Thursday January 9 2014

What happens when you hit that pothole

By Farahani Mukisa

Have you ever considered how much money is spent on repairing your car as a result of it regularly hitting potholes? For starters, your car leaking problems could be attributed to that. It could also lead to your oil sumps getting broken, which will cost you some when it comes to repairs.

What is an oil sump?
The website describes an oil pan or sump as a component that typically seals the bottom side of four-stroke, internal combustion engines in automotive and other similar applications. Its main purpose is to form the bottommost part of the crankcase and to contain the engine oil before and after it has been circulated through the engine. The website goes on to state that during normal engine operation, an oil pump will draw oil from the pan and circulate it through the engine, where it is used to lubricate all the various components. After the oil has passed through the engine, it is allowed to return to the oil pan. In a wet sump system like this, the amount of oil that an engine can hold is directly related to the size of the oil pan. An engine can hold no more oil than can fit in the pan without reaching the crankshaft, since a submerged crankshaft will tend to aerate the oil, making it difficult or impossible for the oil pump to circulate it through the engine.

Potholes to blame
Because it is at the bottom end of the engine, the oil sump is exposed to being rubbed against humps and is also affected when cars hit potholes. Unfortunately, problems caused by potholes may be neglected because they may not affect the car’s movement. Bob Rubaniza, a consultant engineer at the Bukasa automotive garage, says for every 10 vehicles at their garage, eight usually have defects caused by potholes. “With many cars frequenting garages, this translates into profits. With vehicles subjected to hitting potholes, motorists end up paying a double price for the damages,” Rubaniza explains. He adds, “You find that a car that would visit a garage after every four months ends up visiting a garage every month because of potholes,” he observed.

Most affected parts
Christopher Obol, a mechanical engineering instructor at Nakawa Vocational Training Institute, says the suspension system is the most susceptible part, whenever a car hits a pothole. ¬The suspension of a car is actually part of the chassis, which comprises all of the important systems located beneath the car’s body.

How people are affected
Obol says that many owners of commercial vehicles such as commuter taxis that make frequent routes care less about the condition of their vehicles’ suspension systems. “But when these vans hit potholes, passengers tend to feel the impact, which means that the suspension systems of such taxis are either broken or damaged, hence they cannot reduce the discomfort that is associated with hitting potholes, combined with equally poor shock absorbers,” he notes. Obol says that owners of passenger cars such as Subaru Legacy among others whose oil sumps are really low, are prone to getting cracks in the oil sumps, upon hitting potholes, which will create leakages.

Advice to motorists
Rubaniza says that whenever driving on a potholed road, it is advisable to slow down to almost 0km/hr.