Do you need to do something special to maintain your diesel car?

Diesel engines have come a long way since the days when Rudolph Diesel used its first engine with peanut oil, and while the basic schematics of the internal engine design have remained true to their original roots, the technology has evolved throughout. over the decades to incorporate a lot of precision. external parts and sensors and it is fair to say that it is these additions that cause the most problems and require the most maintenance. Although a diesel engine block is as robust as it ever was and diesel engines are still capable of a service life of over 300,000 miles with a high level of maintenance, the addition of more delicate components such as precision fuel pumps, turbochargers. , high Pressure fuel rails and piezo injectors require good maintenance and service on a regular basis.

The diesel engine of the mid to late 90s was generally used in vehicles that were used on a regular basis, applications such as taxis and delivery vehicles that covered high mileage were ideal candidates for the longevity of the diesel engine and often these vehicles they would cover well over 400k or 500k miles on the same injectors and turbochargers. Over the past ten years, the diesel engine has increasingly found its way into family cars in general thanks to changes in technology that make the diesel engine much more refined, quieter, and often deliver similar performance. to its gasoline variants. Yet at the same time, diesel engines appear to be experiencing component failure and breakdown much more frequently and prematurely than their earlier cousins ​​used during the 1990s.

One reason for this could be oil and filter service changes. In the 1990s, diesel engines required 4000 to 6000 mile service, and it’s fair to say that in return, these same engines often returned close to half a million miles using largely the same engine components with which they were used. they left the factory. In comparison these days we frequently hear about turbocharger failures in some modern vehicles at just 40k – 80k miles, could oil service intervals play any role in these costly failures? I think it is possible, which is why I am writing this article.

Modern diesel engines have oil service intervals dictated in large part by an on-board computer, these are generally referred to as extended oil service intervals, and depending on driving style, they can range anywhere from 12k to 23k miles. Even using high-spec synthetic oil, I personally believe that these long service intervals (marketed to appease fleet managers of company-owned vehicles) are too far apart for an engine that uses a turbocharger. Oil is the lifeblood of any diesel engine, and that same crankcase oil is used to cool and lubricate the turbocharger bearings that drive a high-precision turbine that can rotate at up to 150,000 rpm. Of course, any small impurity or a drop in lubricating properties can cause wear and overheating of such a delicate part that it rotates at such a high speed. In examining many faulty turbochargers in relatively low mileage vehicles, I found severe bearing wear which led to a final failure that I can only attribute to the quality of the oil. I have also seen several turbochargers that have failed due to a lack of oil caused by blockages in the oil feed tube due to the accumulation of sludge, which again is a sign of infrequent oil changes and something that rarely happened in the turbo diesels of yesteryear that had more regular service intervals.

So my first advice is if you drive a turbo diesel car, ignore the service intervals displayed on the on-board computer and instead start your own service regimen by changing the engine oil and its filter. to no more than 6000 – At 7000 mile intervals, always use synthetic oil and make sure the replacement motor oil is of the grade specified for your vehicle and approved for use in your vehicle by the vehicle manufacturer. You don’t have to use the actual brand recommended by your vehicle manufacturer, just make sure the oil you purchase is approved for use in your engine by the vehicle manufacturer. I use a brand called Total Quartz, which is approved for use of my own personal vehicle and is very cost effective and suitable for most cars. Some people may think that changing the oil so frequently is an unnecessary expense, however compared to the cost of replacing a turbo and reducing engine wear, it is actually a common sense bargain.

It is also important to change the air filter and fuel filter every 20,000 kilometers, as the flow of air and fuel is very important for a diesel engine, and some modern diesels can even be interrupted if the fuel flow is reduced due to a Blocked fuel filter. Another weakness of modern diesel cars is the EGR valve, which is equipped to improve exhaust emissions, and because it handles engine gases, it can easily become blocked with carbon deposits that cause a malfunction. Cleaning the EGR is a bit tricky but can often be done by the auto mechanic and DIY brake cleaner or Mr Muscle oven cleaner is usually a good solvent for removing carbon deposits. The EGR should be checked and cleaned (if necessary) every 35k miles or immediately if you buy a second hand diesel car.

Some cars, like BMW diesels, also have a crankcase breather, which is a type of filter that can become blocked and cause a pressure build-up, which in turn can lead to wear and tear and turbo failure. be replaced at around 35k mile intervals. BMW has also recently improved the design of its crankcase breather, so owners of older vehicles should change their original crankcase breathers to the new version as soon as possible.

One of the biggest problems with newer diesel vehicles is once again attributed to the constant demand for improved emissions. Since 2008 it has been a legal requirement for European diesel car manufacturers to include a diesel particulate filter (often called DPF) in all diesel powered cars, this filter is mounted inside the exhaust system and is basically a grade version top of the catalytic converter. , but it is designed to trap soot particles produced during diesel combustion. Basically, a small amount of a special additive is automatically injected into the fuel tank at each fuel fill, this additive helps to trap soot particles in the DPF filter, thus reducing soot emissions from the vehicle, and in the Kingdom Kingdom generally results in a lower vehicle tax band.

Unfortunately, DPFs can eventually create many costly problems for their owners. DPFs are programmed by the vehicle’s computer system to ‘regenerate’ and basically burn off accumulated soot in predetermined periods as decided by the vehicle’s on-board computer. Regeneration is accomplished by heating the internal honeycomb of the DPF to red-hot temperatures that ignite and burn the leaked soot deposits, essentially cleaning itself. Unfortunately, this process can only be done during a fairly long drive, at high revs at highway speeds. If a car equipped with a DPF is rarely used on a highway, or if the DPF regeneration process occurs during a time when the car is only used for short trips, then it may fail to complete properly, which could result in for the DPF to become clogged or damaged, resulting in a warning light coming on, requiring the owner to drive the car on a highway for a distance just to trigger another regeneration attempt. If the DPF continues to be blocked then a DPF replacement is required at a cost of £ 1000 – £ 2000. The additive that is injected into the fuel tank is stored in a separate tank or in a bladder bag, which you will eventually also need be refilled by a dealer and an ECU reset, usually at 60k – 80k intervals.

Diesel owners who wish to avoid the potential expense of trouble with the DPF and its maintenance, would be better off choosing a diesel car made before 2008 and not having a DPF installed, and this advice would also be extended to those who only travel distances. short or not. use the highways regularly. Some automakers like Saab, BMW, Mercedes and Citroen chose to equip some models of their diesel vehicles with DPF before the 2008 deadline and others also included it as a factory option, so if you buy a second-hand diesel car hand, it’s worth double. check if a DPF has been installed, even if it was built before 2008.

So here is my personal service regimen for my own diesel car, and this is what I would recommend to any diesel car owner.

6000 to 7000 mile intervals – Oil and filter change. Use only synthetic oil approved by the manufacturer and of the grade specified for your local conditions.
12000 Mile Intervals – Air and Fuel Filter Change
35000 mile intervals – Check and clean EGR filter and replace crankcase breather filter (if installed)

None of the above are especially expensive during the normal course of ownership and are certainly more profitable than any problems or repairs that may arise due to poor levels of maintenance or neglect of the vehicle, so good maintenance pays off in the long run. . Often times, costs can be reduced by doing general service yourself, and genuine parts can often be found at auto stores and even on eBay.