Advertisement

The Plastic Radiator: How Cool Is That?

Share
TIMES STAFF WRITER

Question: My radiator recently failed. My mechanic said I sprang a leak in the radiator’s plastic tank, though I’m not sure what the tank is. But he said a lot of new cars (mine is a Ford) now use plastic radiators instead of copper.

This seems to me like just another cheesy cutback by auto companies. I ended up with a rebuilt radiator, which set me back $280. Why did the car companies stop making radiators out of copper? --J.L.

Answer: Copper is an amazing metal--nontoxic, remarkably resistant to corrosion, extraordinarily malleable and easily mended with solder. At one time, a good copper radiator would last the vehicle’s lifetime, provided it didn’t become clogged by a contaminated cooling system and the coolant was regularly changed to purge acids.

Advertisement

But, as with a lot of small things in this world that seem to work well enough to leave alone--nongenetically modified corn comes to mind--the copper radiator is being overtaken by plastic.

A lot of industries have tried to get rid of copper to save money. Electrical equipment manufacturers decided aluminum would be a good replacement for copper in household wiring a few decades ago, until a rash of household fires brought copper back.

Of course, the U.S. Mint long ago removed most of the copper from the penny, because the metal was worth more than the coin.

Auto makers have always pushed to wring every last penny of cost from their vehicles. And in recent years, they have also worked to rid vehicles of excess weight in a bid to improve fuel economy. Plastic radiators are both cheaper and lighter.

At the same time, radiators were made much smaller and with reduced coolant capacity, meaning that they had to be far more efficient with higher operating pressures and temperatures to cool the engine.

In short, auto makers forced a smaller plastic system to do more work at higher pressure than the older copper system.

Advertisement

Dave Gordon, technical director at the National Automotive Radiator Service Assn., swears that the plastic radiator is actually better than copper.

The problem with copper, Gordon says, is that it was always subject to deterioration at the soldered seams and elsewhere.

*

But plastic radiators have the same kind of problems.

The primary plastic parts are the tanks at either end of the radiator core, which is often made of aluminum and carries coolant through the cooling fins.

“An aluminum core is a very durable radiator that will hold up just as long as copper-brass,” Gordon said.

In a cross-flow radiator, the tanks are located on either side of the radiator (as the name implies, the coolant moves from side to side). In a down-flow radiator, the tanks are at the top and bottom.

Typically, when a plastic radiator fails, the tanks crack or the gasket that seals the tank to the core fails.

Advertisement

The fix is to replace the tanks and keep the core, although many garages simply replace the entire radiator with one that has already been rebuilt and then recycle the old core to a specialty radiator shop.

Plastic radiators and aluminum cores are generally far trickier than copper to repair. You cannot use low-temperature solder to fix them but instead must rely on expoxies, special welding or hot-melt adhesives.

Nobody buys an automobile, however, just because it has a copper radiator. Only a total gear head would even think to ask the question. So auto makers have been relatively free to replace copper with plastic.

*

Ralph Vartabedian cannot answer mail personally but responds in this column to automotive questions of general interest. Please do not telephone. Write to Your Wheels, Business Section, Los Angeles Times, 202 W. 1st St., Los Angeles, CA 90012. E-mail: ralph.vartabedian@latimes.com.

Advertisement