not delay repairs if you hear the first signs of incorrect engine operation.
Auto mechanics recommend regularly checking the timing belt tension to detect problems at an early stage. You also need to pay attention to the condition of the shoe; if it is worn out, then you should not delay repairs.
When to check chain tension
If you need to tighten the chain, it is not necessary to check the tension. It is enough to use a chain tensioner (this will be discussed below). Checking the tension is necessary if the chain has been replaced or if the chain continues to knock after tensioning. The knock of a loose chain is easy to distinguish from other noises: when the engine speed increases, it disappears.
To check this yourself, you need to open the hood and start the car. Then ask an assistant to press the gas pedal or independently pull the cable that controls the throttle valve with your hand. If the knocking noise at the front of the engine has disappeared, the cause is low chain tension. It needs to be tightened up.
How to check chain tension
The VAZ 2107 timing chain is located in the front part of the engine. It is closed on top by the cylinder head cover, on the bottom by the engine sump, the middle part runs inside the block and can only be reached by removing the chain.
To check the chain tension, simply remove the cylinder head cover. To do this, you need to unscrew the 8 fastening nuts. After removing the cover, the gasket must be replaced. It is inexpensive, but if this is not done, after installing the cover with the old gasket, it is almost guaranteed that oil will begin to ooze from under it.
When the "valve cover" is removed, the top of the chain is exposed. You can check the tension with your hands, but it is better to use a large screwdriver. It must be inserted between the chain and the cylinder block body and, using it as a lever, try to bend the chain. In this case, the chain should not bend. The tension must be checked on both sides - on the left and right sides of the engine. A chain that is taut like a string and does not bend when pressed with a screwdriver or fingers is a sign of its correct tension. Otherwise, it must be tightened or replaced.
Important: Do not apply too much force by pressing the chain as hard as you can. This can lead to deformation of the chain links. Therefore, it is necessary to press “half-heartedly.”
