Car Radiator – Consequences Of Car Radiator Overheating

Car Radiator - Consequences Of Car Radiator Overheating
Car Radiator - Consequences Of Car Radiator Overheating

First of all, simple maintenance, can do wonders for the cooling ability of your car radiator.

Because, excessive contaminants on both the inside and outside of your car radiator; can cause a severe drop in cooling efficiency.

So, clean coolant in a sealed and pressurized car radiator can; efficiently transfer heat away from your engine.

Every engine out there today should be operating within a; normal temperature range. Most of the time this is going to be around 195 to 220 degrees F.

Engine Cooling System Illustration
Engine Cooling System Illustration

So, a relatively constant operating temperature is absolutely essential for; proper emissions control, good fuel economy and performance. A 50/50 mixture of water and antifreeze will boil at 225 degrees, if the radiator cap is open.

So, what do you need to increase the boiling point.

You need a clean sealed cooling system that holds pressure. Along with, a radiator cap rated at 15 psi. This will raise the boiling point of a 50/50 coolant mixture up to 265 degrees. If the mixture is raised to 70/30, the boiling point goes up to 276 degrees.

Why Excessive Heat Kills Newer Engines

The clearances in today’s engines are a lot smaller; than those in engines built in the 1970s and 1980s:

  • Piston to cylinder wall clearances are much tighter to reduce blow-by for lower emissions.
  • Valve stem to guide clearances are tighter to reduce oil consumption and emissions.
Aluminum Cylinder Heads
Aluminum Cylinder Heads

Many engines today have aluminum cylinder heads. But, aluminum does not handle higher than normal temperatures well; making it vulnerable to heat damage.

Consequences Of Engine Overheating

So, if the engine overheats; the first thing that will happen is the engine will start to detonate.

Also, the engine will ping and start to lose power under load. Usually, caused by the combination of heat and pressure exceeding the octane rating of the fuel.

If the detonation problem persists the hammer like blows may damage:

  • Pistons
  • Rings
  • Engine bearings
Damaged Piston Rings
Damaged Piston Rings

Overheating can also cause pre-ignition. Because, hot spots develop inside the combustion chamber; that become a source of ignition for the fuel. As a result, the erratic combustion can cause detonation; as well as engine run on in older vehicles. Also, hot spots can burn holes, right through the top of pistons.

Engine overheating can cause a blown head gasket. Heat makes aluminum swell almost three times faster than cast iron.

The resulting stress can distort and warp the head damaging areas like:

  • Like those between exhaust valves in adjoining cylinders.
  • Also areas that have restricted coolant flow; like the narrow area that separates the cylinders.

The typical aluminum head expands the most in the middle; crushing the head gasket. As a result, causing a loss of torque allowing coolant and combustion to leak.

Engine Damage From Car Radiator Overheating

Bent Valves From Car Radiator Failure
Bent Valves From Car Radiator Failure

So, if the coolant gets hot enough to boil; it may cause hoses or the car radiator to burst. Pistons may swell up and scuff or seize in their bores. Exhaust valve stems may stick or scuff in their guides. This, in turn, may cause valves to hang open. As a result, damaging pistons; valves and other valvetrain components. Finally, if coolant gets into the crankcase; engine bearings will fail.

Engine overheating can be caused by anything that; decreases the cooling system’s ability to absorb, transport and dissipate heat.

Common Causes Are:

  • Low coolant level
  • Loss of coolant (through internal or external leaks)
  • Poor heat conductivity inside the engine; because of accumulated deposits in the water jackets
  • A defective thermostat that doesn’t open
  • Poor airflow through the radiator
  • A slipping fan clutch
  • An inoperative electric cooling fan
  • A collapsed lower radiator hose
  • An eroded or loose water pump impeller
  • Even a defective radiator cap
Water Pump Failure
Water Pump Failure

So, heat always travels away from an area of higher temperature; to an area of lower temperature. So, the only way to cool hot metal; is to keep it in constant contact; with a cooler liquid. Consequently, as soon as the circulation stops; temperatures begin to rise. As a result, the engine starts to overheat. Now there is no way to remove the heat from the coolant.

Circulation Will Stop If:

  • The water pump fails
  • Your thermostat is not working
  • You have a loss of coolant replaced by air

The coolant needs a way to get rid of the heat it soaks up; while passing through the block and head.

So, the car radiator must be capable of doing its job; which requires the help of an efficient cooling fan. Finally, the thermostat must be doing its job; to keep the engine’s average temperature within the normal range. So, if the thermostat fails to open; it will effectively block the flow of coolant and the engine will overheat.


Clogged Car Radiator
Clogged Car Radiator

So, car owners don’t maintain their cooling systems as well as they should. As a result, the most common problems car radiators fall prey to is clogging and leaks. Dirt, bugs and debris can block the airflow through the core; and reduce the radiator’s ability to dissipate heat. Finally, internal corrosion and an accumulation of deposits; can likewise inhibit coolant circulation and reduce cooling.

Thank You !