10 Cars With the Most Horrible Engines of All Time

A set of camshafts out of a turbo diesel motor await their new donor motor | iStock

From econoboxes to luxury cars, there have been some serious stinkers over the years. Plagued with everything from recalls for door latches and exploding airbags, to transmissions locking up and engines exploding, it can feel like there are too many components on a car that can go wrong.

But of all the issues you can run into, having a doomed motor is perhaps one of the worst. It doesn’t matter if you have two cylinders or twelve, eventually a major component is going to grenade and leave you stranded. And while most cars will have 100,000 miles or more on their odometer before troubles start, certain engines suffer from birth defects right from the get-go.

Whether it’s due to poor engineering, materials, assembly techniques, or any combination of the three, crappy engines can quickly ruin the joy of automotive ownership while doubling as an albatross for the automaker. Which raises and important question: What are some of the worst engines ever made?

We’ve taken a look at the worst of the worst and come up with the biggest offenders. But instead of focusing on just classic engines or modern mistakes, we’ve created a collage that focuses on both. These engines didn’t need to be a recall disaster; some were prone to catastrophic failure from day one, while others just plain under-delivered.

10. Cadillac V8-6-4

In 1981, the engineers at Cadillac took a swing at making an engine with cylinder deactivating capabilities, much like what you see on the Caddies of today. Dubbed the V8-6-4 (i.e. Displacement On Demand), this engine had the ability to eliminate or activate two cylinders at a time as power requirements decreased or increased.

But the motor’s custom hydraulic lifters were controlled by failure-prone solenoids, and when they didn’t engage properly, lifters would collapse and valves couldn’t do their job. This made throttle hesitation a major issue for the V8-6-4, and when cylinders were deactivated enormous amounts of lag could be felt, especially in such a heavy chassis. This problem was so widespread that dealers were eventually told by GM to bypass the system, opting instead to simply trick the car into running on all eight cylinders. In today’s modern cars, cylinder deactivation works great. Back 36 years ago, the technology just wasn’t there yet.

9. Mitsubishi 3-cylinder

2015 Mitsubishi Mirage ES parked near a business.
2015 Mitsubishi Mirage ES | Mitsubishi

An abysmal 78 horsepower and 74 pound-feet of torque are all you’re going to get out of the Mitsubishi Mirage’s naturally aspirated 3-cylinder, and yes, that’s the latest GT model we’re talking about. Car and Driver might have summed this sad machine up best in December 2016, saying, “There is basically nothing to make a driver happy to be at the helm of a Mirage, nothing to love.”

The 1.2-liter sewing machine of an engine has extremely slow acceleration, and critics claim that highway passing with this car is both time consuming and dangerous. Buyers can also expect a great deal of racket coming from the motor itself, with one critic at Kelley Blue Book referring to it as, “more noise, vibration and harshness than you’ll get by putting bolts in a blender.”

8. Mopar 2.2-liter

Its marketing campaign may have made it look like a winner, but the Mopar 2.2 quickly became known as a rod-knocker  — and that was before Chrysler tossed a complicated turbocharger into the mix. Everything from the Dodge Daytona to minivans were receiving these powertrains in the 1980s, and almost all of them met the same fate in due time.

What’s interesting is that once upgraded with forged internals and aftermarket add-ons, the 2.2 turbo actually became a solid engine with surprising amounts of tuning potential. Unfortunately, it took the failures of thousands of the earlier powerplants to bring on these revisions.

7. Oldsmobile V8 Diesel

Often referred to as “the diesel debacle,” General Motors’ decision to put crude combustion technology in an array of Oldsmobiles proved to be a costly mistake. Instead of doing the right thing and utilizing a proven turbo-diesel powertrain or engineering a new one, the Detroit giant opted to “convert” gasoline engines in order to cut development costs. Buyers didn’t see just horrible performance numbers (120 horsepower and 220 pound-feet of torque), they also got one of the most problematic engines in history, which some still blame for ruining America’s interest in diesel cars.

While the diesel Olds’ reinforced block was bulletproof, inferior head bolts began sheering off of thousands of cars, and from there, things quickly got worse. Hydrolock from leaking head gaskets, not having a water separator in the fuel system, and a sloppy fuel pump timing chain could all cause catastrophic failures after just 30,000 miles. Eventually a class-action lawsuit was filed because the problems were so widespread. In fact, the Olds diesel became so infamous, it inspired legislators across the country to draft the nation’s first lemon laws.

