In the process of operating the car, the motorist has to face various problems that arise with his car. One of these is a valve cover leak. We will talk about why it occurs and how to eliminate it in this article.
Valve cover and seal
Any driver who sees what is under the hood of his car is aware of the location of the valve cover. It protects the mechanism, closing it from external influences. In addition, protection against oil leakage is provided. The element is attached to the cylinder head by means of bolts and a special gasket cut to fit the shape of the head and cover.
Sufficient tightness depends on it. The unsatisfactory condition of the gasket is indicated by an oil leak. And in this case, it will need to be replaced.
However, before proceeding with the repair, you need to understand the reasons that led to the depressurization of the part, since otherwise the seal will have to be replaced again and again.
Valve cover oil
The cause of any leakage of lubricating fluid, no matter where the connection of the motor elements occurs, is mainly due to poor crankcase ventilation. This can be not only a valve cover, but also a gas pump, and a distributor, and more.
During operation, a part of the exhaust gases breaks out from any piston; they leak through its seal into the engine crankcase. If the power unit is new, then the amount of leaked gases will be minimal. But with a good range of exhaust gases , a lot is accumulated in the crankcase, and in the end, overpressure forms and the valve cover flows. To reduce it, new cars have an additional ventilation system designed specifically for the crankcase.
Crankcase ventilation
Gasoline power units are equipped with two types of ventilation: for idling and for working at high speeds. Both systems consist of rubber tubes, due to which gases are sucked into the intake manifold. Such a valve closes the system at idle. If it does not function, then this will cause a very poor mixture to form in the intake manifold. As a result, the motor will start to shake or, worse, stall.
In order to prevent crankcase gases from escaping with oil dust, an oil separator is installed in the valve cover. It can clog up with soot and not work. Then the oil will penetrate the intake manifold through the filter, which will cause, of course, engine smoke.
The engine equipped with an injection has one gas exhaust pipe, but closer to the throttle the channel is divided into two. The one that has a larger diameter enters the collector right up to the damper, and the smaller one, which is usually clogged with slag, after it. Through this channel of smaller diameter ventilation at idle is realized, and through the second when the shutter is open. If the channels are contaminated and ventilation is not carried out, then the exhaust will generate so much excess pressure in the motor that it will not be able to withstand either gaskets or gaskets. This is why crankcase gases begin to flow out.
If it is discovered that the valve cover is leaking, before repairing the breakdown, it is necessary to restore the ventilation system so that even after a thousand revolutions the cardboard on the valve cover can be pressed tightly against it. After all, with a worn-out mechanism this cannot be obtained even at two thousand revolutions, because the exhaust will break into the crankcase, and the oil flow will continue again and again.
Lid flushing
If the valve cover is sweating, it is removed and washed, and the seal is changed. You may be surprised at the result. The main thing is not to forget about the lubrication of the washer and bolts with which the valve cover is fixed. When washing, try to completely wash the oil separator so that the mesh in it is at least slightly cleaned. When installing the cover back and tightening the nuts, be careful not to break the threads or crush the part.
16V
On the other hand, if you constantly maintain the oil level by regularly adding it, then there is nothing to worry about when the oil leaks from under the valve cover. But with a 16V motor installed, for example, on a Lacetti, in which the candles are in the recesses, this malfunction can result in failure of the ignition system. Therefore, the valve cover "Lacetti" in this case must be removed, and the leak must be fixed.
Gasket replacement
To replace the gasket, you need to take care in advance of the availability of all components, that is, a new gasket, sealant and degreaser.
Replacement is carried out on a cold motor, so as not to get burns and injuries due to hot parts.
The procedure is as follows:
- The car is driven into a garage or on a regular flat area, open the hood.
- Remove the filter cover and unscrew the bolts.
- Remove the remaining fasteners and the cover itself from the cylinder head.
- The compounds of the elements are cleaned of the existing seal and degreased.
- They process a new part with a sealing agent and mount in the reverse order.
After the replacement is made, the head must be wiped and the motor started. If a leak is detected again immediately, most likely the gasket or sealant turned out to be of poor quality or the installation was carried out in the wrong sequence.
To avoid negative consequences, all parts, including the Opel Astra valve cover G, on which the aforementioned 16V engine is mounted, gaskets, sealants and everything else, must be purchased at trustworthy auto parts stores.