5 Worst and 6 Best Engines of All Time

Five worst and six best reliable engines of all time. First top five worst engines ever made. Number five, Ford Triton 5.4. The power source under the hood of millions of Ford trucks, the Triton 5.4 liter V8 with overhead valves and three valves per cylinder sparks debate. It's widely praised for its robust performance and efficiency in the F-150 lineup. Ford enthusiasts boast about its longevity, often showcasing hundreds of thousands of trouble-free miles. However, not every owner shares such success stories. Ford 5.4 V8 engines are generally reliable, but some suffer from sludge buildup in oil passages, causing issues with cam phasers for variable valve timing. This can result in a ticking sound and trouble codes indicating cam and crank position mismatch, leading to performance issues or even engine failure if ignored. Phaser repair costs can reach $2,500. Pre-2003 engines had problems with spark plugs blowing out due to thread deficiency, while 2004 to 2008 models have a two-piece plug design prone to break during removal, leading to costly repairs. Despite many trouble-free trucks, concerns have deterred buyers, including noted mechanic Car Wizard, who advises against purchasing these engines due to frequent replacements. 4. Oldsmobile Diesel Diesel engines have long been known to be efficient consumers of fuel, but they present some trade-offs when used in place of gasoline. They are more expensive to build, produce more torque and less power, and produce an ever-present odor from their exhaust. Regardless, Oldsmobile engineers tried diesel as a way to introduce improved fuel efficiency into its line of large cars, wanting to copy the success of European brands selling diesel in the United States. Oldsmobile used its proven gasoline 350 V8 as a basis for the diesel. They created a reinforced block of a stronger alloy, meaning that it was not simply a gasoline engine with diesel heads slapped on it, and topped it off with new diesel heads. Unfortunately, the resulting engine fell short from the start. The power output was only 120 horsepower with 220 pound-feet of torque. Worse still, it was obnoxiously loud and played with an abundance of black smoke. In addition, the heads were secured by the same 10-bolt pattern as the gasoline version, which proved insufficient as the bolts began to stretch from the high compression required for diesel combustion. This resulted in blown head gaskets left and right, contributing to critical engine failures at Oldsmobile service departments everywhere. The diesel calamity led to a class-action lawsuit, followed by the creation of Lemon Laws. Diesel engines were only offered from 1978 to 1985, and the bad experience destroyed the ability to sell diesel cars in the country for decades. 3. The Toyota 3.0-Liter V6 Engine In particular, the 3VZ variant used in models like the Toyota 4Runner, HUCS, and T100 gained a notorious reputation for its persistent overheating issues and head gasket failures. These problems were often exacerbated by Toyota's decision to switch from asbestos-based gaskets to less heat-resistant materials, leading to frequent gasket leaks. Coolant would mix with the engine oil when the head gasket failed, causing the engine to overheat and suffer significant damage. Drivers often reported overheating at relatively low mileages, sometimes even before hitting 100,000 miles. Toyota attempted to address these issues with a silent recall, replacing faulty gaskets and offering extended warranties, but the damage to the engine's reputation was already done. Despite these flaws, the engine remained in production until it was gradually phased out in favor of more reliable designs. 2. GM 3.6 High Feature Engine The GM High Feature FE engine, jointly developed by Cadillac and Holden for the 2004 model year, has seen some extensive use across GM's brands in various configurations and displacements. Known for its reliability when operating smoothly, issues emerged in the 2.8 and 3.6-Liter variants during the 2007-2010 model years, affecting cars like the Buick Enclave, GMC Acadia, and Cadillac CTS. GM addressed these issues by the 2012 model year. The timing chain is critical for this engine, ensuring valves open correctly with a variable valve timing through hydraulic cam phasers driven by the chain. Maintenance is vital to keep the chain tight and well lubricated. When it stretches, symptoms like a check engine light and hood rattling, especially at idle, appear. Neglect can lead to engine misfires, metal shavings in oil, and potentially catastrophic failure, necessitating a costly new engine up to $7,000. Early detection reduces expenses, with timing chain replacement typically costing around $3,000. 