First-Time Diesel Owners Beware: Extra Maintenance Is Required

If you're new to owning a diesel, there are a lot of maintenance items you should be aware of. Diesel engines, while extremely powerful, are also somewhat fragile if not maintained properly. In fact, failing to complete any one of these basic maintenance tasks could result in your diesel breaking down. But if you properly care for your diesel, you'll have an engine that generates tons of torque, accelerates any big load, and offers you the kind of fuel efficiency that you would expect from a much smaller motor. Diesel's many benefits even have some people predicting that one day in the future all people will own diesel engine vehicles instead of gasoline -- so these maintenance tips might be very important to you down the road.

Nearly all new diesel engines come equipped with a turbo-charger. The turbo-charger is a lot like a jet engine - there are compressor blades inside the turbocharger that can spin at 20k or 30k rpm. As these blades spin, they force clean outside air into the engine, increasing engine efficiency and performance. But because the turbo-charger is so powerful, great care must be taken to make sure the air entering the turbo-charger is clean and clear of debris. If a small piece of debris were to enter the turbo as it was spinning at max speed, it's possible that one or more compressor blades would shatter (ruining the turbo). Therefore, it's incredibly important that the air filter on your diesel is clean and properly installed. Most manufacturers equip their vehicles with electronic sensors that will tell you to check or replace your air filter, but you can manually check the air-filter using the restriction gauge. The restriction gauge, found on near the filter, will tell you if your air filter has become too clogged to protect your turbo-charger. If the gauge indicates your filter is too clogged, you should replace it immediately. Unlike a gasoline engine, failure to change your diesel's air filter will lead to thousands of dollars in engine damage relatively quickly -- even in just a few hundred miles. In fact, it's a good idea to keep a spare air filter on hand at all times.

Even if you don't have a turbo, there are lots of other maintenance items that are especially important on diesel engines. Fuel filters are critical to proper diesel performance because diesel fuel, unlike gasoline, contains quite a few impurities. While a gasoline engine fuel filter might require replacement once every 30k miles (mostly as a precaution), diesel fuel filters can become clogged in as little as 10k miles. Make sure to check your owner's manual to find out what your manufacturer suggests. If at all possible, use the same service station every time you refuel. That way your chances of buying a bad tank of diesel are reduced.

Diesel fuel, in addition to having a lot of impurities, also contains water! Even though small amounts of water will not hurt your diesel engine, water does reduce economy and performance. Therefore, most modern diesels are equipped with fuel-water separators. Depending upon your vehicle manufacturer, you may need to manually purge the water from your diesel's fuel system as often as once a month. Make sure to check your owner's manual for instructions. In some cases, if you don't purge the water from your diesel's fuel system you will experience poor performance and fuel economy. Luckily, many service facilities will perform this task for you at little or no charge. They'll also dispose of the contaminated fuel/water mixture.

A lot of old-timers call Diesel engines "oil burners" because, unlike gas engines, diesels burn some of the engine's lubricating oil during normal operation. In fact, diesel engines under heavy use can burn two or three quarts of oil between changes. That's why it's especially important to check your diesel's oil level regularly. When you check the oil make sure the engine has cooled for at least 30 mins and that your vehicle is on level surface. The owner's manual will explain when you should add oil based on the oil dipstick reading. Remember to do this often -- if the oil level falls too low you will suffer engine damage.

Diesel engines don't like cold temperatures. At temperatures below zero, diesel fuel may "gel" (turn from a liquid to a semi-solid). Below freezing, diesel engines tend to start harshly and warm-up very slowly. At extremely low temperatures (below -10 F) normal diesel engine oil does not protect the engine from friction. Therefore, it's very important to remember to use your diesel's block heater if outside temps ever dip below zero. If you can afford the electricity, I recommend you plug-in your block heater any time the outside temperature dips below freezing. This will protect your engine, keep your fuel warm and gel free, make for quick and smooth start-ups, and it will help your engine warm-up quickly. Check your owners manual, but usually your block heater plug-in is wire-tied to a harness behind and underneath the bumper.

Unlike most modern gasoline engines, new diesel engines often have a manufacturer specified break-in period. During this period (usually the first 500 or 1000 miles) your owner's manual will tell you to avoid driving at sustained speeds and to refrain from towing or hauling. In other words, it's best to avoid any long highway trips or any heavy use for the first few days or weeks. Once this initial break-in period is over, it's not uncommon for your diesel to continue to break-in for the first 20,000 or 30,000 miles. Unlike gasoline engines, which are truly broken-in after 3k to 5k miles, diesels need lots of time and use to reach their peak efficiency and performance. Most long-time diesel owners will tell you that their diesel didn't really start to perform until the engine had a year or two of use.

In summary, any new or first-time diesel owner should read their diesel's engine manual. They should also make sure to keep a close eye on the air filter restriction gauge, change the fuel filter often, always check engine oil between services, purge water from the diesel fuel system, and use the block heater anytime outside temperatures drop below zero degrees Fahrenheit. By taking the time and effort to do these extra tasks, your diesel engine should reward you with 200,000+ miles of service.