Radiator (engine cooler) for your car

Your Radiator (engine cooler) worn out? » Read more about common malfunctions • Repair • Replacement manual

The radiator is a critical component of the cooling circuit, responsible for maintaining the engine temperature at constant level and preventing damage through overheating. Driving around with a defective radiator means risking heavy damage to the engine. Therefore this spare part must be replaced as soon as possible.

The radiator in an overview:

Where is this component situated?

• Right up front in the engine compartment behind the fan and the radiator grille

How does it function?

• At the inlet, the coolant heated by the engine is pumped in.
• It flows through meandering pipes in a network of cooling ribs.
• Depending on type, a cross-flow or a down draft of cold air is blown over the cooling ribs.
• On the outlet side the cooled coolant leaves the radiator, flowing into the next component of the cooling circuit.

What happens in case of defect?

• When the radiator is leaking, it loses coolant. Other factors can impair its functioning as well. The result is an imminent overheating of the engine, which can in extreme cases lead to total damage.

Possible causes

• Causes for defects can be of mechanical or chemical nature.
• Gradually dissolution of joining connections leads to leakages.
• Mechanical stress causes holes in cooling ribs and piping.
• Chemical deposits (lime scale) cause a declining cooling performance.
• Rust can destroy the surface and cause holes.

To the garage or DIY replacement?

• In most cases the radiator can be replaced by a layman without any problem. Just a few steps, a wrench for the piping and a screwdriver are necessary for this repair.

Tips for radiator replacement:

1. Start by pulling out the fan plugs. 2. Then disconnect the water hoses (pipes). Collect the draining coolant in a bowl. 3. Loosen the screws of the air baffle plate, lever out the upper bracket and carefully remove the radiator. Installing the spare part, act in the reverse order. 4. After installation of a new radiator, the system must be vented. Unscrew the expansion tank and start the engine. Turn on the heat and ventilation full-blast and wait until the large cooling circuit opens. Meanwhile check connections if they are properly sealed.

Differences between spare parts

Nowadays three different radiators are used more or less frequently. The cheapest and most frequently used is the brass radiator. Lead-soldered, flat pipes and curved slats are soldered together. The amount of flat pipes is determined by the height of the component. These radiators are rather heavy and large and have an acceptable cooling performance at most. In composite radiators, pipes are oval and the ribs are inserted or stamped on. Connections are made by extension and addition. This radiator involves more work, but carries less material, saving weight. The cooling performance is a fraction better than the brass variant. More expensive cars generally have an aluminium radiator which can be purchased as a spare part for older cars as well. This type only brings advantages: especially the 15% lower weight, but also the higher temperature resistance up to 650ᵒC as well as a natural protection against corrosion and chemical degradation. The only disadvantage is the relatively high price.

Avoiding damage: the right coolant and anti-freeze

Use of the right coolant and anti-freeze is important as only this offers adequate protection against corrosion and lime scale. The right agent for your radiator can be identified by the colour of the coolant or the data in your car manual. Blue and green agents contain silicates; red-coloured agents are silicate-free and specifically used for aluminium radiators. The blue agent can replace the blue agent in emergencies. Red and blue or red and green should however never be mixed.

What are the costs?

Mainly corrosion and lime scale affect your radiator and therefore a high chemical resistance guarantees a long life span. For aluminium radiators this is several decennia, whereas cheaper brass radiators already start to rust after several years. You can obtain these for less than 100 EUR (c. £90), although their life span will be correspondingly short. High-quality products can cost up to 300 EUR (c. £270). Those who regularly spend time on the motorway shouldn't be too thrifty and value quality instead. In our shop you find OEM-quality spare parts at considerably lower prices and if you make use of daily offers and price reductions, you can save a lot of money.