How to Diagnose Diesel Engine Belt Noise

In our past blog, we discussed engine noise that occurs when your diesel engine is under load. This problem can be caused by bad gaskets or oil that is too thin. To learn more, check out our blog! We also have a video on the topic!


But that's not the only factor that can cause unwanted noise in your diesel engineyour belts can also factor in. 

The belts are located in the front of the engine. They drive various components, such as fan hubs, alternators, power steering pumps, and air conditioning pumps. There might be one belt or as many as six. Engine noise can be cause by just one belt, or it might be a combination, so you'll want to be sure to check them all.




The adjustment of the belts can create engine noise if it's off. So the first thing you'll want to do is check to make sure they're adjusted correctly. If they're too loose, they can actually slap, making a ticking sound. If they're good and tight, almost like a violin string, then it's not the tension of the belt making the noise. Instead, it might be the condition.



When you're checking the condition of your belts, there's a couple of factors that could contribute to engine noise. For example, you'll want to look for chunks that have come off the belts, or if they're dry or cracked. When they make their rotation around a pulley, the missing piece or crack in the belt can actually make an audible noise as it's rotating.

How to Check


When you make an adjustment, you want to restart the engine. For example, if the belts were loose, and you need to see if the noise is gone, or if it's still happening. If the noise is gone, then you've fixed the problem. If the noise is still there, that's when you want to check the condition and make sure there aren't any pieces missing or any cracks. If there are cracks or missing chunks, then you want to replace the belt or belts. Then restart it and see if the noise goes away. If it does, then you've resolved the source of the noise. 

If the noise is still there, then most likely the belt was not the problem. The next thing to check would be your valvetrain components.

Think you might be having a different engine problem? Take a look at these other common diesel engine problems.

Need some diesel engine parts to help stop your engine noise? We have certified techs on staff to help you find the right parts for your engine! Call us at 844-304-7688. Or request a quote online!

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