Original Equipment Manufactured versus Generic Parts: An Auto Parts Blog

Hi, my name is Stan, and I want to welcome you to my blog. I love working on cars, and I have worked on them since I was a little kid working alongside my dad. Over the years, I have seen vehicles grow more complicated, and I have also seen a range of parts manufacturers enter the market. Some of them make amazing parts while others make parts that aren't quite as good as original manufacturer parts. If you want to learn about the differences between generic and original parts or if you have other questions on auto parts, this blog has the answers you need. Please get comfortable and start exploring.

Glaze Runner: What Is Cylinder Glazing, And How Can I Prevent It Happening To My Diesel Engine?


The average diesel engine is an enormously reliable and robust piece of equipment, and is generally significantly less vulnerable to serious mechanical failures than an equivalent, petrol-driven engine. However, these redoubtable engines are vulnerable to some mechanical problems that are specific to diesel engines, and one of the most common and difficult to deal with is the phenomenon known as cylinder glazing.

What is cylinder glazing, and how does it occur to diesel engines?

One of the reasons diesel engines are so reliable is simply because they are less complex than petrol engines, with less components that can potentially go wrong. For example, while spark plugs are used in a petrol engine to ignite the fuel in the engine's cylinders and provide drive, diesel engines do not have spark plugs, and instead rely compressing the diesel fuel in the cylinders until it ignites spontaneously.

While this simplified ignition process may make for a simpler, more reliable engine, it does mean that a diesel engine should not be left idling for significant periods of time, especially if the engine is relatively fresh from the factory floor. Running a diesel engine at low loads for long periods causes the pressure inside the cylinders to drop, impeding proper combustion and leaving filmy deposits of unburnt fuel behind in the cylinder.

This syrup-like film accumulates around the piston rings of an affected cylinder, causing them to become clogged and preventing them from sealing hot gases within the cylinder. This causes a further loss in engine power, but to make matters worse, the rush of hot gases escaping the cylinder 'bakes' the unburnt fuel residue onto the interior surfaces of the affected cylinder. Once this occurs, the cylinder becomes too smooth to effectively draw in oil as it moves back and forth, leading to rapid overheating and, potentially, catastrophic engine damage.

How can I prevent cylinder glazing, and repair it if it does occur to my engine?

As you can imagine, cylinder glazing is something you want to avoid at all costs; fortunately, that usually isn't too difficult. Since diesel engines are not designed to function at a small fraction of their maximum load for extended periods, the best way to prevent glazing occurring is to avoid idling (or driving at particularly low revs) for extended periods, especially during the first few months of an engine's working life. Once a diesel engine has been 'worn in', it generally becomes much less vulnerable to cylinder glazing, although it can still occur in rare circumstances.

If your cylinders do become glazed, the first symptoms you will notice are a loss of engine power combined with a rapid increase in engine temperature, two symptoms that will force you to take your vehicle off the road whatever their cause. If this occurs to your engine, have it taken to a engine repair services that specialises in diesel engines, as they will have the equipment and knowledge to quickly and conclusively determine whether cylinder glazing is causing your problems.

If your cylinders have become glazed, they can be replaced, but they may not be beyond repair if the problem was spotted quickly. Diesel repair services can use special abrasive powders to scrape the glazed, hardened fuel residue from the surfaces, bores and piston rings of your affected cylinders, bringing them back to normal service for a reasonable price and within a reasonable amount of time.


2 February 2018