1. Chrysler 2.7 V6 Found in a variety of Chrysler cars from 1998 to 2007 was the LH engine produced in 2.7-Liter and 3.2-Liter variants. They could be found in the Sebrings, Concords, and Intrepids of the day, providing decent power and efficiency, but not necessarily excelling at either. However, it did cause some owners grief when serious problems showed up after only several years on the market. A couple of years after purchase, customers started to complain about problems with the engine. Mechanical inspections revealed an alarming amount of sludge buildup By 2004, the Center for Auto Safety had received 92 complaints about the engines, while the NHTSA had more than 400. Engine repairs were costing car owners thousands of dollars, and the CAS called upon Daimler Chrysler to issue a voluntary recall on all 1998-2002 Chrysler vehicles with the 2.7-Liter V6. It turns out that a poorly designed water pump allowed coolant to leak into the crankcase, turning the oil into a gel and blocking oil passages. This could lead to complete engine failure. A class-action lawsuit was filed against Chrysler, with the company appointing a third party to administer claims. Although claimants complained that Chrysler made it extraordinarily hard to get approved for relief. Now, Top 6 Most Reliable Engines of All Time Number 6. 1965-1967 Ford R-Code 427 V8 Unlike many of the muscle car engines which were designed and engineered for street performance, the Ford EFI Big Block 427 cubic inch V8 was originally intended for the racetrack. The 427 made its debut as an engine option in the full-size 1963 Ford and Mercury models. This original 427 V8 was known as the Top Oiler 427. However, it was the introduction for the 1965 model year of the side oiler version of the 427 that has solidified this motor as one of the greatest performance engines of the muscle car era. Though there were a few different versions of this engine, it was the R-Code dual 4-barrel carburetor version available on a few 1965-1967 Ford and Mercury models that was the best performance engine Ford offered during the 1960s. As an example of its true potential, a 1967 Ford Fairlane equipped with a side oiler R-Code 427 V8 could run the quarter mile in 13.3 seconds. The R-Code had a 425 gross horsepower rating at 6,000 RPM, which was slightly underrated. Torque was factory rated at 480 pound-feet at 3,700 RPM. The 1965-1967 R-Code 427 had a mid-riser intake, a high-performance cam, high-performance heads, and a crazy 11.6-to-1 compression ratio. The 1965-1967 R-Code 427 was an honest-to-goodness racing motor rammed into a street car. This is why the Cobra Jet Cubic Inch V8, which was another high-performance iteration of Ford's FE Big Block, was more popular, though not as powerful as the R-Code 427. The Cobra Jet 428 and Super Cobra Jet 428 were high-strung and better suited for street use. Not to mention the 428 was less costly to produce. When the 1965-1967 Ford R-Code 427 ended production, it was the end of an era. Never again would Ford offer a genuine race car motor under the hood of a production car. Even the street version of Ford's mighty Boss 429 Cubic Inch V8 was tame by comparison. Number 5, the Chevrolet Small Block V8. Introduced in 1955, this engine family became the beating heart of American performance for decades. What made it special? Versatility and power in a compact package. The Small Block started at 4.3 liters but grew over time. The 5.7-liter version became legendary, powering everything from Corvettes to Camaros to everyday sedans and trucks. But it wasn't just about displacement. The Small Block was constantly evolving. Fuel injection, better materials, and advanced designs kept it relevant for nearly 50 years of production. Even after it was phased out of production vehicles, the Small Block lives on as a great engine for hot rodders and restorers. With over 100 million built, it's not just an engine. It's a piece of American history. Number 4, the BMW M50 engine. Introduced in 1990, marked a significant advancement in BMW's inline-six engine design. It was developed to replace the older M20 engine and was used in a range of BMW models throughout the 1990s. The M50 is known for its smooth operation and performance, contributing to BMW's reputation for