Your car, truck or SUV has many systems with many moving parts. When they are all new, everything works quietly and smoothly. But over time, and with many kilometres of mileage, key components start to run out of life and risk causing malfunctions.
When a part goes down, you can hear all sorts of unpleasant sounds – squeaking, rattling and more – which directly points to the problem. The sounds coming from your car can be caused by a lot of problems. You can hear them when you’re slowing down, when you’re speeding up or just traveling on the road, when the car is idling, or after the engine starts. It is especially bad if such sounds come from the engine – the heart of the car.
Knock in the engine on blanks
If you’re a longtime driver, you’re probably in a situation where you start your car early in the morning and you’re looking forward to a long (or not) trip to work. But suddenly at idling speed you start to hear unpleasant sounds from the engine. And now what to do? Of course, you have two options.
The first one is to turn to the help of a qualified specialist from the service center, who will be able to make a qualitative diagnosis of the car. The second is to try to identify the source of the problem on your own. So you can not only save money on diagnostics, but also increase your ego as a real motorist). So, how to determine the cause of engine knocking at idle speed.
The first thing you need to do is to check the oil level sensor after the engine has warmed up to operating temperature. If you notice that the oil level has dropped, then you are definitely having problems. Also, gasify the engine. If the sound has only increased at high revolutions, then you will definitely need to start repairing the engine as soon as possible.
It is also a common cause of knocking in the engine that the valves are also the cause of knocking. Any driver, even with a little experience knows that the valves will “close” after you travel a certain number of kilometers
The main causes of the valve knocking are:
- camshaft problems
- valve rocker wear
- Poor oil supply through the channels in the camshaft.
According to the car mechanics, the most common cause of valve knocks is to increase the clearance between the camshaft levers and camshafts. It is clear that the bigger the gap, the louder you will hear the knocking. Of course, if you hear the knocking of the valves, it doesn’t mean you have to stop and call the tow truck.
But you shouldn’t allow the knocking to become very strong, because in this case the repair can cause you a very round sum. Again, service stations employees strongly recommend to check the condition of valves after every 15-20 thousand kilometers.
Knock on the crankshaft in the engine
The second common cause of motor knocking is problems with the camshaft. And there is a very important point: you need to understand exactly what causes the knocking – the camshaft or the valve.
The knocking of the valves can be distinguished from the knocking of the crankshaft by the nature of the knocking. The valves knock quite loudly, but the camshaft makes a deaf sound. In addition, the noise from the crankshaft starts to rattle right after the engine starts.
As you have already guessed, the knock of the crankshaft should not be ignored at all. In fact, this knocking means that the bearings and hydraulic compensator are suffering. Therefore, the longer you take to eliminate this noise, the more expensive it is to repair the engine itself. If you own a car that is not equipped with a hydraulic compensation system, then you can drive with a knock of the camshaft about 30 thousand km. But you do it at your own risk.
Main causes of camshaft knocking:
- Damage to the oil supply
- Fuel system problems
- Fist wear
- The wear and tear on the bed of the rampart.
Knock in the engine on the cold
The most important causes of engine knocking. However, there are other sources of engine knocking after a cold start. If you are sure that the cause of the knock is not a valve or camshaft, then the next candidate to start sinning is the cylinder block and piston group.
The reason for this knocking is that there is a gap on the cold engine when the gap between the bottom skirt of the piston and the cylinder wall allows the piston to swing slightly or have an additional free stroke. This allows the piston to hit the cylinder wall. As a result, you will hear a slightly dull tapping sound.
Another cause of the piston knocking is the so-called combustion chamber noise. The working body of the piston and the combustion chamber lid can accumulate a layer of carbon over time. When started cold, this carbon residue strikes, creating a deafening sound at the top of the piston stroke.
Knock in the engine on the hot
If we’ve dealt with the knocking of the engine on the cold, now it’s time to move on to the causes of the knocking of the engine, which has reached operating temperature. So, if you are faced with the fact that the engine has started knocking on hot, then the first thing you need to do is to check the oil level. If the oil level dipstick shows that the oil in the engine isn’t enough, then it needs to be refilled. After that, the knocking should stop.
If there is enough oil in the engine, then you should start looking at the crankshaft and valves obliquely. You can start blaming the crankshaft after the knock increases after the engine speed and temperature increases. As for the valves, as we have already written above, you will sooner or later face the knocking of the valves.
If you hear a thunderous knocking when you increase the number of engine revolutions, then it is the valve. Of course, you can continue to put up with it and continue driving the car, but it is better not to delay or aggravate the poor condition of the valves.
The engine is undoubtedly the heart of the car. Therefore, I do not want it to start making the wrong the main reasons for the knocking in the engine, depending on its temperature.