Is The Maxxforce 7 Diesel Engine a Piece of Junk? (Problems)

Not everything engineers make is golden or will pass the consumer test. What some people think is a good idea or a great upgrade, just doesn’t work out that way. All you have to do is look at Microsoft XP and Windows 7 to see examples of this trend. The upgrades on future versions were not so good.

Is the Maxxforce 7 diesel engine a piece of junk? The answer to this question will depend on who you talk to. For some people, they lend an understanding attitude and point out some valid reasons why things went south on this engine. Others are not so kind and are less tactful and spell out all the problems this motor comes with.

To learn more about the Maxxforce 7 engine, just continue to read our article. It will provide as much information as possible so you can make up your own mind on this issue. From what we have heard, the production of this engine has been discontinued.

What is The MAxxforce Engine?


This was supposed to be a grand trucking engine that was supposed to help trucking companies get more power and better efficiency. The engine itself was a V8 and it carried a lot of equipment next to it. There were a remote mounted air compressor and other parts that made this a complicated engine to use and work on.

From the get-go, there seems to have been nothing but problems with this motor, even though there have been some very satisfied customers. Those problems have mostly pointed to the exhaust gas recirculation-only (EGR) engine that Navistar used instead of a better system.

The company did eventually switch to the Cummins selective catalyst reduction (SCR) technology but not until the EPA threatened to fine them almost $4000 per engine sold (once the company used up its emission credits).

Overall, it was not just the ECR that was the problem. The design of all its different parts caused a lot of problems for both truck company owners and mechanics. The change in design came too late for many of them.

Basically, the engineers who designed it thought they were coming up with a better idea. Unfortunately, what looks good on paper and blueprints does not always work out in reality. Far too many customers and owners have suffered from the many parts failures that have occurred while the engine was in production.

Maxxforce Engine History

The concept that produced this engine was a good business decision. International wanted to make their own engines in-house in order to have a steady supply of engines. Often in any industry, if a company buys from another company the buyer is at the mercy of the problems that would shut production down at the second company.

Also, profits go out the door. This way they get to free themselves from different problems from outside companies while making sure the company stays profitable. Unfortunately, this did not happen when the company began to make the Maxxforce 7.

This was an engine that was put into production around 2003 and some say it was discontinued in 2012 while others say it survived for another 4 years. The engine had some of the DT 466 inline 6 applications helping the 7 to get off to a great production start.

Between 2003 and 2010, Ford was the main consumer and user of this motor. That is until they started using their own engines for the same vehicles. The specs were good as the engine could put out 350 hp at 3000 rpm and 650 ft-lb torque at 2000 rpm. Other versions had the hp down to 200 to 230 and a little lower in the torque as well.

The cylinder block was updated since 2003 and the company used a compacted graphite iron material which made the block stronger. However, this upgrade and others did not stop the problems from taking place.

Who Makes Maxxforce Engines?


The company that made this engine is called International Truck and Engine but it is a subsidiary unit under the parent Navistar International. Before Navistar bought out International, the latter company had a stellar reputation for its trucks and motors.

Unfortunately, the Maxxforce 7 almost single handily crippled the company and deprived it of millions of dollars not only in lost profits but in lost lawsuits. lawsuits plagued the company over the years those motors were installed in different trucks, buses, and other vehicles.

It took a threat from the EPA before Navistar changed the design on the engine as well as replacing it with a competitor's motor. If you have a vehicle under the Navistar or International brand name, and it has a Cummins motor, Navistar did not build it.

One wonders how the company thought that this was a good investment as the design was plagued with problems from the outset. They willingly chose the wrong emission system which is blamed for most of the issues that occur on these motors and had to be forced to buy another one from their competitor.

That was a humiliation that Navistar had to overcome. It took a lot of hard business work to right the company after the huge losses they experienced making this engine. But they have made the right changes, or some people hope, and were soon back to making a good profit.

When Did the Maxxforce Engine Come Out?

It was 2003 when the first of the Maxxforce versions were produced. How long it was in the research and development stage is anyone’s guess but it may not have been long enough. While that seems to be a harsh thing to say, very few people were happy with this motor.

There may have been later versions of the 7 and there is said to be an engine from 8 to 15 and those versions most likely came out from 2010 to 2016. But for some reason, Navistar or International could not solve the many problems that were built into this motor series.

