Timing belt is a relatively simple solution for actuating the timing mechanism and other equipment compared to the timing chain. At the same time the specified belt serves less than a chain, that is, it needs periodic replacement. Most drivers know, that when replacing the timing belt put on the labels drive pulleys, ??that is necessary for exact synchronization of work of the engine and the gas distribution mechanism.
We also recommend reading the article about it, why the compensator knocks. In this article you will learn about the causes of knocks on the hydrocommentators, as well as what to do to the driver, if the compensators started knocking.
However, not everyone knows to the end, how to properly set the timing belt for self-replacement and why it is so important. Let's note at once, that if the timing belt is not marked, then the gas distribution phases fail. As a result, the engine may not start after such a replacement, will work erratically or even break the engine. In this article we will talk about that, what are the symptoms of incorrectly set timing belt, and also how to expose a timing belt on labels or without them.
Why and when you need to change the timing belt
As you know, the timing shaft is based on the camshaft, which is located in the cylinder head and pushes the inlet / exhaust valves. The camshaft is driven from the crankshaft by means of a drive belt. Timely opening and closing of valves should be carried out in the strictly established order and according to measures of work of the engine.
In other words, the intake valve must open at the intake stroke, due to which air or fuel-air mixture enters the cylinders (depending on the type of engine). Next is the compression of the mixture (the piston moves in TDC), at this point all valves are closed. After ignition of a fuel charge and return of useful energy of the piston the final valve for removal of the fulfilled gases from the engine cylinder opens. This is how the gas distribution process takes place.
It becomes clear, that any malfunctions of the camshaft drive will lead to a violation of gas exchange in the cylinders, as a result, the engine will be disrupted. As for the timing belt, this element is a rubber product, which stretches over time, cracking, etc.. Slipping the belt leads to that, that the valves cease to open at a clearly defined moment in relation to the stroke of the motor. Moreover, for many engines the timing belt breakage is especially dangerous. The point is, what if the belt broke, then the timing mechanism stops, the valve simply does not have time to close until the piston rises, there is a blow, after which the valve wick is usually, there are defects in the piston, etc.. In such cases, the power unit must be repaired, and the repair itself will require significant financial costs.
Quite obviously, that taking into account these features, the timing belt has a limited service life. The specified element needs to be changed as on run, and over time. In the first case, manufacturers do not recommend exceeding the mark 60 thousand. Mileage or 4 years (depending on, which will come sooner). Further, experienced drivers prefer to carry out further replacement through 45-50 thousand. Km, since the quality of the first belt, installed at the factory, usually better than analogues or even original products.
A number of factors should also be considered, which can significantly reduce the service life of any belt. Example, hit of motor oil on a timing belt as a result of leak of a forward epiploon of a cranked shaft is capable to bring in unusability the specified element of a drive of a cam-shaft. Problems with the tension roller, pump jams and other malfunctions are the causes, for which the belt tears or wears out quickly.
We also recommend predicting an article about it, how to replace the front or rear crankshaft seal, if it flows. In this article, you will learn how to detect a leak, and also about features of replacement of epiploons.
If signs of wear of a timing belt are noticeable or the term of its planned replacement approaches, then it was not easy to install a new element. The belt must be set correctly during replacement. Tools must be prepared for replacement and display, it is also advisable to service the car on a lift or in a garage with a manhole. The minimum set for this operation can be considered a jack, screwdrivers, wrenches and sockets, socket wrench, it is desirable to have a collar with a cap head, etc..
Marking of a belt on labels and how to expose a timing belt without labels
Let's start with that, below we will focus on the general rules and recommendations, how to set the timing belt. This should be taken into account, that on cars with tuned sports camshafts, and also on some models with two or only one camshaft the order and features of exposure of a drive belt can differ. For more accurate information, it is advisable to consult with experts or separately study the manual for the operation of a particular model of internal combustion engine.
Remember before you start, that the important task is that, so that previously marked marks do not get lost during replacement. This will help simplify the process, as no further in-depth setup will be required.
- so, when installing a new timing belt, the responsible step is to set this position of the pistons in the engine, at which in the first cylinder the piston will be in the top dead center (TDC). Then the control of labels is carried out. Let's add, that you can put the pistons in the right position in one of the available ways. The easiest way to find a special notch on the pulley, as well as a pointer-arrow, located on the casing of the timing belt. The specified notch and arrow should be combined with each other. The combination implies such a state, when the notch is vertical, and the arrow is pointing down.
