A Detailed Buying Guide for Buying Car Radiators on eBay

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A Detailed Buying Guide for Buying Car Radiators on eBay

The purpose of a car radiator is to circulate coolant through and around the engine to cool it through heat exchange. As the coolant in the radiator passes through the engine block, the coolant absorbs the heat of the engine. The coolant is then carried back to the radiator core where it is cooled and then fed back to the engine, where the whole process is repeated again and again. If a radiator fails, the car can quickly overheat and seize up.

It is important to remember that when searching for a replacement car radiator, the buyer needs to be aware of the make and model of the car, consider the type of the radiator, the construction materials, and whether the car radiator is new or used. eBay has a large selection of radiators to choose from. The site has an easy to use local search engine that makes searching for the right radiator for a car very straightforward.

What Is a Car Radiator?

A radiator cools a car's engine through heat exchange, preventing the car's engine from overheating. Radiator cores are made of stacked layers of sheet metal formed into channels and soldered or brazed together. Traditionally, radiators have been manufactured using brass or copper cores soldered to brass headers.

However, today's modern radiators are manufactured with plastic headers and aluminium cores. This type of construction means that modern radiators weigh considerably less, and the aluminium cores are much easier repair compared to cores made from traditional materials.

Types of Car Radiators

There are two primary types of radiators used to cool modern car engines: cross flow and down flow radiators. Both of these types of radiators have upper and lower tubes for cycling radiator fluids or antifreeze coolants through the cooling system. The heated radiator fluid enters the system through the top two tubes and then passes through a series of smaller, thinner tubes, and is cooled by cooler air before passing back into the car's engine through the two lower tubes.

Cross Flow Radiators

The main difference between cross flow radiators and down flow radiators is the location of the tanks that hold the coolant. Cross flow radiators are designed to use tanks that are located on the sides of the radiator core, allowing the coolant to cycle back and forth across the core.

The cross flow design allows heat to dissipate over a greater area when compared to the down flow design. The bonnet line is also lower on the cross flow radiator, making a cross flow radiator cheaper and easier to manufacture than a down flow radiator.

Down Flow Radiators

Down flow radiators have coolant tanks located above and below the radiator's core. This type of radiator has declined in popularity as most car manufacturers now favour the cross flow design. However, the design is still popular with manufacturers of heavy vehicles.

Down flow radiators have a conventional vertical-flow design with an expansion inlet tank located at the top of the core that connects a flexible hose to the coolant outlet housing on the engine. This setup allows coolant to circulate through the radiator. Automatic transmission vehicles have a heat exchanger or transmission oil cooler that allows automatic transmission fluid to circulate through for cooling.

When all is said and done, there is actually little difference between cross flow radiators and down flow radiators, other than the high bonnet line that is a noticeable feature of down flow radiators. The choice of a replacement car radiator comes down to what type of radiator is compatible with a particular make and model of car.

Radiator Caps and Coolant

Coolant is heated in a vehicle engine. This causes it to become less dense and to rise. As the radiator cools, the coolant becomes denser again and falls. Within the radiator, the coolant is under pressure that is higher than atmospheric pressures. This causes the coolant to have a lower boiling point. For this reason, calibrated pressure-relief valves are generally incorporated into the radiator's core. As the temperature, within the radiator increases, the coolant expands until the pressure relief valve opens and excess fluid is dumped into an overflow container. This process stops with the thermostat regulating the rate of cooling to keep the temperature within the radiator core at an optimum level.

If a cap is opened when the radiator is hot, there may be an immediate drop in system pressure, which can cause super-heated coolant to spray from the radiator opening and injuring anyone standing nearby. It is a good idea to buy a radiator that has a pressure relief valve that can be lifted to reduce internal pressure before it is fully removed.

How to Locate a Car Radiator on eBay

To start the search for a car radiator on eBay, the user simply has to type some descriptive keywords into the search bar on the home page. While a generic search query such as 'car radiator' is fine to start with, it is better to enter a more specific search query, as a search query that is too general results in the search engine returning thousands of listings for car radiators. To reduce the number of listings to a more manageable amount, eBay allows the user to employ a variety of search filters.

Results Page Search Filters

The buyer can narrow or expand their search options by using filters located on the results page. For example, the buyer can choose to search for radiators based on the make and model of the car, the condition of the car radiator (new or used), and the manufacturer. Besides specifying the features, the user can also sort the listings to only show local listings or to only show listings posted by eBay Top-Rated sellers.

Make and Model of Car

Radiators are not one-size-fits-all. The bonnet line, or profile, can vary from one radiator to the next. eBay takes the guesswork out of choosing a radiator for a particular car by allowing the buyer to filter the results based on the make and model of vehicle. If the user finds that their car is not listed, they need to do additional research. This may mean contacting a car dealership or the manufacturer directly.

Price of the Radiator

The buyer can also search for car radiators that fall within a specific price range by using the price filter on the results page. The user can set a maximum price as well as a minimum price, in pounds. This option allows the buyer to only see those listings that fall within their established budget and filter out those that are above or below the specified price range.

Condition of the Radiator

On eBay's results page, the buyer can choose to filter the results based on the condition of the radiator. For instance, the user can specify to only see listings for new radiators or used radiator. At times, the seller simply forgets to clarify the condition of the item listed for sale. If the buyer has the time, they should browse through the listing marked as 'Not specified'. This ensures that the buyer does not miss out on any great deals on car radiators.

Location and Distance

A buyer should consider any local listings for radiators posted by sellers that live nearby. This is to avoid hefty shipping charges. On the results page is the distance filter. The buyer simply needs to specify a search radius. She first needs to enter her postcode and then a search radius in miles. This is the distance the buyer is willing to travel to pick up the car radiator.

Part Manufacturer

eBay has a filter for sorting the listings based on the car radiator manufacturer, allowing the buyer to choose a radiator made by a specific company. With this filter, buyers can browse only those listings for radiators manufactured by brands they favour and trust.

Status of the Seller

A buyer should consider only doing business with an eBay Top-Rated Seller. Sellers that have earned this status are very knowledgable about the items they sell. They also have long histories of positive transactions on eBay. All sellers are rated according to the customer service they provide and the merchandise they sell. The scores add up to a feedback score and this score appears in the item listings. To only see those listing posted by eBay Top-Rated Sellers, the buyer needs to just select the appropriate search filter on the results page.


When buying a radiator for any car it is important for the buyer to do a bit of research to determine which model radiator is compatible with their car. While there are two types of radiators (cross flow and down flow), the buyer's choice is based on their make and model of car. As long as the buyer has this information, the buyer can search for a compatible radiator using eBay's search filter. Additionally, the buyer can sort the listing based on budget and the condition of the radiator. There are pros and cons for both new and used radiators, however, spending a bit more on a new radiator ensures that the car continues to perform well. The buyer can also search based on the location of the seller and whether the seller is rated as a Top-rated Seller. With a huge selection of car parts to choose from and an easy to use search engine, looking for a replacement car radiator is a snap with eBay.

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