Maintenance Tip of the Week: Cruising Speed 11/23/2015

Maintenance Tip of the Week – Cruising Speed 11/23/2015

Your Marinediesel engine was rated to be operated at WOT (Wide Open Throttle) a certain percentage of the time. Indeed, your warranty lists the limitations of WOT operation. Exceeding these limitations and ignoring the recommended cruising speed of your engine drastically reduces the life of the engine. If you will need higher performance than our standard warranty allows, you need to advise your local Marinediesel distributor at the time of order so that the engines may be appropriately rated.

Genuine Spare Parts – A difference worth choosing

You will often hear us telling our customer to only use Marinediesel genuine spare parts when performing maintenance on their engines. Though this may seem like merely a way to earn additional profit, there are some very good reasons to only use spares provided by either Marinediesel or our official distributors:

  1. Marinediesel engines are designed, tested, and certified with parts that are tested by us specifically for your engine model. We have no control over the production standards, quality, or compatability of aftermarket parts. Though the part may work to immediately fix a problem, it may not be 100% be compatible with your engine.
  2. On marine engines, all genuine spare parts are marine grade spares. Aftermarket parts may not be suitable to the marine environment.
  3. Only Marinediesel Genuine Spare Parts carry a one year warranty from Marinediesel.
  4. The use of improper spare parts or replacement parts will impact your warranty. Marinediesel’s warranty is issued with the expectation that parts either manufactured by us or provided by us will be covered under the warranty. In other words, using an improper part may void your warranty.

This article is not intended in any way as a comment on the quality of aftermarket spare parts. Indeed, in most cases aftermarket parts will be adequate. However, in order to ensure a long, proper service life of your engine, and compliance with your performance standards, only Marinediesel Genuine Spare Parts should be used for your maintenance and repairs.

Always check your serial number


Engines occasionally have mechanical problems. They all do. Often, when customers or distributors contact MarineDiesel for service or spare parts, the first thing we will ask, even before the problem, is for the engine’s serial number.

The serial number of the engine is always located on a metal tag on middle of the starboard  side of the engine (right side on non-marine or industrial engines). The serial number will be in the following format MD-XXX######, with six digits after the “XXX”.

Why do we ask for the serial number? Several reasons:

  1. Often, there have been service advisories, component upgrades, or changes to the design of the engine that were made after it was built. The serial number is logged at the time the engine is manufactured, and we instantly know what, if any, changes were made since that time.
  2. Warranty issues always require a serial number. If we have warranty repairs, we need to track them based on the date of manufacture.
  3. We need to verify the specific engine model. Though perhaps 80% of the components are compatible between engine models, around 20% are non-compatible.
  4. We need to check the version of the ECU software and whether any customizations were made.





Do we ever sell used engines?



Once in a very great while, someone will contact us asking if we can help them sell their used MarineDiesel engine.

Our answer in these cases is nearly always “No”.

There are several reasons why:

1. We are an engine manufacturer and our factory is set up for manufacturing, rather than keeping large inventories of used parts. We are not a retail shop, and have no showroom, so to speak. Though some of our dealers or distributors will deal in used engines, after shipping a used engine to those regions, it is rarely worth the cost.

2. We cannot sell used parts as new, so we cannot “part out” the engine.

3. Likewise, after an engine is commissioned, even with only 10 hours of use, we cannot sell that engine as new.

4. Engines returned for warranty reasons are nearly always used as training engines for training dealers or customers. We never can resell them.

5. From a pure financial perspective, engines typically depreciate as much as 50% at the time they are commissioned. Very seldom is the return worth the hassle from the owner’s perspective.

We are usually asked this question, 90% of the time, when an engine was purchased as part of a prototype vessel, and the contract was not awarded to the builder. Though we can occasionally make some arrangements in such instances prior to a new build on large projects in order to help mitigate the financial risk to the shipyard, we simply lack the facilities or personnel to assist much after the fact.





Maintenance Tip of the Week – Warranty 10/06/2014


Maintenance Tip of the Week:

In cases where you believe you may have a warranty issue:

You may or may not have legal remedies, but to ensure you have a proper record of the situation:

  1. Keep detailed records of engine maintenance that was performed, especially what was done and when.
  2. Make certain that what you are asking for is within the terms of your warranty. Many times, a claim is made when the engine was used improperly or the maintenance performed improperly or irregularly.
  3. Contact the engine dealer for assistance. They want to keep you as a customer.
  4. Through your dealer, contact the manufacturer. For instance, at MarineDiesel we will often honor a claim, even if it was not due to wrongdoing on our part or a manufacturing error. This is especially true if there are multiple problems that arose and a paper trail of maintenance performed was kept up to date.
  5. Be honest in your reporting. Technicians can usually tell if you are being truthful. For instance, we once had a claim that arose because of damage that arose from the customer operating without fuel filters. This was easily diagnosed when brand new filters were in place on the engine when the technician arrived and a vessel moored next to it had no filters. Once you are caught, future claims come into question.
  6. Pay attention to service updates from the manufacturer. Very often mechanical issues become known after time in service and easy, preventative fixes are quickly made, reducing the likelihood of a claim.
  7. READ THE MANUAL! The service intervals and procedures in the manual were developed by a long research and development process. They really are what needs to be done to ensure a long service life and adequate performance. Manuals are updated as more information becomes known. Seemingly simple maintenance operations are included in the manual for a reason.

