So the worst has happened. Your 4X4 gets stranded in water, deep water. And the panic light is flashing in your brain. There are so many reasons why this could happen, but what you need to do first is to remember the safest way to save the engine. Of course, it is assumed that you have a buddy vehicle with you, which can fish your vehicle out of the water help in the recovery effort. What has to be done to get you back rolling again is what we will discuss here.
For petrol engines, as soon as the vehicle gets to dry land, immediately remove the spark and then crank the engine. Make sure that no one is immediately in front of spark plug holes because it can squirt out water, if there’s any, at very high pressure, it may hurt or injure someone.
Check the engine oil for water contamination. You will know if the oil is contaminated if its color turns like chocolate milk. If there is water mixed with the oil, have the oil replaced as soon as possible as water can corrode the cylinder liners once the engine has cooled down. Water will cause damage to the cylinder and pistons as well.
After expelling the water from the cylinder, re-install the spark plug and proceed with drying all electrical and electronic components of the engine. Computer controlled engines have a major disadvantage here, and how well the manufacturers have protected these components from water will depend on the limits they set for water fording. Hopefully, your engine should fire up and you will be on your way. If not, have your trail buddy tow you to the nearest competent mechanic that can get your vehicle rolling on its own power. Remember, if you have an automatic transmission, you can only tow your vehicle no more than eight kilometers. Should you need tow your vehicle farther than eight kilometers, you should disconnect the driveshafts and allow it to free-wheel. Not doing so will result in severe damage to the automatic transmission system.
Except for computer-controlled diesel engines, non-computer controlled diesels engines have a slight advantage in water-resistance because of the nature of diesels being compression engines and not needing a system to ignite fuel. So there is less electronics to worry about getting wet. However, it takes a very small amount of water to be ingested into the diesel engines to destroy the engine because of hydro-lock.
The procedure is the same with diesels in getting water out of the cylinders. Only in the diesel’s case, the fuel injectors need to be removed, or the engine glow plugs that preheat the diesel fuel before ignition. Extra care should be taken this time on the water squirting out, since diesel engines have a much higher compression ratio than petrol engines. It is assumed, of course, that anyone in this predicament has some tools and some basic knowledge of auto mechanicals. Don’t bother trying if you don’t know a thing about the engine, and just get a tow back because you may make things worse than they already are. Have the vehicle get a total check-up on all its lubricants and fluids as soon as possible and hope to get your 4X4 back on the trails again.