No matter which version it put out it seems that a lawsuit was generated. the N9 and N10 were to replace all Maxxforce engines starting about 2014 approx., except for the Maxxforce 7 and the DT engines.

Yet, even with the name change, it is said that those new motors are basically the same as the Maxxforce series. The only difference between the new N9 & 10 and the Maxxforce is that the former engines used the Cummins SCR emission system and not the Navistar ECR system.

There are people happy to see the Maxxforce disappear from production as it was an engine series that created nothing but problems for the company and its owners.

Maxxforce Engines Discontinued


Yes, this whole series has been discontinued, according to the research we have done. The only problem is that the dates the company stopped production are not set in stone. By that, we mean that we have seen at least 3 different years the motor was to have been discontinued-- 2012, 2016 & 2014.

The name on the replacement was as we already mentioned the N9 & N10 but according to some reviewers, it is the same Maxxforce engine but with a different emissions system attached to it.

People are not sad to see it go as the list of complaints owners had about this motor would fill up the rest of this article and then some. Our research has turned up very few owners with anything nice to say about this motor.

That is not to say that Navistar did not produce some good units. Some owners were quite satisfied with the version in their vehicles. others have said the same positive remarks but they also clarified those remarks with the hard statement that they would never buy another vehicle with the same engine in it.

According to some people, the EPA did fine Navistar for the poor emissions this engine put out and that was what finally forced Navistar to cease production. The Maxxforce 7 never could meet emission standards and that was one of its biggest problems.

Maxxforce Engine Class-Action Lawsuit

Where do we start? One website from a lawyer’s office representing 3 trucking companies filed 3 lawsuits against Navistar but the date of those filings is not known. There is no date for when the article was written but it is on a 2021 copyrighted web page.

Then another 6 companies filed their own lawsuits using the same law firm. It seems that the Maxxforce 7 and other versions have produced more lawsuits than any other engine in history. This is not to mention the $135 million class-action lawsuit that Navistar recently settled.

The winners in this 2019 settlement can either get a $2500 no-questions-asked payout or a $10,000 rebate on a new truck. The latter option really does not affect the company’s bottom line as it would not be out any cash.

But this settlement is not the only financial woes that hit the company during the existence of this motor. The lawsuit makes room for an up to $15,000 reimbursement program and the company has also lost over $700 million in research and development costs.

On top of those expenditures, the company had to pay out $500 approx., to buy back trucks from angry customers and then resold them at a loss. With the warrant expenses, Navistar paid out over $1 billion.

As you can see, this engine has been a financial nightmare for the company. It is no wonder the company wants to put this tragedy behind them. The cost of this engine cannot really be measured as lost customers may never return.

How to Identify a Maxxforce Engine


The first place to look would be the serial number that is imprinted on the block or some other engine part. That will lead you to a list or should lead you to a list, stating which engine the number belonged to.

Then the owner’s or service manual should have the name of the engine under the hood of the vehicle. That label should be there along with some of the specs. Not to rub salt in the wounds but you can also identify the engine by the emissions technology that came with it.

If it had the ERC from Navistar, you know it was an early model of the Maxxforce 7 and not one of the few that had the Cummins SRC technology. The latter came out sometime around 2012 to 2014.

Finally, you can identify the engine by the vehicle model that had it under the hood. This list comes from this link and all the vehicles should be in the 2008 to 2013 production years:

  • International Prostar and Lonestar, which are heavy - duty, long haul tractor-trailer trucks
  • International Transtar, a heavy - duty, regional haul truck
  • International Workstar and Paystar, severe duty trucks used for construction applications
  • International Loadstar, a severe - duty cab forward truck used for various applications, including garbage trucks and airplane refueling trucks.
  • All of the Trucks are U.S. Department of Transportation Class 7 and 8 trucks, the largest, heaviest, and most powerful trucks on the road.

You may find some in a few Ford trucks as it has been said they used this engine in some of their models.

How bad are Maxxforce Engines?

Judging from the complaints and the huge financial losses experienced by Navistar, the motor was quite bad. The list of problems is immense and a couple of examples are sudden engine shutdowns that made drivers use emergency tactics to avoid accidents & exhaust and coolant fumes entered the cab of the truck creating a poisoning risk.

