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Top 11 mistakes (not to make) when buying your next diesel engine

As featured in Australian Transport News and Deals on Wheels, written by the team at Alldiesels Australia Few periods in history have offered quite so many challenges for heavy-vehicle fleets and operators of industrial machinery in keeping their assets operational. These times have demanded the utmost flexibility in operations, maintenance and upkeep – not least with diesel engine needs. Over its 25-plus years of experience and after helping tens of thousands of Australians and Australian businesses keep their operations running, second generation family- owned business Alldiesels Australia is well placed to be an authority to both the good and the bad of buying a new, used or rebuilt diesel engines, and shares insight into challenges. Here, Alldiesels Australia general manager, Byron Ansiewicz shares insight into some of the most common pitfalls we see fleet-owners and managers making when keeping on top of their diesel engine requirements.

Top 11 mistakes (not to make) when buying your next diesel engine: 1. Thinking the day you have a problem, you will be able to buy the exact replacement engine you need

Particularly in the current environment with supply chain issues and slower and more expensive freight, there is less stock on the market and longer lead times. This is a challenge facing nearly all industries, and the diesel engine industry is not immune.

Dealers of diesel engines – [even the big branded dealers] are finding it more challenging to get access to limited global supply. It is not uncommon for people to be told they need to wait three-plus months (or longer) for an engine once an order is placed if you are sourcing a new engine. A rebuild can be a similar story with limited availability of parts and slower freight. Booking your engine in to be rebuilt is only part of the equation, sourcing and getting the parts delivered for the build can take weeks or even months depending on availability and freight.

If you anticipate you are going to have requirements for a replacement engine or you require a rebuild, the sooner you have that discussion and source the engine or book the rebuild, the better placed you are going to be in the long run. Having an engine sitting in surplus is often a lot cheaper and less stressful for a business than being down on a piece of equipment or machinery for an extended (and often uncertain) period of time – and it always happens right when you need it. Not only does it cost you money having the machinery out of action, but it can also let down your customers if they're relying on a commitment that has been made to them or mean crops perish (for a farmer for example) or you miss a contract if you don't have an essential piece of equipment working when it needs to.

Sure, holding an engine in inventory carries expense, though, for a lot of Alldiesels’ customers, having a critical piece of machinery out of action for months is a lot more expensive. If you have an engine that is getting tired or looking for your next engine, get in contact with us so we can help you minimise that costly downtime.

2. Only contacting the new dealers and not understanding the industry

Another mistake would be only contacting the branded dealers and distributors, and not considering that there is a market of independent engine sellers. This is true for both new and used engines.

Alldiesels is the largest independent seller in Australia that specialises in heavy US & European diesel engines, though there are also large dealers that specialise in Japanese makes or lighter engines that are worth exploring if those are your requirements.

Similar to a branded car dealership, branded dealers such as Caterpillar or Cummins are often limited in the stock they can supply [generally new engines], and have their hands tied to only official channels so will often have a less extensive range, not to mention typically being limited to one brand. An independent dealer such as Alldiesels Australia has no such restrictions. Engine brands we deal for example in include: Caterpillar, Cummins, DAF, Detroit, Iveco, John Deere, Mack, MAN, Mercedes, Perkins, Scania, and Volvo amongst others.

This ability to deal in various brands means we have expertise across a broader range of different makes as well as options for used engines and rebuilds, so we can provide unbiased advice and we are not limited to just one brand or solution.

We often will hold more supply of new and used stock than many of the branded distributors in the country, and we can source new, used and rebuilt from all over the world (as well as re-build our own engines for inventory or to customer specification), which means we regularly have access to engines that a branded dealer will not have.

3. Not understanding the difference between buying from a wrecker vs engine builder

A wrecker or dismantler will often buy a wrecked vehicle or piece of machinery, knowing that they need to dismantle and sell each component of that wreck, including the engine, to make a profit.

A wrecker is, more often than not, not an engine builder. They will likely have some mechanical understanding, though, typically, will not be qualified or have the expertise or specialised equipment to be able to properly inspect an engine, run the engine correctly for diagnostics and test an engine under load in proper simulated conditions.

Basically, this means when buying from a wrecker you are often buying blind - which carries significant risk given the size of the investment in both time and money that is often being made with the purchase of an engine. A wrecker also may not have the capability to resolve warranty issues if they arise. Expert advice and buying an engine that has been thoroughly inspected and tested under load will save you both time and money.

