The Most Common Diesel Engine Problems and Solutions

The Most Common Diesel Engine Problems and Solutions

Problems with diesel engines can be very daunting when you begin to experience diesel problems, especially when you’re unfamiliar with the machinery. Issues with diesel engine parts can occur through wear and tear, but sometimes these issues can be more complex. 

This handy guide explores the most common problems with diesel engines so that you can be prepared and aware in the unfortunate event that you experience difficulty with different diesel engine parts.

Issue-Specific and Part-Specific Problems with Diesel Engines

The most common diesel problems can be split into two categories which mostly overlap; issue-specific and part-specific. 

The four most frequently occurring issue-specific problems are:

1. Engine overheating

2. Oil leakages

3. Oil supply problems

4. Using the wrong fuel

Now, let’s discuss each of these problems in more detail.

1. Engine overheating

The number one problem found in diesel engines is engine overheating. Engine overheating is caused when an engine is pushed too hard and can give rise to a whole host of negative side-effects. This is including, but not limited to:

Damage to the bearings and crankshaft.

Pistons expanding and scraping against cylinder walls (crushing the head gasket in the process).

Cylinder heads swelling, distorting and breaking.

2. Oil leakages

Oil leaks stem largely from issues with diesel engine parts, such as aged seals and gaskets which no longer work effectively. If left unattended, oil leaks can cause serious diesel problems, as they pose both an environmental threat and serious fire risk and can result in complete engine failure.

3. Oil supply problems

Oil supply problems predominantly stem from either incorrect oil use or a lack of oil. Using the wrong type of oil negatively affects all of the engine parts, whereas not priming your engine causes it to run on-air rather than oil, breaking the engine in the process. 

4. Using the wrong fuel

Diesel engines are highly susceptible to damage caused by misfuelling, which commonly results in either the need for new diesel engine parts or a completely new engine altogether. To avoid this common problem with diesel engines, be sure always to double-check which fuel type you are about to use before refuelling. 

Diesel Engines Parts Known to Have Problems

The most frequently occurring diesel problems concern the following key engine parts, many of which (although not all) are in conjunction with the above issues:


Pistons are an important part of the engine and can fail in several ways. These include:

The timing belt snapping.

Piston rings becoming worn out.

Piston slap (a noisy piston).

The piston becoming burnt (usually by dirty fuel injectors).

The piston becoming cracked (caused by frequent use of poor quality fuel).


The most frequent cause of failure in gaskets is overheating via coolant leaks. However, in general, diesel engines are more prone to gasket failure than other engine types, largely because diesel gaskets regularly face higher combustion pressures. Repair of diesel gaskets is made all the more complicated (although not impossible) by the intricate nature of diesel engines.

Cylinder heads

Problems related to cylinder heads are usually categorised by loss of compression. Cracks in cylinder heads which lead to leakages are also a common issue, as are internal casting defects.


Bearings face a lot of stress due to the daily friction they experience- insufficient lubrication can therefore lead to bearing (and consequently engine) failure. Other causes of bearing damage include an improper selection of bearing material for the engine type at hand.

The most common problems with diesel engines will incorporate a mixture of the above issues and affected diesel engine parts. However, it must be emphasised that the above offers a simple overview only, and additional diesel problems certainly exist. Each issue is multi-faceted, with parts affected and displayed in numerous ways. 

Solutions to Common Diesel Engine Problems

All diesel engines are different, and as such when it comes to problems with diesel engines there’s no ‘one size fits all’ solution for any diesel engine problem, whether common or uncommon. It must also be noted that it’s imperative to determine the cause of the diesel problem and address this issue before simply replacing damaged parts and re-assembling the engine. 

If you’ve been experiencing problems with your diesel engines, please don’t hesitate to contact Foxwood Diesel with your engine number, and exactly what difficulty you’ve been having, or you may find our blog post on how to keep your diesel engine in good condition a useful resource. 

How Can Foxwood Diesel Assist With Diesel Engines Parts?

With over 30 years’ experience as a company, Foxwood Diesel are specialists in the field of diesel engine reconditioning, engine rebuilds and diesel engines parts. We hold large quantities of diesel engine spares, many of which are available for same-day dispatch, and which are tailored to a range of car manufacturers, including Mercedes, Volvo, DAF and all other major diesel manufacturers. With our expert knowledge of diesel systems, we offer highly effective reconditioning and rebuilding solutions at our engine machining centre for worn-out engines requiring professional care. Please don’t hesitate to contact us so that we can find the right solution for your diesel problems!