Some mechanics have stated that the engine needs to be scrapped at 150,000 miles and a rebuild is not worth the effort or the money. Those RV owners who had these engines were not welcoming this news.

Other people gave the one-word answer when faced with this question-- run! In other words, stay as far away from this engine as possible. That seems to be the general consensus of Maxxforce 7 owners.

Although, there are defenders of this engine who try to look on the bright side and say it was other versions of this motor that was the problem. In our research, that was not the case. All the Maxxforce series, including the 7, were bad.

These problems were not limited to big rigs. School buses also had problems including losing the high-pressure fuel pumps, diluted engine oil, and lost oil pressure and the contaminate was the diesel fuel. This is just the beginning of problems with this engine.

Is the Maxxforce 7 Diesel Engine a Piece of Junk?


There is a group of people that consider the Maxxforce 7 a very good engine and they are quite satisfied with it. They may have gotten great units and were the lucky ones. Their side of the story cannot be dismissed from the situation but they are also the ones that do not get the benefits from the class action lawsuit settlement.

They may not have paid out a lot in repairs. Some have reported that they had no real issues with the motor so some good ones did exist. However, the list of problems mentioned above is just the tip of the iceberg of the problems that came with this engine and its counterparts in this series.

When a company loses over $2 billion, their reputation and 50% of their market share just because of one engine, then those good stories do not make up for the loss. There are not enough of them to overcome such a debacle.

Basically, the motor was a piece of junk based on the evidence we have seen and all the reports that we have read. The high cost of repairs that have to be paid by the owners and Navistar’s failure to replace the faulty emission system with a better one don't lead anyone to a better conclusion.

Why are Maxxforce Engines So Bad?

This is a loaded question and the finger cannot be pointed to any one problem, there are just too many factors involved that make this engine bad. But if you want a place to start, two specific areas should be looked at.

First, the overall design. It was complicated, had too many devices attached, and the hoses and other parts interconnected in unusual ways. The motor was a very cluttered engine and it was a very labor-intensive design.

By that we mean it took forever to remove all the extra parts before the mechanic could work on the actual problem. That wasted a lot of time and boosted the labor costs.

Second, the emission technology that was originally green-lighted for this motor was faulty. It was a bad design and it did not work on all models as well as it could have. We only listed two of the problems earlier with this system.

The fact that the EPA had to force Navistar to replace their emission system with a competitor’s tells you how bad the design and operation were. We are sure other people can come up with more reasons why this motor was bad.

Can Maxxforce Engines be Fixed?

Can-Maxxforce-Engines be-Fixed

According to the reports we have read, the answer would be a resounding no. Even though the company switched emission system technology, that only solved part of the problem.

Other parts broke down as well and with the dilution of the oil system with diesel fuel, the problems that arise from that source are many. The complicated and crowded engine was the biggest problem after the emission system.

With mechanics stating that fixing the engine would be a waste of money, you know that the motor was not worth its weight in iron or other metals used to make it. Scrapping it was their first answer to the question if it can be rebuilt.

Another problem was in the coolant design. Not that the fumes went into the cab but that when you went to refill it, the system had to be refilled from the bottom to avoid air pockets from forming in the system.

According to mechanics, there are just too many ways this engine could, and did, fail. 150,000 miles for a diesel engine is not good performance especially when the engine was built for the big rigs on the road. Those vehicles need performance and durability and the Maxxforce just didn’t have it.

Maxxforce Engine Problems

If you have read this far, you will have read quite a few of the problems that came with this engine. The emission system technology was just a part of it and =only the beginning. But another problem was management who did nothing to fix the emission system when it was brought in under warranty.

What the company did was simply replace one faulty system with another faulty one. That was not the Cummins’ SRC, it was Navistar’s own ERG system they put back into those motors.

Certain decisions by the people in charge were part of the problem and, unfortunately, specifics cannot be listed here. The indirect evidence of the financial losses, the lawsuit losses, the customer complaints, and so on show that there was a breakdown somewhere along the chain of command.

Mechanical problems come from bad business decisions and that is a major problem with this motor.

Some Final Words

For those RV owners with a Maxxforce 7 engine or another model, this may not be good news or new news. While there are some 7 owners that like the engine and have not experienced the troubles others have had, this was a great engine.

Sadly, the lemons outnumbered the good units and dealt a black eye to Navistar and International truck and Motor.

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