The Most Common Diesel Engine Problems and Solutions

Knowing what to do when you begin to experience problems with your diesel engine can be incredibly daunting, especially if you’re unfamiliar with the machinery. The following is your handy guide to the most common problems diesel engines face, so that you can be aware and prepared in the unfortunate event that your diesel engine starts to experience difficulty- straight from the experts at Foxwood Diesel.

Issue-Specific Problems and Part-Specific Problems


The most common diesel engine problems can be split into two categories; issue-specific, and part-specific, most of which overlap. The most frequently occurring issue-specific problems are as follows;

  • Engine overheating; the absolute number one problem diesel engines face, engine overheating is commonly caused when an engine is pushed too hard, and can give rise to a whole host of negative side-effects, 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), and cylinder heads swelling, distorting and breaking.
  • Oil leakages; oil leaks stem largely from aged seals and gaskets which no longer work effectively. Left unattended, oil leaks pose both an environmental threat and serious fire risk, and can result in complete engine failure.
  • Oil supply problems, predominantly either incorrect oil use or a lack of oil; the wrong oil negatively affects all of the engine, whereas not priming your engine causes it to run on air rather than oil, breaking the engine in the process.
  • Using the wrong fuel; diesel engines are highly susceptible to damage caused by misfuelling, which commonly results in either the need for new engine parts or a completely new engine altogether.

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

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  • Pistons; pistons are an important part of the engine and can fail in a number of 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), and the piston becoming cracked (caused by frequent use of poor quality fuel).
  • Gaskets; the most frequent cause of failure in gaskets is overheating (see above) 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; 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 improper selection of bearing material for the engine type at hand.

Most common diesel engine problems will incorporate a mixture of the above issues and affected parts. However, it must be emphasised that the above offers a simple overview only, and additional problems certainly exist. Each issue is multi-faceted, with parts affected and displayed in numerous ways. Keep reading our blog for further information on causes, symptoms and solutions of all problems diesel engines regularly face.

Solutions to Common Diesel Engine Problems


All diesel engines are different, and as such, no ‘one size fits all’ solution exists for any one diesel engine problem, whether common or uncommon. It must also be noted that it is imperative to determine the cause of the problem and address this, before simply replacing damaged parts and re-assembling the engine. Contact Foxwood Diesel today with your engine number, and exactly what difficulty you’ve been having.

Foxwood Diesel are specialists in the field of diesel engine reconditioning and engine rebuilds, with over 30 years’ experience as a company. 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 to worn out engines requiring professional care. Get in touch so that we can find the right solution for you!