Car Radiator Myth Busters: The Facts About Vehicle Cooling Systems

Ever since car manufactures started using radiators with plastic tanks the myths about radiators began flying. This article dispels some of the more popular myths floating around the Internet by providing the facts.

Myth 1: Slow Down or Slow Your Engine when Overheating

This is bad advice. Engine cooling is a combination for coolant flow and air flow across the radiator. Sometimes the best thing you can do is increase vehicle speed or engine speed to provide more coolant flow, more air flow or both.

I recall on one coast-to-coast trip driving through Arizona in 120+ degree temperature. My Porsche 944 Turbo was having a difficult time keeping cool at 65 MPH so I increased speed to 80 and it came down to normal operating temperature.

Another trick you can use if your vehicle is overheating is to turn on your heater. This works because the heater is basically a cooling coil that dumps heat from the engine inside the cabin of the vehicle. If it’s hot outside you’ll be uncomfortable, but you’ll save the engine.

Myth 2: Insects Will Ruin Your Radiator

While this could be true, the circumstance would have to be very extreme. We’re talking driving through a swarm of locust at a high rate of speed kind of extreme. Not likely.

Here are the facts. In areas where insect population is heavy your car, truck or SUV radiator will collect insect remains. The hot cooling coils will quickly dehydrate the bug remains until the only thing that remains are the wings and exoskeleton. A good, stiff stream of water will easily wash away the remains.

As long as you keep the car clean, you have nothing to worry about when it comes to bugs.

Myth 3: A Small Coolant Drip is Not a Big Deal

A little bit of glycol on the garage floor may not seem like a big deal, but it is. First of all it is against both state and federal laws to dump glycol and other hazardous substances into surface waters. When you park your car on the street that’s exactly what you will be doing. Rain water washes the coolant into the storm drain, which then dumps into surface waters.

Glycol is very poisonous. It has a sweet taste that dogs and small children find irresistible. So letting it out of your car — one way or another — is a recipe for disaster.

In addition to the health and environmental hazards, sooner or later a car radiator leak will end up being a cooling system failure. If the leak is on the radiator itself, it will eventually spit wide open and dump all of the coolant. If it is a hose, the hose will blow out and fail. If it’s a seal you will introduce air into the system that can cause a vapor lock preventing proper cooling. In other words, all kinds of nasty things can happen that will cost you a lot more time and money than fixing the problem when it is small.

Myth 4: All Anti-Freeze Products are Pretty Much the Same

I wish this myth was true, but it’s not. In fact, some car manufacturers, like Porsche, will void the car warranty if you don’t use the specified fluid. Be sure to check your vehicle owner’s guide before you pour any old product into the cooling system. Like your oil, this is a vital fluid and it needs to be the correct specification.

Myth 5: An All Aluminum Radiator is Best

I suppose if you are building a very high performance vehicle or a race car this would be true. Aluminum is very light and reducing weight is important when you’re goal is going fast. That said, aluminum is not the best heat conductor. Copper, for example, is much better.

The fact is that automobile manufacturers take a lot of factors into consideration, including weight, size, heat dissipation qualities, cost and durability. If you are replacing a defective unit then your best bet will always be original equipment (OE) or OE specification. If you are building a high performance vehicle, custom radiators should be considered.