A smooth-running diesel engine is one of the most reliable and high-performing mechanisms out there. You rely on your engine for high performance, and that is what you get. One issue with a finely tuned machine, though, is that it can have real problems when part of it is out of sync.

That is what has happened when your diesel truck is running hot. When one component has issues, it can lead to problems throughout the system, which can cause serious damage if not rectified. These tips will help you sort out the causes of your overheating diesel engine so you can find and address the problem before it gets out of hand.

When Diesel Fuel Is Hot, What Does It Do?

Just as many things can cause your diesel engine to overheat, many things can go wrong if your diesel engine is overheating. When diesel fuel is hot, what does it do?

  • The main issue when your truck is running hot is that overheated diesel fuel leads to an increase in the formation of particulates in the fuel.
  • The thinner liquid components of your fuel will start to boil off, leading to thicker fuel and a higher proportion of solid debris in the fuel.
  • These particulates can clog key components of the fuel system, including the fuel filter and the injectors.
  • This can lead to serious damage to your engine if the problem persists and the engine is continually run at excessive temperatures.

Temperature and pressure control are key to keeping your engine and diesel fuel injection system functioning properly. If you’re already using a diesel fuel injection system, then you likely know that injection pressures of 30,000 psi create a fine mist of fuel and more efficient burning. However, this system can be compromised when the temperature rises too high. And when your diesel truck is overheating, the root cause may not be immediately obvious.

But with the right information, a sharp eye, and a visit to the mechanic, you can diagnose your engine issue and get back on the road. The following are just some of the common causes of an overheated engine.

Coolant Leaks

One of the most common causes of an overheating engine is coolant leakage. Coolant loss usually means that there are cracks or general damage in your vehicle’s gasket. If you notice a low coolant level or an excess of bubbles in the fluid, this is a sign that something is wrong. Get your truck to a professional to address the issue.

Broken Cooling Fan

Like a coolant leak, issues with the cooling fan can lead to overheating due to the failure to keep the system regulated. Simply put, when your cooling fan breaks, the engine will heat up too much.

  • This issue may warrant a replacement of the entire fan, but a repair may also do the trick.
  • Cooling fans sometimes break due to an electrical issue, so some wire fixes may also solve the problem.
  • This is where a professional can help. The proper diagnostic tools can help you zero in on the real culprit and save you time spent in trial and error repairs.

Clogged Diesel Injectors

Clogged injectors can result from an overheating engine, and it can also be the cause. When your fuel overheats and experiences higher proportions of solid debris, your injectors and other parts of the fuel system can get clogged. On the other hand, clogged injectors themselves can lead to an overheating engine.

  • If your injection system is having trouble releasing fuel, the engine may have to work too hard to compensate. This can cause it to overheat.
  • Make sure that you are checking your injections for clogs or leaks to keep everything running smoothly.
  • Also, make sure you have the necessary tools to solve the problem. For instance, if you’re working with Duramax injectors, have a Duramax injector rebuild kit on hand just in case.

Thermostat Faults

Sometimes your engine will be working just fine, but the sensors will be off and will prevent the engine from self-regulating important things, like the engine’s temperature. Your engine’s sensors may be faulty, making it difficult to regulate the entire system. So, if the thermostat cannot even tell that the engine is running too hot, it won’t be able to trigger cooling systems. A relatively minor issue like a faulty thermostat can lead to major issues that result from an overheating engine.

Collapsed Radiator Hose

Like the thermostat, a relatively small component of your engine can cause serious issues with the entire engine. Something as simple as a hose can clog up the cooling system and lead to major problems. Broken or collapsed hoses cause overheating since fluid cannot get to or from the engine without leaking. A mechanic will be able to easily spot this problem and can install a new hose for you. This minor repair, if handled in time, can save you on major repairs later.

Air Inlet and Exhaust System

If the air leaving your engine becomes restricted, your engine can become overheated. To see if this is the case, an inspection of the exhaust system is necessary.

  • First, conduct a visual inspection of the exhaust for any blockages.
  • If the exhaust seems clear, an internal inspection of the muffler will be necessary.
  • Check the airflow exhaust pressure. If it is lower than recommended, the issue could reside higher up in the exhaust system. There could also be an issue with hot air reentering the system and adding to the engine temperature.

Common Engine Problems Due to Overheating

When diesel fuel is hot, what does it do? Simply put, it can do damage to various parts of your engine. Your engine’s components are made to operate under specific circumstances. If conditions exceed what the system is designed to withstand, those components will start to break down. 

For example, when the system overheats:

  • The pistons can swell and cause scrapes and damage to the cylinders. Other components can suffer a similar fate.
  • The crankshaft can swell and break.
  • The radiator can crack.
  • Additional components like hoses, clamps, and seals can break and lead to further overheating and damage.

When your truck is running hot, a little knowledge and observation can help you detect the cause of your overheating engine. By having the right tools on hand, such as a Duramax injector rebuild kit, you can solve small engine and fuel injection issues at home.

Otherwise, you should always consult a mechanic before performing larger repairs. If you do, major issues like overheating can be easily solved. Either way, make sure you get the best parts for your diesel fuel injection system by getting them from Dieselogic.