In Summary

Hello Paul, lately, my Toyota Ipsum loses engine water and I have to top up every day. We have recently replaced the water pump but the problem persists. I have had to replace the timing belt in a short time because the new one broke again. What could be causing these two problems? Kisira.

Hello Paul, lately, my Toyota Ipsum loses engine water and I have to top up every day. We have recently replaced the water pump but the problem persists. I have had to replace the timing belt in a short time because the new one broke again. What could be causing these two problems? Kisira.

Hello Kisira, the engine cooling system and the timing system are different and independent of each other. However, it is possible for cooling system failure to affect the timing system, particularly the timing belt.
Briefly, the engine cooling system relies on the water pump to drive coolant fluid around the engine while the cooling fans and radiator help to lower the temperature of coolant which in turn cools the engine. A breakdown of any of these components will cause the engine to overheat which can lead to coolant leakage. When the engine overheats, it can also damage a new timing belt.
Other causes of engine coolant loss include a damaged cylinder head gasket, especially due to an overheating episode which will cause a leak of coolant fluid into the engine oil. Ask your mechanic to critically look at the condition of the engine oil to rule out cross flow contamination by coolant via the head gasket. In addition to a damaged water pump (which you renewed) a corrosion damaged engine block can also cause coolant leakage. Damaged or loose coolant hoses, a worn out radiator cap and a corrosion damaged radiator housing are also notorious for causing coolant leaks. Your mechanic should also check these out.
The timing belt (T belt) helps to synchronise the engine camshaft and crankshaft operation to achieve optimum ignition and combustion while avoiding collision of the valves and pistons. As such, it is close to the hottest part of the engine. If the engine tends to overheat the T belt is likely to fail prematurely. Other causes of premature damage of the T belt include failure to replace a worn out T belt tensioner and pulleys during the T belt replacement, leaking camshaft oil seals as well as use of a counterfeit poor quality timing belt.
Discuss these points with your mechanic and he should be able to pinpoint the cause of your current plight and resolve the two conditions.