This topic is actually the famous issue that everyone behind the wheel knows but keeps postponing by saying “the weather hasn’t fully warmed up yet, there’s still time.” During the freezing cold of winter, we relied on the protection of antifreeze, traveled the roads with the warmth of the heater, and chased our livelihood through snow and ice. But when winter ends, the real test for a truck’s cooling system is just beginning. The salt spread on the roads throughout winter, that sticky mud, and all the dirt carried by humid air cover the radiator fins almost like armor. When spring arrives and the sun shows its face, that armor turns into a choke point that prevents the engine from breathing.

At Mesay Otomotiv, every spring we host dozens of friends who say, “Master, the truck ran like a clock in winter, but now the temperature rises on climbs and the fan never stops.” Let’s talk about that critical cleaning you need to do after winter to avoid this problem — explained in the “workshop language,” with real experiences, and in a completely human-touch guide.

Why Does a Truck Radiator Get Clogged?

Let’s be honest; when washing the truck in winter, most of us say “just wash it, that’s enough.” But that salty water mixture splashing onto the radiator when you drive behind snowplows — that’s the real enemy. This mixture penetrates deep into the radiator fins and, when it dries, forms a layer as hard as concrete. The most searched question on Google, “Why does a truck overheat?” is often answered not inside the engine but in this “blocked nose” right in front of it.

It’s not just the outside either; deposits that accumulate in the coolant running at low temperatures throughout winter — sometimes without the thermostat fully opening — narrow the radiator’s internal channels, which are as thin as capillaries. If your radiator cannot operate at full capacity, the fan will engage more frequently. What does that mean? It means shortening the life of the fan motor, straining the belts, and most importantly, watching the fuel gauge drop a little faster. If you don’t want the temperature gauge to hit the red while climbing a hill with 30 tons in the deceptive spring weather that alternates between warm and cold, that radiator must shake off its winter fatigue.

How Is Radiator Fin Cleaning Done? Why Shouldn’t You Trust High-Pressure Water?

There’s a scene we see in workshops that makes our hearts ache: someone holding a high-pressure washer 10 centimeters away from the radiator. Don’t do it. The aluminum or copper fins of that radiator are extremely delicate. High-pressure water at the wrong angle can bend them like paper. Once the fins collapse (in workshops we call this “flattened fins”), it becomes impossible for air to pass through them. You would have effectively blocked the radiator with your own hands.

The correct method requires patience. First, spray radiator exterior cleaning chemicals (or a quality degreaser) onto the layer left from winter. Let the mud and salt soften thoroughly. Then wash it with low-pressure, wide-angle water — gently but consistently, like watering a flower. Do not say “it’s clean” until you see water pass easily through the fins and the water flowing out becomes clear. Especially in vehicles like Volvo and Scania that use high-engineering radiators, keeping those pores open is the only barrier between you and overheating.

Is Antifreeze Replacement Necessary? “Can We Just Add Water?”

There is a widespread myth in the market: “Antifreeze is only for preventing freezing in winter; it’s unnecessary in summer.” Anyone who says this — whether a mechanic or a friend — is actually shortening the engine’s life. Antifreeze doesn’t just prevent freezing; it raises the boiling point of water above 100°C and, most importantly, prevents rust, corrosion, and limescale formation inside the system. Antifreeze that has circulated inside the engine all winter and turned rusty in color cannot protect the engine in the warmth of spring.

The best approach when leaving winter behind is to completely drain the fluid in the system. Before draining, you can add a quality radiator internal cleaner and run the vehicle for a while so the scale and sludge inside the channels dissolve. Then drain it and refill the system with a mixture of new antifreeze and pure water at the manufacturer’s recommended ratio (usually 50–50). Why pure water? Because tap water contains lime, and lime is the killer of radiators and water pumps. At Mesay Otomotiv we always say: “You can’t save money with limescale water — you can only postpone the expense.”

Radiator Cap and Thermostat: Don’t Say “What Can Such a Small Part Do?”

When overheating problems are mentioned, everyone thinks of the big radiator, but sometimes the culprit is a cap barely worth the coins in your pocket. The radiator cap is not just a lid — it is a pressure valve. If the spring inside the cap has lost its strength, it cannot maintain system pressure. If the pressure remains low, water starts boiling at 100°C. But with a healthy cap, this can rise to 110–120°C. During spring maintenance, check the gasket on that cap; if it has hardened or cracked, replace it without hesitation.

Then there is the thermostat. A thermostat that has spent the winter staying “closed” or “half open” may say “I’m tired” and fail to fully open when spring arrives and the engine needs proper cooling. If your engine heats up faster than normal even at idle, or if the temperature gauge fluctuates up and down, your thermostat has probably submitted its retirement request. At Mesay Otomotiv, we recommend replacing these small components before they fail, especially in vehicles operating under heavy loads and dusty conditions. Because the cost of being stuck on a hill with 30 tons is a hundred times the price of a thermostat.

Tips to Avoid Overheating Problems:

Replacing parts alone is not enough; the driver must also keep an ear on the engine and an eye on the gauges. Here’s what you should check before hitting the road:

1. Intercooler Cleaning: Most people focus on the radiator, but the intercooler (air cooler) sits right in front of it. If it gets clogged, the air entering the engine becomes hot. Hot air means less power and more heat. When washing the radiator, make sure to clean it as well.

2. V-Belt and Tension Pulleys: Those belts that hardened in winter frost may loosen or slip in spring heat. If the belt slips, the water pump cannot circulate coolant fast enough. The result? Of course — overheating.

3. Fan Switch and Fan Clutch: Does your fan engage at the right time? Is the fan clutch (visco) doing its job? If you don’t hear that familiar fan sound when the vehicle heats up, visit a service center while you still can.

Mesay Otomotiv’s Note: Breaking Down in Summer Heat Is Not Fate!

Spring months are a kind of “renewal” period for heavy vehicles. Entering summer with a cooling system still carrying winter’s salt, dirt, and burden may force you to take an unwanted break on the road. At Mesay Otomotiv, when we keep radiator and cooling system products from world-leading manufacturers on our shelves, we aim for only one thing: your uninterrupted journey.

If you suspect your vehicle’s cooling performance or are wondering “Has my radiator reached the end of its life?”, instead of wasting time with temporary fixes you can explore the original or guaranteed equivalent parts suitable for your vehicle in our category. Remember, the cooler a truck’s engine runs, the more comfortable the driver feels.

A small intervention done on time is always cheaper than the heavy cost of breaking down on the road. Enjoy the spring, climb hills without the fear of overheating. May your road be clear, your engine cool, and your earnings abundant!