Can simple water lead to the repair of the car for hundreds of thousands of rubles? Yes, if it gets into the engine. After all, because of this, hydrostroke can occur, after which nothing good can be expected. We explain how water can get inside the engine and, most importantly, how to avoid it.
What is the danger of water hammer
The term “hydrostroke” is applicable only to the internal combustion engine. The principle of operation of internal combustion engines is based on the ignition of the fuel-air mixture in hermetically sealed (with closed valves) cylinders. You can read about it in detail in the Textbook. In order for the mixture to burn efficiently, the piston on one of the cycles compresses it by going upwards.
Gases are easy to compress, but if water gets into the cylinders, the task becomes impossible. Many people know from physics that liquids are practically incompressible, so it is easy to imagine even a small volume of water as a solid obstacle. The inertia of the crankshaft “pushes” the piston into this obstacle, which causes damage to the engine.
Their degree depends on many factors: engine speed at the moment of impact, as well as the amount of liquid. In the most fatal cases, the piston or connecting rod penetrates the wall of the cylinder block, and then major engine overhaul is inevitable.
How water gets in
The logical question is: where can water come from in the engine? As a rule, it gets there the only possible way – through the air intake. For example, if you decided to ford a ford and did not calculate the depth. Or during a rainstorm, the streets were flooded and you drove through them without slowing down.
Not every submergence of the air intake into water causes water hammer. The air filter resists, and if the water has risen above the critical point only for a moment, the filter paper will simply get wet, but fatal consequences will be avoided.
What to do if hydrostroke is suspected
In some cases, it is impossible not to notice it: from under the hood there is a strong metallic rumble. But everything happens much more modestly: the engine just quietly stops. Is it worth trying to continue driving?
No, first you need to find out the cause of the stoppage. Perhaps, the matter is not a hydrostroke at all – just flooded wiring (especially sensitive to moisture high-voltage parts of the ignition system) or the control unit. To make at least the first conclusions, it is enough to get to the air filter. In modern cars, it is not hidden deep, so it is easily accessible.
If the filter is wet, it is not good. Perhaps the water is inside and it is the reason for the engine stopping. Try to unscrew the plugs and look at the electrodes. In a serviceable engine, of course, they are dry (we are not interested in soot now). If the electrodes are wet, you will have to go to the service by tow truck or towing.
To finally understand the situation, you can turn the crankshaft with the starter when the plugs are unscrewed in all cylinders. Extraneous sounds and certainly the lack of rotation will confirm the negative predictions. But it also happens that there was no strong impact when water hit – for example, if the engine was running at idle speed. This is the most positive scenario. You can spin the crankshaft a few times – the excess moisture will come out through the plug holes and valves, then wrap the plugs and try to start the engine.
How to avoid hydrostroke
The advice is obvious: don’t drive into fords or deep puddles. But how do you know the limit that can safely force a particular car?
It all depends on where exactly the air intake is located. You have probably seen brutal jeeps with plastic pipes at the hood and front racks – these are snorkels, which allow you to move the air intake as high as possible. In normal city cars, the intake hole is under the fender at various heights or closer to the top of the underhood. You can try to see it by removing the plastic shield on the motor (if there is one). Alternatively, just ask at the service where exactly your air intake is located.
Keep in mind that when the car moves through the water, a wave is formed, that is, the level rises. If the depth of a ford or puddle is at least close to the height of the air intake, it is better not to force such an obstacle.
Summary of results
- Hydro shock is an attempt by the pistons to compress the water that has entered the cylinders.
- The severity of the consequences of hydrostroke depends on the speed of rotation of the crankshaft at the fatal moment and on the amount of water trapped inside.
- Rarely, but still happens that the meeting of the piston with water passes without devastating consequences.
- The main rule that will save your engine is not to drive into bodies of water as deep as the height of your air intake.