Driving through water could kill engine

H. Kishie Singh

The rains in Chandigarh have set new records. In some places water was waist high. Common sense should have told you to stay at home. If you were forced to venture out, you should have driven with extreme caution. But, no. People drove through flooded roads, even though water flowed over their bonnets. What fun! And many people came to grief, judging by the number of phone calls and emails I received. 

Not only was I asked what had gone wrong with their cars, I was also asked if insurance would cover the damage to their cars. How on earth could I possibly know the terms and conditions of their insurance policy? Please read the fine print of your insurance policy. And if you don’t know how to drive on water logged roads, stay at home and watch the fun on TV. You decided to have fun on the streets. You went full steam ahead, wipers on fast, water flowing over your bonnet and the engine spluttered, choked, sighed and died! No surprise here. Water had been ingested into the engine via the air intake. This condition is referred to as hydrostatic lock.

The natural reflex will be to try and start the engine. Do not attempt to restart the car. For sure you will kill the engine if you have not done it so far. More on this later.

At times like these, there are dozens of street urchins having fun splashing in the water. They will offer to push you to safety and then help you push start the car. Do not push-start the car.

Here is why. Your engine needs a mixture of fuel and air, which is injected into the combustion chamber. This is the suction stroke, the first in a 4 stroke engine. The next stroke is the compression stroke. This means that the piston has to move upwards to compress the fuel-air mixture.

Water has now entered the combustion chamber. Air can be compressed, water cannot be compressed. The piston comes against the water, the water won’t compress, but the connecting rod would push the piston and bend in the process. End of engine!

Till this point, the insurance company may consider this as a natural calamity and may entertain your claim. I say may. Was this natural calamity clause in the terms and conditions of your policy? If the answer is yes, you will get your claim. However, if you attempt to crank-start or push-start your car that will be another story.

More damage will be caused to the engine. The insurance company will put this down to consequential damage i.e. damage not caused by a natural calamity, but as a result of your negligence. The minute your engine died, you should have called it quits.

So far, had you been lucky, only one cylinder, piston and connecting rod would have been damaged. But any attempt to resuscitate the engine would have caused more damage. Which is why, I insist, do not attempt to restart the car. An engine rebuild for an aam aadmi car should be around Rs 40,000. For a high-end luxury car, the cost would be the price of an aam aadmi car!

If you want a water tight (pun not intended!) policy, add a rider to your present policy called ‘Engine Protection Cover’. It should cover hydrostatic-lock, whether by natural calamity or by negligence.

Happy Motoring!