News Spotlight

The cooling system on a vehicle has one primary purpose — to remove excess combustion heat from the engine.

As combustion occurs, a portion of the energy that's created is converted into mechanical energy. The balance is converted into heat energy. Some of this heat energy is vented through the exhaust system; the rest is drawn away from the engine via a steady flow of regulated coolant.

If not removed, this heat, which can top 4,500°F, is enough to destroy an engine in as little as 30 minutes. The ideal engine operating temperature is regulated at approximately 200°F (100°C) ± 20°F (approximately 11°C).

If the engine coolant gets too hot, engine damage can occur. Conversely, if an engine operates at too low a temperature, engine performance can suffer. A cooling system malfunction in newer vehicles typically is associated with a single cause. As vehicles age and accumulate mileage, however, several factors can contribute to a malfunction, including:

Coolant Condition

Coolant is used to transfer heat in the system. The chemicals in coolant, when properly mixed with water, are formulated for maximum protection against boiling, freezing, rust and corrosion. All repairs should include a basic check of the coolant condition.

Leaks

Leaks not only contribute to coolant loss, but they also don't allow necessary coolant pressure to increase, thereby decreasing the coolant's boiling point. Inspect hoses, connections and components to be certain all are in good condition. Keep in mind that not all coolant leaks are external. Leaks in the combustion chamber can cause hot gasses to be forced into the cooling system.

Thermostat Failures

The thermostat regulates both coolant flow and system temperatures. Without it, coolant would flow too fast past the combustion chamber, leaving damaging heat inside the engine. When a thermostat fails, it does so in an open or closed position. If stuck open, the engine has trouble reaching its ideal operating temperature. If stuck closed, the engine quickly overheats.

Radiator Problems

Inspect the exterior of the radiator carefully. Look for obstructions that can restrict airflow. Also check inside the radiator at the filler neck and inspect the inside of the radiator cap.

Corrosion and internal deposits can reduce coolant flow, affecting cooling system efficiency. Restrictions can be located with an infrared thermometer. They will appear as cold spots. Inspect the fins of the radiator for corrosion and the radiator tanks for developing cracks or deformations.

Restricted radiators should be flushed or replaced if the blockages can't be cleared.

Additionally, check the rubber insulator mounts for deterioration and cracks.

Broken or loose mountings subject the radiator to damaging vibrations.

Water Pump Concerns

Check the water pump drive for excessive side play. If the bearings are worn, replace the pump. Also inspect the housing for leaks from the seal, vent hole or mounting bolts.

Servicing cooling systems doesn't need to be difficult if a process of elimination is used.

Previous Repairs

Unfortunately, even minor mistakes made in previous repairs can have major consequences. Example: Electric fan replacement. Wires can easily be crossed, causing the fan to run backwards. Also, using replacement wire that is not to gauge (too thin), can cause the fan to turn too slowly, which leads to poor performance and premature failure.

Delphi Product & Service Solutions - Delphi's aftermarket division provides OE quality replacement parts for the right fit, form and function - the first time, every time. Delphi's OE heritage and automotive electronics expertise provides an extensive product portfolio for the independent aftermarket.

The Delphi aftermarket brand ensures that our customers can expect the same Delphi quality and expertise that vehicle manufacturers have always benefited from.

The products we market and distribute through traditional aftermarket channels cover domestic and import applications. In addition, Delphi offers the most advanced diagnostic tools in the industry as well as training and technical support to ensure all Delphi customers have the information they need, when they need it to compete in today's automotive aftermarket.