Knowing how the cooling system works helps you diagnose problems. In short, coolant collects heat as it passes through the engine and releases heat when it goes in the radiator. Cooling devices mainly circulate antifreeze, contain it or control its temperature. Troubleshoot the cooling system in a VW Jetta by regularly inspecting cooling system devices. Join a mechanic for the following steps that apply to most model years.
Instructions
1. Inspect the water pump for leaks. Your water pump keeps coolant moving through the heater core, radiator and engine. A slight smell of antifreeze or spots of coolant under your Jetta when parked for a short period are signs of a faulty water pump.
2. Check hoses for leaks, cracks, dryness or collapses. This includes upper and lower radiator hoses, heater and bypass hoses and manifold coolant hoses. The upper hoses, for instance, measure about 2 inches wide and transport coolant between the radiator and engine. A damaged hose causes cooling system problems.
3. Examine your antifreeze level. Low coolant can lead to overheating. With low levels, put antifreeze in the expansion tank reservoir. Add extended life antifreeze recommended for 5 years or 150,000 miles to the reservoir. This goes for the four-cylinder and six-cylinder engines.
4. Remove the antifreeze and flush the system to troubleshoot cooling problems. Make sure to dispose of coolant properly because the brightly colored sweet smelling liquid attracts animals and small children. Ingesting it can be fatal.
5. Look at the radiator cap to see if it is faulty. A damaged cap might be eroded or contain corrosion. Get a mechanic to use a pressure tester or an adapter to examine the cap's pressure rating and operation. Replace a defective cap promptly.
6. Wash and rinse the front of your radiator because dirt, rocks, leaves and other debris suck into the vents of your radiator when driving. This leads to overheating. Use a soft nylon brush, soapy water and a water hose to clean your radiator front.
7. Test the thermostat to see if it is sticking. Identify a stuck thermostat with constant low temperature readings or peaks between high and normal temperatures. Usually you can locate your thermostat inside the housing on the engine side of the upper radiator hose.
Tags: troubleshoot, cooling, system, jetta, cooling system, water pump, your radiator, radiator engine