Every engine manufacturer will make a mistake on building an engine every once in a while. Likewise, with thousands of parts, a bad component may end up in the finished engine. Your warranty exists for this reason. Most manufacturers will stand behind their products in cases of bona fide fault.






MarineDiesel User Poll – Warranty



This week’s user poll is related to engine warranties. We are asking our readers the following two questions:

[socialpoll id=”2222590″]

[socialpoll id=”2222591″]

We thank you for your opinion and feedback. Please send a note to us at if you would like more input or have any concerns.




Can I use a Nitrous System in a Diesel Engine?


Yesterday, an interesting article was published on Yahoo Automotive regarding the use of Nitrous Oxide Systems (NOS) in gasoline engines, and whether the increased horsepower was worth the expense.

Nitrous is one of the most divisive topics in the world of performance driving. Some think that it’s a sure-fire way to turn any engine into a hyper-powered brute. Others dismiss it or claim that it’s an excellent way to destroy your car. As with most things, however, the truth is in between the extremes. To see why, let’s take a closer look at the subject.


It all Comes down to Oxygen

Try to fire up your barbecue grill in the vacuum of outer space and what will you get? Nothing. That’s because oxygen is necessary for combustion to occur. Without this vital gas conventional engines can’t function. That’s why the Apollo astronaut’s moon buggy and the Mars rovers both ran on batteries.

The more oxygen and the more gas you can cram into a cylinder, the more power you’ll get out of an engine. But it turns out that earth’s atmosphere is only 21% oxygen. This fact is vital to our continued existence, as pure oxygen would make the planet blow up as soon as someone lit a match. In terms of automotive performance, however, it puts a limit on how much power can be created using plain old air…

Here’s a link to the complete article

MarineDiesel specializes in diesel engines for high performance vessels. Would a Nitrous system improve the performance on our engines?

The answer is, “Possibly”, but mostly “No”… And, you will certainly void your warranty if you try it.

There are a very few high performance diesel engines in the marine market, almost all designed specifically for racing, that have NOS installed. In virtually every case, these engines were intended to be used under race conditions, with very short life cycles, and for very short periods of time.

Modern diesel engines are designed with a turbocharger and electronic controls that already bring the optimum amount of oxygen into the combustion chamber. Altering this mix, with a NOS installed, does several things:

1. Increases the exhaust temperature.

2. Produces excessive smoke (The fuel mix becomes too rich)

3. Increases the heat in the cylinders, producing excessive wear on the pistons and rings.

4. Increases the heat in the turbocharger.

Now, in a diesel engine with a standard turbocharger, not VGT, the fuel mix is able to be manipulated, just as with a gasoline engine. With our VGT engines, we have already optimized that mixture, and the addition of Nitrous simply results in an over-fuel state.

Therefore, though you would receive a very little amount of additional power from the engine, you would seriously decrease its’ service life, and greatly increase the cost of ownership, especially given that you have just voided your warranty.

So, the short answer is, “Don’t Do It!”





Was this a warranty claim? No!



We will occasionally receive a strange warranty claim every now and then. They are usually ending up relating to maintenance or minor configuration issues. Take a close look at the above picture. Warranty? No.

This is the result of pirate attack in Africa. Though MarineDiesel engines are built to withstand the toughest conditions, an explosion by a RPG is not covered (Though we did quickly expedite a replacement engine in this case) under warranty. Our engines are used in some of the most difficult regions in the world. Quite a few of our customers are involved in the combat of piracy, and as manufacturers, it is our responsibility to provide them with the most reliable equipment possible. This responsibility extends way beyond a simple discussion of cheapest price.

For those curious as to what the rest of the boat looked like… It really sends a strong message.






Ask Professor Diesel 05/12/2014 – Kerosene

This week’s question comes from Mark in the USA:


Professor Diesel:

In my area, kerosene is considerably cheaper than diesel. Will my MarineDiesel engines run on kerosene without being damaged?


Kerosene is sometimes used to thin diesel to help prevent gelling in cold weather, but it also reduces the fuel’s lubricity as well.

Diesel engines are highly tolerant of different types of fuel formulations and can run on just about any oil-based fuel, but that doesn’t mean they should or that there is any benefit in doing so. Diesel engines are more or less indifferent to fuel types, but the emissions and injection controls on MD engines could possibly be damaged by using any fuel other than recommended in your model’s manual. Additionally, this means that you risk your warranty and performance levels would suffer, as the engine’s ECU is programmed at the factory based on fuel type, to optimize your performance. Since emissions levels produced by the engine are also based on a specific fuel use,  you could also find yourself violating local laws regarding air quality.

For illustration purposes only, the following is a  list of fuels that generally can be burned in a diesel engine (Though “can be burned” does NOT necessarily mean “should be burned”):

  • Diesel #1
  • Diesel #2
  • Diesel #4
  • ULSD (Ultra Low Sulfur Diesel)
  • Biodiesel (from B5 to B100)
  • Kerosene
  • Home heating oil
  • Civil jet fuel (Jet A-1, Jet A, Jet B)
  • Military jet fuel(JP-4,JP-5,JP-8)
  • SVO (Straight Vegetable OIL)



Maintenance Tip of the Week – Starting Aids 05/05/2014


Maintenance Tip of the Week


When an engine will not start, it is tempting to use starting aids, such as ether, to force the engine to start.


Not only is this practice often dangerous, it will instantly void your engine’s warranty. Don’t do it!