Is It Worth It? Some Cummins M11 Problems You Need To Know

It may be reliable and sturdy, yet there are most certainly Cummins M11 problems that can impact your overall experience. 

This is why it is important to know what you can expect from this engine before investing your time and money with it.

If you are looking to purchase this engine and want to know what you can get from it, make sure you check out this comprehensive review on the Cummins M11 and some problems that may come along. Let’s get right into it.

cummins m11 problems

Common Cummins M11 Problems

Overall, the Cummins 11 should last for about 850,000 miles or so. However, this is only possible when you take care of the motor. But for the most part, it is a dependable engine designed to last a long time.

In terms of longevity, the M11 engine is reliable. In fact, there are folks who have owned this truck and have gotten more than 1,000,000 miles on it with very little problems. It is, however, possible when you do not overload the RV to prevent the motor from working harder than it should.

Do keep in mind that it takes more than simply changing your filter and oil as a way of maintaining the motor. There are also other things that need to be done to ensure the longevity of your M11 motor.

But generally, the M11 motor is a good motor. In fact, it is one of the finest engines by Cummins. Despite the flaws that it comes with, you can expect this motor to last a long time, sometimes even up to 800,000 miles.

On the other hand, there are those who complain that it is a bit underpowered. When you use the motor to haul too much weight, then it can be a bit low on power. Yet, it should not be a hindrance at all for people who are looking to use this truck motor for commercial and industrial purposes. There are no concerns about it leaving you stranded when driving up steep mountain passes and roads even with a hefty load. The climb may be slow, yet it could definitely do the job.

However, there are some problems to take note of that may be important to know just to understand what you can expect from it. 

For instance, there may be no codes found, or data ports may sometimes fail to respond when you connect it to your scanner. The most common reasons why this happens include a failed component, broken wires, or loose wiring or connections.

Moreover, there are some cases when the motor starts to skip or blow dense white smoke from the exhaust system. These issues may be linked with over fuelling or some oil contamination problems.

Over time, the wire harness will need to be replaced. When you have gone past the 600,000-mile mark, it may wear out. Unfortunately, a wire harness replacement can be rather expensive. Expect to pay about $600 when you need to replace this component.

The reason for such steep cost is that there are plenty of wires that need to be replaced. These wires are also connected to other wires. Hence, the process can take about 6 hours or so when you perform a replacement work. So, the labor cost can be quite expensive, as well.

But there are also cases when you may need to have the injectors repaired. Over time, this component may present some issues. Thankfully, it should not take a lot of time and work to fix it. In addition to this, it is important to inspect the O-rings on your filter. Make sure that there is no piece that has gone missing or has become worn out. 

O-ring issues may not be so common, yet these are most certainly easy to fix. The cost of replacing O-rings is also reasonable, unlike with other bigger components. You may also want to check out the mechanic to consult for such repairs, so you will not end up spending more than you should when getting your motor repaired.

Is The Cummins M11 Worth It?

cummins m11 problems

Based on most owners, the Cummins M11 is most certainly worth the price you pay. In fact, many RV discussion groups and trucker forums claim that they are able to rely on the Cummins M11 motor. This is a dependable motor that is worth the price you pay and despite the smaller size, it can handle as much as 80,000 pounds when traveling at highway speeds.

It is a compact engine, yet it is definitely reliable and worth the price. There may be flaws to consider, yet these do not outweigh the positive features of the motor.

For the size, it is a good value for the money. It can last when well taken care of and maintained well. Just be sure to ensure the integrity of the engine as it is crucial when it comes to maintaining its lifespan and good performance.

As for the horsepower, you can guarantee that it is more than enough to help you reach your destination. Depending on the motor’s model number, you should be able to see as much as 330 HP on a 2000 RPM. That is definitely more than enough power that you need when you want your vehicle to go over those steep and challenging mountain passes without any problem at all.

However, when you need to haul about 80,000 pounds over the same type of mountain road, the motor may appear to be quite underpowered. You can go over the highest point but then it can take longer. On the other hand, there should be no issue at all with a lighter load that is about 10,000 pounds. 

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So overall, for a small engine and with a decent fuel economy, the Cummins 11 is indeed worth it and a decent motor for the price you pay. With very little problems and considering its long lifespan, this motor should be a good bang for your buck.

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