Overheating is detrimental to your engine, or any component in your vehicle really. Serving to cool the engine and prevent it from overheating, the radiator thus plays a vital role in your engine performance. That said, a clogged radiator that cannot function properly can lead to severe damages.

Thus, knowing the common symptoms of a clogged radiator and how to fix each problem at hand is a basic and vital maintenance skill that you must master to ensure optimal engine performance as well as saving yourself expensive and complicated repairs.

#1 – High Temperature Gauge Readings

Since a functional radiator prevents the engine from overheating, you will know something is wrong with the radiator if the engine starts overheating.

Monitor the temperature gauge to see if the readings are higher than usual or if the needle is in the “red” zone. Some newer cars will display the temperature digitally and warn you when the engine temperature gets too high.

#2 – Coolant Leaks

The housing or cooling fins may develop tiny holes or cracks on them when the radiator is clogged due to severe rust buildup. Once this happens, you may be able to see small drops of coolant on your garage floor or driveway.

The rust inside your radiator often forms due to a low quality coolant or adding regular tap water (instead of distilled) to the coolant mix which has many more contaminants. If a radiator flush is not regularly done, more and more rust will form and start eating away at the radiator tank.

#3 – Fluid Discoloration

Vehicle coolant should be a bright color, often green, yellow, or orange (but sometimes red, pink, or blue) and flow freely through the radiator and coolant passages within the engine.

Over time, internal deposits and even sludge can contaminate the coolant. This will turn it into more of a rusty color or even the color of oil. Checking the coolant overflow tank is often the easiest way of checking the condition of the coolant.

#4 – Exterior Radiator Fins Blocked

Radiators are designed for maximum cooling. To accomplish that, thin fin tubes run across the front of the radiator. These tubes carry hot coolant. As you drive, the radiator fan pushes outside air on and around these fins to lower the temperature of the coolant before it flows back into the engine.

If these tubes become clogged up by dirt, bugs, leaves, or other material, the airflow is blocked which doesn’t allow the coolant to cool as much as it needs to.

#5 – Bent or Damaged Fins on the Radiator

In addition to clogging due to foreign material stuck to the front of the radiator, airflow can also be blocked when enough fins get bent or damaged. These fins are extremely delicate and a piece of tiny gravel hitting them while driving can cause damage. 

Damage can also occur during installation of a new radiator or even when spraying water to clean off the fins.

#6 – Heater for Passenger Area Not Working

The cabin heater of a car depends on hot coolant passing through the heater core and then the resulting hot air being blown into the passenger area by a blower fan. If the radiator is clogged or has a leak, not enough hot coolant makes its way to the heater core to allow proper warming of the car’s interior.

#7 – Sludge in the radiator

The coolant in your vehicle should be yellow or green or red normally. As the radiator goes bad, contaminants discolor the fluid making it a rusty or oil color. This turns into sludge and the fluid will not be able to cool the engine efficiently because it will not drain properly and remain in the radiator. This can be from a failing radiator for vehicles that contain a transmission cooler inside the radiator. The barrier between the coolant and transmission fluid fails and the fluids mix. If you or a mechanic notice sludge in your radiator, it will need to be replaced as it can cause extensive damage to the engine and transmission.

If you have more question about your radiator, give us a call at Bob Workmans European. We can answer all your questions!