One should always exercise caution when buying a used engine to ensure it has been properly load tested. We often see used engines advertised for sale that have been "run" but not load tested. Simply running an engine at idle, or even through its rev range with no load, is as good as useless for diagnosing potential problems.

To test an engine properly you need to be able to get everything up to temperature and operating under load, as that is when most issues become apparent and can be diagnosed.

Essentially, the key difference behind buying from a wrecker as opposed to an engine builder/dealer such as Alldiesels Australia is you are buying an engine from experts, that has been thoroughly inspected and tested, meaning you have peace-of-mind the engine will do what it needs to do after you go through all time, money and effort of installation and fitting.

Similarly, most workshops are what we would term "a Jack of all trades, and master of none", they do a little bit of everything - from body repairs, to general servicing, and the odd engine build here and there - perhaps building a few engines a year, and rarely coming across the same engine make & model as they just don't get the chance to work on them very often. At Alldiesels we have a team of specialised engine builders and sales and support team who literally build engines all day, every day. We don’t dismantle or service trucks or fix panels. We just diagnose, inspect and build engines day in, day out. Our team builds in excess of 150 engines every year! The simple fact is that this specialised focus enables us to be very good mechanics when it comes to testing, diagnosing, repairing and rebuilding engines.

4. Not realising that the same engine often has multiple specifications

The same engine make and model will often have a number of different specifications. For example a Cummins M11 will come in the base specification, as well as Celect or Celect Plus variants.

These different specifications can be due to updates over the time the engine was manufactured, have different horsepower ratings, or have differences that make them suitable for different applications (automotive or industrial for instance).

Matching the serial number from your existing engine is the best way to ensure you are buying the correct engine.

5. Not considering the difference between new, used and rebuilt

There are positive and negative considerations to weigh up when deciding whether to buy a new, used or rebuilt engine, such as warranty, history, budget and time-frame. Sometimes your options may also be limited by what is available at any particular point in time if you urgently need to get a piece of equipment moving again. Downtime is generally very expensive for our customers and the cost of sitting idle can add up quickly. Again, planning ahead is the best way to mitigate this.

The decision for a new, used or rebuilt engine is unique to each operator and comes down to the operators circumstances and requirements for the engine, though it is worth considering which of these options is relevant to you and your business.

6. Not all rebuilds are created equal

When comparing rebuilt engines, it is critical to ensure you are comparing apples with apples.

The term ‘rebuilt’ does not have a single generic meaning in the industry. Often we will see engines marketed as ‘rebuilds’ that have had a very limited build and few new/replacement parts. Buyers should be mindful that if a rebuild seems "cheap" compared with other options on the market there is usually a good reason for it. Typically it will be due being a combination of a less extensive rebuild, and using lower quality replacement parts. If you see a "rebuilt" engine that is significantly cheaper than another advertised rebuild, it is most likely that the two builds are vastly different. Time and time again we see advertisements for a ‘rebuilt engine’ that might only have had partial re-work, such as: some but not all of pistons and liners replaced; cylinder heads not having new valves and springs fitted; or fuel systems not being overhauled. Often, we see components such as turbochargers, injectors and air compressors not being rebuilt or replaced with new in these ‘rebuilds’. These factors all obviously affect the price. There is nothing necessarily right or wrong with purchasing a partial or full rebuild, but no two rebuilds are the same and often buyers are not aware of the differences.

Most importantly, the buyer needs to understand the extent of the rebuild and the quality of the parts used in the rebuild. - Have genuine parts been used? - What is the quality and reputation of the parts if non-OEM have been used?

- What are the warranties that come on the various components of the rebuild?

There is a long list of questions that a buyer needs to be asking to know the extent of a rebuild. 7. Buying with no warranty (or a warranty not worth the paper it is written on)

Typically this will apply when buying from a wrecker or if buying a one-off piece from a small seller of an engine surplus to their requirements. Anyone who has operated equipment with diesel engines, knows that from time-to-time engines break down and things go wrong. As much as we put an immense amount of time, effort, energy and resource into inspecting and testing our engines prior to sale - sometimes things do go wrong. It is an unfortunate part of business, but most importantly we have processes in place to support our customers when these things happen. When buying a diesel engine, you need to ask yourself about the supplier: - What is the fallback if something does go wrong? - How are they going to make it right for you if something does go wrong? - Do they have the financial means, the expertise and/or the appropriate insurances?

