Can-Am Defender Problems – Solving Common Issues

Can-Am is one of the largest utility vehicle manufacturers in the market. Their selection of Utility Terrain Vehicles, or UTVs, poses stiff competition to its counterparts, such as Polaris. Their most versatile and work-tailored vehicle, the Can-Am Defender, is one of the top sellers in the business. However, it does not come without its share of problems, such as:

• Design Flaws
• Starting Issues
• Quality of Assembly

We looked at the most common problems experienced with the Can-Am Defender in each category and sourced the best practices to overcome them.

Design

While the Defender is a versatile and practical utility vehicle for work and recreational uses, its design has several often-overlooked problems.

• Air Intake

Designed for rugged terrain and heavy use, you would think the Defender should handle constant operation in rough terrain. However, owners have frequently complained about one common issue: the intake system. 

An air intake is essentially the breathing mechanism for an engine; it's how air gets in. The stock location of the intakes was poorly placed, and many owners using their Can-Am in dusty or sandy conditions have experienced problems related to the intakes. This simple choice in design can lead to countless other - more expensive - problems down the road.

When too much dirt and dust get onto or into the filter system, it can significantly restrict the amount of air reaching the actual cylinders of the engine. This "rich" mixture (too much gas and not enough air) can cause starting, idling, and running problems, because the engine is not operating at its proper Air/Fuel ratio. 

However, this design issue can cause much bigger problems. When dust, dirt, grit, or grime gets past the filter of an intake system, it is directly fed into the engine cylinders and is likely to cause extensive damage. Small sand and dust particles inside a running engine can tear it up from the inside, often ruining it completely.

The fix for this problem is relatively simple: upgraded filters. If you choose to buy an upgraded filter system, these two products will have your Defender running as if on pure oxygen:

• Snorkel/ Pre-filter
• Oiled filter

A snorkel acts for an engine the same as it does for a swimmer, providing access to clean air through a tube. A vehicle can use a snorkel to limit the amount of water, dust, and mud entering the engine through the intake.

These snorkels can be paired with a pre-filter as a first barrier protecting the engine from larger pieces of dust and sand. This will keep the primary air filter clean and provide efficient airflow to the engine.

The last component to upgrade in this system is the primary intake filter, where many people opt for an oiled filter. This offers a tacky surface to catch contaminants, like fly paper. This allows premium filtering while maintaining airflow smooth enough to keep your engine running effortlessly. 

These upgrades are commonly used to efficiently address the problems caused by the placement of air intakes, one of the Defender's most prominent design flaws.

• Safety Limit Switch

While some people use the Defender exclusively for fun, it is also a popular choice as a snow plow vehicle. For those trying to get the full work potential out of their Can-Am, an oversight in the placement of the safety limit switch can cause inconvenience and aggravation. 

The safety limit switch is used when attaching machinery- most often plows- to the Defender. It acts as a controller for lifting cables and prevents damage to the equipment and the Defender itself.

Unfortunately, Can-Am placed this important control under the hood of the Defender, not exactly an easy spot to reach from inside the vehicle. This prevents efficient work and raises safety concerns as people have bypassed the safety of this control just to avoid the inconvenience.

However, simple rewiring can relocate this switch to the interior of the cab, sparing frustration with the design. You can easily rewire this yourself with basic electrical knowledge or purchase a kit for it.

Starting Issues

• Battery

Being a UTV, the Defender is not exempt from battery issues. The battery is responsible for powering the engine starter; if dead, the Defender can no longer start. Some common reasons for a dead battery include:

• Poor Terminal Connection
• Old Battery
• Parasite Sources

While a bad wire connection or excessive age will cause a dead battery in every vehicle, the Defender is especially susceptible to battery draining via parasite sources. Many people modify their Defenders with light bars, machinery, speakers, and other electronics. If done incorrectly, these attachments can cause power loss in the battery.

In most situations, simple wiring maintenance is enough to keep a battery in good condition. You can get services from a professional to add modifications to your Defender if you are unsure of the specifics and effects.

• Oil Level

However simple it may be, the Defender is not immune to basic maintenance needs. Starting issues could be a case of low oil or an oil leak. They often leak oil, lose levels rapidly, and sometimes even leak oil into the fuel. An oil check is always a good place to start if your Defender has starting issues.

• Fuel Pressure

For an engine to run, it needs fuel to get into the cylinders. While older engines traditionally used carburetors (a mechanical part to mix air and fuel), most modern engines use fuel injectors. The Defender is no different, although its fuel delivery system is not known to be flawless.

If the fuel delivery system is not working as intended, less gas will be released into the engine than needed. This results in a "lean" mix (too much air and not enough gas), which can easily cause a starting problem.

If fuel and oil levels have been checked and the battery is not dead, you can check the fuel delivery as a reason your Defender won't start. To check the fuel injectors and fuel pressure:

• Turn the key but do not start the vehicle
• Listen for the fuel pump
• If you hear the fuel pump, you can test the pressure with a tool. Pressure should hold near 51 PSI and not immediately dip
• If you do not hear the fuel pump, this is likely the cause of your Defender not starting

Although your Defender may start, that does not guarantee your Air/Fuel ratio is not too lean or too rich. Trouble idling and dying engines are telltale signs of a possible fuel or air-related problem.

Quality of Assembly

• Doors

One of the most common complaints on the Can-Am Defender is the horrible performance of the doors. While the design itself is a loved style, the execution of the suicide doors is not only a show of low-quality assembly but is sometimes a safety hazard.

"Suicide Doors" is a term used for a style of automotive door with hinges near the rear of the door instead of the front. Though initially used on horse-drawn carriages, it was brought to mainstream fame in high-end luxury cars and has proven to be a successful design. 

However, the build of the Defender's doors is noted to be not only low quality but, at times, dangerous. Flying open randomly is clearly not an attribute you want from your door, though it has been seen by some owners. Also reported are a rattly build and imperfect seals, allowing dust and mud to enter the cab. 

This concern can be eliminated by a set of aftermarket doors made by a third party. While you can easily replace stock doors with significantly superior ones, this shouldn't have to be the default. The assembly is a problem for many Defenders and is an area Can-Am should reassess.

• Noise

While a UTV is not expected to be quiet, rattling shouldn't be the first sound you hear. Many owners have complained about the windshield, noting it squeaks and rattles in a way a piece of safety equipment shouldn't. This can be remedied by fidgeting with the handle used for opening the windshield, but it shouldn't be necessary.

Additionally, a lot of owners complain about the noise the brakes make. The brakes will squeal and grind at slow speeds or when coming to a stop. Although this does not impact the performance of the Defender, it is a nuisance. You can fix this by taking it to a service center, although many people see it as an unnecessary expense. 

Finally, many owners report belt squealing- when belts on the engine make high-pitched noise. Common on any engine, this can be caused by a variety of reasons such as:

• Improper tension
• Contaminants
• Worn Belt

This is not a serious mechanical problem but can get annoying if you need to be in the Defender for extended periods. If tension is the cause, a simple adjustment could fix the problem. Belt dressing is also used to stop this but will likely only solve the issue if contaminants such as dirt and oil cause the squelch. A replacement will stop the noise if the belt is old, worn, or cracked.

Conclusion

The Can-Am Defender is a popular UTV for both work and recreation. While widely owned, it has shortcomings. From starting problems to design and quality concerns, the Defender has its fair share of complications. However, if you are willing to work on fixing these often simple problems, the Defender can be a practical and reliable choice for work or play.