Diesel engines are known for their reliability and power, which is why many people prefer them over their gasoline counterparts. But are all diesel drivetrains built to perfection? Certainly not!
Some of them are extremely unreliable and highly inefficient.
Here are 5 of the worst made by Ford.
6.0 Ford Turbo Diesel
Normally, a turbo-diesel engine is extremely powerful and capable of ripping apart the tarmac. When the engine capacity is 6.0-liters, the power multiplies even more so.
That’s what most of us expected when Ford released the 6.0 diesel in their F-series trucks and the company delivered. However, the 6L diesel engine fell short in an important department – maintenance.
This engine was known for its expensive repairs. It wasn’t user-friendly at all! You had to remove the cab just to put in new injectors, which racked up the repair bill.
As a result, all Ford vehicles having this motor fell in value, especially those produced during 2003 and 2007. No one wanted to deal with this capable yet difficult to maintain engine.
Moreover, the 6.0 L diesel drank fuel like there was no tomorrow. No one likes making frequent trips to the fuel station, and this engine made sure you were making too many. All the competitor engines did a better job in the power range and proved to be reliable and fuel-efficient.
Experts believe that the major reason behind the Ford engine’s failure was the abrupt announcement of modern emissions standards. The new EGR emission system required that all new and upcoming vehicles meet the rules and regulations.
Ford was forced to make changes, and that too in a small amount of time. That led to design flaws with the 6.0L Powerstroke engine. The head gasket is known to blow quite frequently, while the oil filters clog very easily, among other issues.
Once these issues are solved, the 6.0L turbo-diesel becomes a reliable companion. But who wants to spend money on making repairs on issues that should have been solved by the factory? Not too many people, I believe.
Read it: 10 Best BMW Diesel Engines (and Cars That Use Them)
Ford Lehman Diesel
Ford had a reputation for making diesel engines for heavy-duty applications. But little do people know they made some diesel engines for use in trawlers and sailboats. The company used the same engine in a few of its trucks and tractors owing to its sturdy design.
However, the Ford Lehman engine was nothing but a complete failure. It was unreliable and termed as a fuel-guzzling monster by some. If that wasn’t enough, the diesel motor did not produce much in terms of horsepower. It barely managed double figures, which proved to be very disappointing, considering it was a naturally-aspirated engine that consumed too much fuel.
The Lehman Diesel had engine technology that had long been forgotten. It was an engine that was living in the future while having all the specifications of the past.
Therefore, it had several reliability issues. You would have to learn how to change the lift pumps, injectors, and alternators regularly since this engine broke down too much.
Later on, Ford tweaked the design and added a turbocharger to the engine to help it produce extra power. That worked well, but despite its late bloom, the Ford Lehman engine went down in history as one of the worst naturally aspirated diesel engines.
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Ford Powerstroke 6.4 Turbo Diesel
Similar to the 6.0 Powerstroke, the 6.4 Powerstroke diesel has its own set of problems. That is mainly because the 6.4 bases itself on the 6.0’s design. In essence, they are the same, except for the fact that the engine capacity is different.
Ford made a lot of improvements to the new 6.4 after learning from the unreliability of the 6.0. As a result, the new motor managed 350 hp and 650-lb-ft of torque. However, Ford couldn’t solve the problems related to maintenance.
When it comes to repairs, you still need to disassemble parts of the engine and remove the cab to change the injectors. In other powertrains, that is not an issue. You only have to open up the hood and make the repairs.
Perhaps it would have been better if Ford solved this issue and made adjustments so that mechanics would have access to all the vital parts without removing any bulky part of the vehicle.
But Ford decided against that and went with fixing the reliability issues first. So, the 6.4 L turbo diesel isn’t such a bad motor, especially when you consider its performance output and fuel economy.
Yes, it suffers from maintenance, and that’s a pretty big issue if you have a heavy-duty truck from the Ford F-series. You need to have huge pockets to be able to handle a repair bill.
Also read: 10 Worst Diesel Engines that will Ruin Your Budget
Ford’s Diesel Vehicle Legacy to End?
It won’t be long before all diesel vehicles are pulled from the market. That’s because the EV revolution is in full swing, and with emissions regulations becoming stricter with each passing day, diesel vehicles will soon meet their end. Ford will sadly have to forfeit and move towards greener alternatives. They have already started to shift, and you can see that with their newest F-150 electric truck.
The electric truck is not only soundless and powerful, but it also passes the emissions test with flying colors. So, Ford’s diesel vehicle legacy might be coming to end, but it will soon be replaced, and we will see that in the form of new electric Ford trucks.
Read it: 10 Worst Diesel Engines that will Ruin Your Budget
What are the most Reliable Diesel Engines?
Ford doesn’t always do an awful job making diesel engines. Ford, combined with General Motors and Cummins makes some of the most reliable diesel engines in the world. Here are a few of the most reliable engines to come out of these brands.
LB7 6.6 L Duramax by GM
One of the best diesel engines in the modern world is the LB7 6.6 L Duramax made by General Motors. This powertrain is used by the GMC Sierra HD and the Chevrolet Silverado, among other vehicles. And the reason it is successful is because of its reliability and fuel-efficient nature. General Motors introduced the LB7 back in 2001, and even though that era was way before current emission regulations, the LB7 does pretty well, staying well under the limit.
6.7 L Powerstroke Diesel by Ford
I have mentioned quite a few unreliable Ford diesel engines above, and it is time for the brand to offer something as redemption. So, in comes Ford’s 6.7 L Powerstroke diesel powertrain – an engine that deserves countless appraise for its reliability, power delivery, and performance in challenging situations. The V8 motor is in its 3rd generation, and the way it’s performing in Ford’s Super Duty truck series, I don’t think that the 6.7 L will be replaced any time soon.
7.3 L Powerstroke by Navistar International
The 7.3 L diesel engine was manufactured by Navistar International – a well-known company that makes heavy-duty trucks and diesel engines. You will usually see this engine being used in Ford’s motor vehicles, especially under the Powerstroke name.
This engine is big & mean, and it excels at producing insane amounts of torque. The single turbocharger helps with power production, while the 7.3 L engine capacity certainly helps in that regard.
Also read: Why are Diesel Oil Changes so Expensive? (Explained)
Cummins 6.7 L Diesel Motor
Cummins is an ancient company that deals in the production and sale of engines. These guys put a lot of effort into the production of their products, which is why many automotive manufacturers reach out to them for help. One such manufacturer was Dodge, who used the Cummins motor for the RAM truck.
The 6.7 L engine made by Cummins has a V6 layout, which is a bit unusual for such a large motor, especially when a turbocharger is involved. Perhaps, the company was looking to reduce weight while producing immense power. Well, they achieved their goal, and you can see that by the power output of the Cummins engine.
This diesel motor produces 1,000 lb-ft of torque, which is enough to carry heavy loads and tow tons of weight at the back of your truck. Moreover, this engine has a diesel particulate system (DPF), which traps 90% of carbon output from the exhaust, cleans it through a process called regeneration, and allows the less harmful gases to leave the vehicle. Therefore, you pass the emissions test without an issue. So, there is no wonder why the Cummins 6.7 L can’t be one of the most reliable and successful diesel engines in the world right now.