Buying from a trusted business such as Alldiesels Australia with decades of experience, and track record of supporting tens of thousands of Australian customers provides for a lot of peace of mind that a warranty will be honoured and expertise is available when unforeseen challenges arise.

8. Not understanding that the same engine can be manufactured by multiple manufacturers

Often engine manufactures will share the research & development cost and production costs for engines through collaboration projects between two or more manufacturers. The result is the same or very similar engines are then sold under different brands. For example the Mack MP8 and the Volvo D13 are the same engine with only a different rocker cover and inlet manifold, and are interchangeable in the vast majority of applications.

There are dozens of examples of this across nearly all manufacturers.

If you are looking for a replacement engine, you can often find an identical specification engine that has been built in the same factory with a different brand marking on that engine. But if you walk into the Volvo dealer, do you think they are going to tell you that there is an identical engine that you can buy from a competitor when they only have Volvo engines to sell?

Tips and knowledge like this can save you time and money on sourcing the right replacement engine to get you back on the road faster.

9. Not understanding the tax benefits available

It is always worth speaking with your accountant when buying an engine to understand the tax benefits available from purchasing a new, used or rebuilt engine. If you are financing the engine for your business, the interest is often a deductible expense too.

10. Trying to import an engine yourself

The internet has opened the door for people to try to self-import engines. We couldn’t tell you how often we hear of this ending in tears. We import literally hundreds of engines every year from all over the world and have been doing so for decades; we know first-hand it isn’t for the faint of heart.

With our buying power and ongoing relations with suppliers, we are able to source engines globally and domestically, significantly cheaper than a one off-buyer. We also take the risk of landing the engine in Australia, which includes that if the is no good on arrival, or doesn't pass our inspections, it is not our customers problem. Pre-Covid, our expert buying team has spent decades flying all over the world, sifting through yards, meeting and building relations with reputable suppliers to enable us to continue to reliably source the best engines even in these times.

As a do-it-yourself buyer trying to figure it all out, you're buying unseen and untested from oversees of an unknown buyer. There are the added logistics (time and cost) of trying to ship an engine into Australia, pass through quarantine, and then what is your recourse when the engine turns up in Australia after waiting for months and it is either the wrong specification, not in the condition you were told, has been damaged in transit, or doesn’t run properly? Is it all worth the time, effort and uncertainty when you can buy from a trusted Australian supplier such as Alldiesels Australia (and rely on Australian consumer protection laws at very least), with stock landed in Australia and tested, with warranty and a team of experts on the ground? 11. The cost of sitting on a decision and down-time

One of the most costly mistakes we often see people making is simply sitting on a decision.

Sure, if your engine has failed on you or is getting tired, no-one looks forward to the expenditure on the replacement, but it’s a part of business and hopefully you have planned contingency for this.

If you have a piece of machinery sitting there because the engine has given up or the engine is getting tired, there is often a time lag between finding the right engine, getting that engine delivered and then installed, and getting the machinery or piece of equipment going again. That downtime can cost hundreds or even thousands of dollars for every day that a decision-maker sits on their hands and don’t get things moving along. So making decisions and keeping things ticking along is often the less expensive way to go about it in the long run.

Get in contact - we're ready to assist! If you're looking for a diesel engine or need assistance on your diesel machinery, don't sit on your hands and cost yourself money, get in contact and let us assist you get moving again. Our team is standing by and ready to help: Email: Phone (fastest way for assistance): 1300 822 844 Alternatively, submit your details on our website and we'll be in touch as soon as possible - click here


Philip Brown
Philip Brown
Apr 28, 2023

Just reading through all the promises above makes my blood boil. I purchased a used engine from All Diesels, workshop tested, they said . It burnt approximately 1.5l of oil per hour, ran it for approximately a week to get a urgent job done.

Went to another one day job ,the engine ran for about half an hour then seized . there was plenty of oil in the sump. The engine blows lots of black and white oily smoke and won't start.

All Diesels have sent over a ring set to solve the oil consumption problem. Due to their staff sending the wrong customs paper work the ring set has been held by Customs in Auckland since February.

I contacted…


Sandy Shaw
Sandy Shaw
Feb 14, 2022

gday guys ..if you come across an international tractor motor 584 first built in 8o's please let me know

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