6. Lexus 2.5 V6

View of the 2014 Lexus IS 250 V6 engine
2014 Lexus IS 250 V6 engine | Lexus

It may have offered a plethora of modern technologies and the initials “V” and “6,” but the lackluster motor from the previous generation IS 250 was anything but athletic. Power came from a pipsqueak of a 2.5-liter V6 that was both undersized and overly constricted by power-robbing emissions systems, leaving both critics and drivers underwhelmed.

On a good day the anemic V6 produced 204 horsepower and 185 pound-feet of torque, which is just barely more than what you’ll find in the old Honda Civic Si, which had two fewer cylinders. Back in 2013, Consumer Reports referred to the old Lexus 250 as “neither sporty nor luxurious,” and dinged it heavily for having acceleration that “lacks punch.” Critics were also extremely disappointed with observed overall fuel economy ratings, which compared with bigger V6’s hovered at a 20/23/27 average according to the EPA.

5. Chevy 2.2-liter Ecotec

Don’t worry folks, the new 2.2-liter Ecotec is perfectly fine, it’s the pre-2006 generation that you have to watch out for. The four-cylinder engine was infamous for refusing to provide power or reliability, instead insisting on things like fresh head gaskets and timing chain components.

Offered in everything from the Cavalier to the S-10 pickup, press reviews at the time urged buyers to stay away from attaching these engines due to poor performance. While a lack of power and durability were troublesome, corroding steel freeze plugs after 50,000 miles were one of the first-gen Ecotec’s major weaknesses. Editors at Hot Rod Network despised the problematic powerplant so much that they claim, “It’s no wonder GM used absolutely no engineering or design from this engine when developing the [new] Ecotec.”

4. The First Ford V8

The iconic Ford flathead was the first production V8 engine from The Blue Oval, and remained in production for over 20 years. It was an engine that was designed to move Americans into a new, faster era of transportation. But history could have turned out very differently…

According to reports and automotive historians, early versions of Ford’s mighty V8 was prone to all kinds of maladies. One anonymous expert tells the tale of piston rings that were not made of a properly hardened steel, which in turn caused the engine to burn oil. Due to cooling system design flaws, the rear cylinders always ran hotter than the front six, and the intake manifold never seemed to properly mix fuel with air. While one bank would run too rich, the other would run too lean, a quart of oil was typically burned ever 100 miles, and both ignition and water pump woes were commonplace.

3. Jaguar V12

Hemmings finds that heat tends to be the cause of most V12 Jaguar engine issues. Since ignition and fuel were in close proximity to one another within the piping hot valley of the “V,” both were prone to failure over time. And while this design was purposefully chosen to alleviate space constraints and worked well in the beginning, many gearheads still look at these engines as ticking time bombs.

Jaguar’s electrical system was also affected by the V12. The wiring closest to the engine would unravel and fry from the heat, causing electrical gremlins. And early versions of the engine also featured intakes that were covered in a snake farm of rubber hoses, which would crack and leak.

2. Subaru 2.0 and 2.5-liter (non-turbo)

The 2014 Forester 2.5i engine
2014 Forester 2.5i engine | Subaru

Both 2.0- and 2.5-liter versions of the naturally aspirated boxer engine from Subaru have been objects of scrutiny in recent years due to excessive oil consumption. Initially waved off as something that “Subaru engines do,” owners were told they need not worry if they added a quart of synthetic every few thousand miles. If the idea of a brand-new engine burning oil right off the lot concerns you, it should. It even led to the government stepping in.

The tipping point came in 2016, when Subaru finally admitted guilt and agreed to reimburse owners for repair costs and extend the length of their warranties. In a public statement, Subaru confessed that a defective piston ring could cause some 2011–2015 vehicles to excessively burn oil, prompting a lawsuit that alleged that Subaru knew about the problem but neglected to tell owners. Dealers had to to replace countless numbers of short blocks, a fact that lands this duo of boxer motors a number two spot on today’s list.

1. Yugo 55

In late 1983, the Yugo 55 came with a 1.1-liter carbureted engine that generated an abysmal 55 horsepower and had one of the worst reliability ratings in history. With a top speed of just 86 miles per hour (if you were daring and going downhill), the Serbian subcompact was the slowest car sold in the United States at the time, and was problematic to say the least.

One critical maintenance issue that was unique unto the Yugo 55 was the need for a replacement of the timing belt every 40,000 miles to reduce the risk of it snapping and destroying the engine. The need for premium gas was another strange requirement for this foul four-banger, and its finicky air pump-powered carburetor was both inefficient and detrimental to the brand’s longevity. In the spring of 1992, Yugo folded, after the EPA announced that every vehicle Yugo had sold in the United States failed to meet exhaust emissions.