engineering excellence. The M50 is a 2.0 to 2.5 liter inline-six engine, featuring an aluminum head and cast iron block. It utilizes a dual overhead camshaft design with 24 valves. The engine produces between 148 to 189 horsepower and 140 to 181 pound-feet of torque, depending on the displacement and model. It also introduced BMW's Vanos variable valve timing system in 1992, which enhanced performance and efficiency. The BMW M50 engine was used in several popular BMW models, including the E36 3 Series and the E34 5 Series. These cars were well regarded for their balance of performance, luxury, and reliability, making them favorites among driving enthusiasts and luxury car buyers. Praised for its mechanical robustness and ability to handle high mileage, the BMW M50 is a favorite among BMW enthusiasts. The engine is known for its ability to endure significant amounts of wear and tear while maintaining performance. Its straightforward design and reliable components have allowed many M50 engines to exceed 200,000 miles, making it a highly regarded engine in BMW's lineup. Number three, the AMC 4.0 liter inline-six. Introduced in 1986, this engine powered Jeeps for two decades, earning a reputation for unstoppable reliability. The 4.0 liter was an evolution of AMC's earlier inline-sixes, but it was a quantum leap forward. Fuel injection, better materials, and smart design made it both powerful and durable. This engine found a home in a variety of Jeep models, from the Cherokee to the Wrangler. It was known for its low-end torque, perfect for crawling over rocks or powering through mud. But what really set the 4.0 liter apart was its ability to take a beating and keep on ticking. These engines routinely surpassed 300,000 miles with basic maintenance. It's no wonder many consider it one of the best off-road engines ever made. Number two, Mercedes 300D turbo diesel. The Mercedes 300D diesel engine is one of the most reliable diesel engines in the world. Many of these engines are running around with 100, 200, and even 350,000 miles and are still purring like kittens. There are even videos of this engine running perfectly with over 200,000 miles and having just a few minor maintenance things done, like replacing the filters, rebuilding the injectors, and replacing all filters. Sure, none of the 300D cars with this engine would win a race as they were notoriously slow and loud. Turns out this car can do some burnouts with that diesel engine, and you'll hear many people saying the 300D was one of the best cars ever made. Number one, among unsung muscle car engines, the Chevrolet L79 327 cubic inch V8 has become the most well-known by muscle car fans and collectors in the last two decades. The L79 327 was produced from the 1965 model year through the 1968 model year. The L79 wasn't the most powerful small block Chevrolet V8 or even the most powerful 327 V8 ever produced. However, it was the 327 V8 which gave the true high performance power to the people. It powered many different Chevrolet models from 1965 through 1968. It was even available on the Corvette during this time period. It was never the Corvette's top engine option, but it did provide plenty of punch. The reason the L79 made this list was that Chevrolet didn't promote this engine. It treated it as just a very slight performance upgrade from its base 327 V8. As an example, bear in mind the hoopla may have been all about the 375 horsepower big block L78 396 cubic inch V8 equipped Chevrolet Chevelle SS during this era, but those cars were too pricey for most performance buyers. A buyer, however, could get a Chevelle with a 350 horsepower L79 327 for less than $3,000, which was a heck of a lot of performance for the money. For the last two model years of the L79, it was rated in some applications at 325 horsepower instead of 350 horsepower. The horsepower drop was just Chevrolet fudging the numbers for marketing reasons. The L79 still made 350 gross horsepower even when the factory rating was 325 gross horsepower. The L79 had an 11.0 to 1 compression ratio, a high-performance hydraulic camshaft, high compression pistons, and a 600 CFM Holley 4-barrel carburetor. For the 1968 model year, the Holley was replaced by a 750 CFM Rochester Quadrajet 4-barrel carburetor. The L79-equipped cars are capable of breaking into the 14 second range in the quarter mile, but that's not what makes the L79 so special. It's how easy and cheap it is to modify the L79 to break into the 13 second or 12 second quarter mile time range.