Common Diesel engine noise problems

There is a common problem in engines that might scare you – engine noises. However, not every strange noise that comes from under your car’s hood is bad – some sounds are normal. There are several types of bad noises produced by the engine – from rattling and knocking, to whining and other strange sounds. If you do not pay attention to them, they all could cause you lots of headaches. In the following lines, we will do our best to bring some clarity on the topic.

Why diesel engines are louder than petrol ones?

The petrol and diesel engines are both internal combustion engines, made to convert the fuel energy into mechanical energy. The main difference between the two is in the compression. In the diesel engines, the fuel is injected into the already compressed air inside the cylinder. These types of engines are much noisier than the petrol ones because their mechanics work under higher pressure. There are a lot of small parts inside, such as metal caps, small valves and oil pipes, that create the noise. Furthermore, the diesel fuel is less filtered than petrol and has more particles in it, that makes it louder when it’s ignited. ​Diesel engine problems ​usually happen because people have overlooked the bad noises which indicate problems.

Diesel engine noise problems

There are several types of bad noises that can indicate a problem with your diesel engine:

  1. Rattling noise. This type of noise could happen when you accelerate your vehicle. It’s caused by air and fuel mixture in the cylinder that gets ignited prematurely by the compression inside the engine. That is called pre-ignition and it can damage the pistons, valves, and connecting rods inside the engine.
  2. Diesel engine ticking noise. Usually, it is caused by reciprocating components like valves, pistons, rods and pushrods. The sound is an indicator of several issues such as low oil level, ill-adjusted valves, rod knock or noisy lifter.
  3. Diesel engine knocking. The knocking noise is produced by the injectors. Normally, the lubricant in the purge reduces the sound, but you should take a closer look at the engine if the noise did not disappear within fifteen minutes of working.
  4. Timing chain meshing noise. The timing chain connects the crankshaft and camshaft, so it’s important to maintain it at all times. The noise produced by a bad timing chain is a rattling one when the engine is cold, and a toned-down one when the engine is fully warmed up.​ These diesel engine problems​ are very common and it’s important to take care of them in a timely manner.

Diesel engine noise troubleshooting

As we have mentioned, the noises from your engine must not be overlooked. It’s important to diagnose the sounds as they appear. So what could you do if you hear one of the abovementioned noises?

First, you must ensure that you get the engine diagnosed. ​The Motor Company ​can help you with ​troubleshooting any noises from your diesel car, ​simply place your inquiry via our website or give us a call at 0116 287 0792.

  1. If you have a ​rattling noise​, you probably use the wrong type of fuel. This could be an easy fix or something more complicated like belt tensioner which applies ​force to create or maintain tension.
  2. The ​diesel engine ticking noise​ could be a sign of low oil level that causes the valvetrain components to not get proper lubrication. Check your oil level immediately and if it’s low, you must service your car. Another culprit causing this noise could be a faulty lifter or a bad connecting rod. The bad news is that you will need to rebuild the motor.
  3. Diesel engine knocking. ​This is not always a cause of concern. The reason your injectors are knocking is that they are not well lubricated. If you use good fuel, the injectors would stop knocking and clicking. There is an easy way to fix that problem by replacing the injectors with new ones.
  4. Timing chain problems. ​The noise coming from the timing chain is usually caused by its looseness. If you postpone fixing it for too long, it will tear off. That could damage your engine seriously and it will cost lots of money. That’s why you must fix the problem quickly.