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Causes of Diesel Engine Overheating

Having an engine overheat, be it diesel or gasoline, is not a good thing. It can lead to a lot of problems and costly repairs. Depending on the climate you operate and/or live in, the engine could be more or less susceptible to overheating. Desert and tropical regions will obviously increase the risk of an overheat because of the high temperatures and humidity. Colder regions in the north will have less opportunity because of the cold temperatures most of the year, but it does get warm there, so you won’t be totally out of the woods. Knowing the cause of diesel engine overheating will help you prevent it from happening.

Malfunctioning Water Pump

The water pump has an important job. It’s responsible for circulating the coolant throughout the engine to all the vital parts to prevent the diesel fuel from overheating. The water pump will start to wear down and fail when the seals start to go bad. That will happen if the pulley connected to the fan clutch assembly spins freely, without any resistance. When the seals fail, the coolant doesn’t get dispersed, and the truck engine starts to overheat.

Bad Fuel Injectors

Another cause of diesel engine overheating is bad fuel injectors. If the fuel injectors aren’t firing properly and sending fuel into the chambers, the engine will have to work harder. The lack of fuel means that all the pistons aren’t firing, and the ones that are work harder to make up for the others. That leads to overheating. Fuel injectors get clogged by buildups of deposits in the injector nozzle and is a common cause of diesel engines overheating. A quick inspection of the injectors will reveal if they are clogged, and then they can be easily cleaned.

Issues With the Coolant

Checking the engine coolant and making sure there are no issues with it is the easiest check to make. Look to see if it’s cloudy or if you have enough in the engine and reservoir. Cloudy coolant means that there is a leak somewhere, and other liquids, like oil, might be mixing in. If the reservoir is low, then there isn’t enough coolant in the engine. Top it off and keep an eye on the level. If it goes down fast, then this is a symptom of engine damage from overheating via leaks.

Bad Cooling Fan

The radiator fan brings cool air into the engine compartment. Any problems with it or the clutch assembly will lead to overheating. Make sure the fan is turning freely and is in the right position. Check the coolant sensor, thermostat, and the fan motor to make sure they are working. Failure of any of those parts will cause diesel engine overheating.

In the New Jersey area, come to HFI Truck Center for all Isuzu commercial truck parts. Our parts department has what you need to fix your truck. Contact us today to learn more!