- Another way, which complements the first, there is a special mark on the flywheel, then the specified label is combined with the "tooth". The label is in the control window, which is made in the upper part of the bell of the checkpoint.
- The third and most unreliable way to expose the pistons is to turn the spark plug in the first cylinder, then a suitable screwdriver or steel rod of the desired length is inserted into the spark plug hole. Then the rod rests on the piston, then as a result of the return of the cloned determined point, in which the piston is in the uppermost position. pay attention, this method should be used only if, if tagging is not possible for any reason.
After installing a new belt to determine that, whether the labels have shifted, the end head with a rattle of a cranked shaft of the internal combustion engine turns a couple of times. Be sure to check next, whether the camshaft sprocket marks match. In that case, if the labels do not match, then it is necessary to achieve their complete coincidence.
Imagine, that the label "went" back relative to the camshaft sprocket. In this situation, the label is combined with the upper left edge of the valve cover gasket. If the label has moved forward and is marked "from", then the specified label is combined with the arrow, located behind the camshaft sprocket. If, when the camshaft mark is shifted by 180 degrees or so, then the crankshaft scrolls one turn.
Also note, that in the process of setting TDC in the first cylinder it is recommended to remove the cover of the shock absorber. This is necessary for that, to control the location of the notch on the body of the shock absorber. The notch should coincide with the center of the slider. To detect the notch, a plastic cover is slightly raised, covering the Hall sensor. When all the above tags match, this means, that you can install a new timing belt. Let's add, that before installation many also fix a flywheel, inserting a screwdriver into the hole of the box. After that you can put the belt and rollers.
Timing belt replacement
- The belt replacement process is, that in the beginning it is necessary to loosen fastening bolts of a pulley of a cranked shaft, after which the specified pulley is removed. Next is the removal of the dirt cover of the belt, before removing which it is recommended to fix the flywheel method, mentioned above. At the same time you need to remove the generator belt, water pump pulley. Removal of a belt of the generator occurs after loosening of bolts, mounting pump pulley.
- Then unscrew the timing belt tensioner roller bolt and remove the roller from the stud, on which it is fixed. Usually, the specified roller changes in parallel with each replacement of a timing belt. After removing the roller, the belt can also be removed.
- It is now possible to install a new tensioner roller and a new timing belt. The belt should also be tightened after installation. This is done automatically by means of a tension roller, sometimes lifting is done with a pump. The tension force itself is checked as follows, so that between the camshaft sprocket the belt can be twisted with the thumb and forefinger with little effort on 90 degrees, but no more. It is also worth considering, that the belt should not be sagging.
- After tensioning the belt you need to check the coincidence of the camshaft marks. In that case, if there is a slight deviation, the tension roller is loosened and the belt is rearranged. Then the video is fixed again, then turn the crankshaft bolt a couple of turns. Then all labels are checked again.
- In that case, if the crankshaft and camshaft marks match, but there is no coincidence of the marks of the shock absorber, then loosen the bolt, which fixes the shock absorber. Then the tumbler must be turned to this position, when the center of the slider and its labels match. This will help avoid this problem, When, example, when replacing the timing belt set late ignition, inflammation becomes early, etc..
As a result
With regard to belt-driven internal combustion engines should be taken into account, that slipping of a belt even on one "tooth" can lead to malfunctions of the power unit or its breakage. As mentioned above, if the belt breaks, there is a risk of bending the valves. As for diesel engines, Timing belt breakage can render the camshaft unusable.
It should be noted, what if the belt was set incorrectly, on the instrument panel after attempts to start the engine or during its operation in some cases the "check" lights up. Also, in the event of a severe label failure, the engine may not start. If the belt has not been exposed, but the engine still started, then the following signs may indicate an existing problem: the unit vibrates strongly after replacing the timing belt, there were knocks in the engine, slow or no timely ICE response to the accelerator pedal, increased fuel consumption, visible traces of accelerated wear of the belt itself.
Finally, I would like to add, that when replacing the timing belt, its labeling is a priority. In that case, if you are unsure or have trouble identifying labels, then it is better to abandon attempts to put the belt on their own and turn to experienced professionals.