23 Least Reliable Car Engines That Die Before 35k Miles (Junk)

Not all engines are built to last. Some are notorious for breaking down before they even hit 39,000 miles. Today, we're exposing the worst offenders, the 23 least reliable car engines that die before 35,000 miles, turning dream cars into pits. If you value long-term reliability, this is the list you can't afford to miss. Let's get into it. In the first spot, we have the BMW N63 V8 engine, 2008 to 2012. The BMW N63 V8 engine is all about power. It cranks out 408 horsepower and 440 foot-pounds of torque, and you'll find it in models like the BMW 550i, X5, X6, 750i, and 650i. It's fast, responsive, and impressive, but its reliability? Not so much. Early versions had a laundry list of problems. High oil consumption, turbo failures, and valve stem seal leaks were just the start. Over time, issues like coolant leaks, carbon buildup, timing chain wear, and injector failures became common. It's not uncommon for owners to spend between $5,000 and $10,000 annually on repairs and maintenance, especially as the vehicle ages. Then there's the turbocharger placement. It sits inside the engine's V, which makes it responsive and creates intense heat. That heat burns through oil quickly and can dry out gaskets. Number two is Isuzu 3.0 V6 D-MAX. The 3.0-liter V6 Isuzu engine, commonly used in various Renault models, is a fast lane to financial bankruptcy. This engine comes with serious flaws. The cabling is poor quality, leading to constant electrical problems. The Denso injectors are another weak spot, unreliable and costly to replace. Then there's the cooling system, which clogs easily. When that happens, the engine overheats, and you end up with major damage. Addressing cooling system blockages, including radiator replacement and system flushing, can range from $1,000 to $2,000. Despite performing well in Opel models, this engine often fails to reach 35,000 miles in Renault and Saab vehicles due to costly breakdowns. Next up at number three is Toyota 2.2 D-CAT. The Toyota 2.2 D-CAT engine, made between 2005 and 2015, was Toyota's bold attempt to introduce a powerful diesel option. With 177 horsepower and 295 foot-pounds of torque, it sounds impressive. But on the road, it becomes a problem for many owners. The most glaring issue is its severe fumigation problem. It produces so much smoke that the diesel particulate filter, or DPF, clogs up quickly. Replacing a clogged DPF can cost between $1,500 and $2,500, depending on parts and labor. Another problem comes from the head gasket design. Removing the cylinder head can leave deep seal marks, often requiring the whole head to be replaced, costing $2,000 to $4,000. This engine is used in several Toyota models, including the diesel Lexus IS220. Unfortunately, this engine often fails before 35,000 miles, with costly repairs making it unreliable for long-term ownership. Number 4 is the Subaru 2.0D 2008-2020. Subaru is one of the few manufacturers that started producing diesel engines late in their timeline. Instead of following the crowd, Subaru stuck with their signature Boxer engine layout. It gives the 2.0-liter diesel a unique feel and decent performance, but it's more rev-hungry than most diesels. That's where the problems start. The injectors don't last long, and the engine builds up too much oil soot. The diesel particulate filter also needs extra care, which makes maintenance a hassle. Replacing a single diesel fuel injector can cost anywhere from $300 to $1,100. Plus, dealing with soot issues, like cleaning or replacing the diesel particulate filter, can set you back another $100 to $3,000. While it had potential, the 2.0D engine doesn't hold up. Coming at number 5 is the Cadillac Northstar 5.8 engine. This engine from the 2000s is well-known for its head gasket issues and complicated design. The aluminum threads in the engine block are a big issue. They strip easily, leading to blown head gaskets. Even a little extra stress can cause major failures and leave you with expensive repair bills. Imagine this cost and effort involved. They cost between $2,400 and $4,500. Some mechanics may suggest replacing the entire engine, which can range from $6,000 to $7,000. The transverse position of the engine doesn't help either. There's very little room to work, so even simple jobs like replacing the starter or AC compressor become a real challenge. Number 6 is the Mazda 1.3 Renesis 2004-2012. The Mazda 1.3 Renesis engine, found in the RX-8, is a bold showcase of Mazda's rotary engine expertise. It packs impressive power for its size, matching much larger engines. Mazda praises its rotary design for having fewer moving parts, less friction, and more power. But in reality, the Renesis guzzles fuel and oil like an old two-stroke engine. Over time, its apex seals, a key part, will wear out. This time, you're already hit with a $1,500 to $2,000 bill for replacement or face a big power loss. Even with proper care, this engine doesn't make it past 39,000 miles. Rotary enthusiasts can sometimes push it further, but the costs are steep. Other than being unique and charismatic, the Renesis brings more trouble than it is worth. Number 7 is the BMW N47 diesel engine. The BMW N47 diesel engine, used in models from 2007 to 2012, delivers great performance and strong torque at low revs. On paper, it sounds like a solid engine. But in reality, it's known for one engine major flaw, timing chain failures. The timing chain is supposed to last the life of the engine. But with the N47, that's not the case. The chain is positioned at the back of the engine, making repairs complicated and expensive. When it fails, it can lead to catastrophic engine damage, often requiring a full rebuild costing upwards of $5,000. BMW did issue a recall and improved the design after 2013, but earlier models still carry the risk. This engine doesn't stop at one problem. Oil leaks and gasket failures are all too common, and fixing them? That'll set you back a hefty $1,000, because nothing about a BMW repair comes cheap. At number 8, we have the Audi 2.5L V6 TDI engine, 1997 to 2005. One major issue with the Audi 2.5L V6 TDI engine, used in older Audi and Volkswagen models, is the design of the cylinder head. This flaw causes the camshafts to wear out far too quickly. The problem is often linked to extended oil change intervals. You'll be putting additional strain on the engine components. To avoid these issues, owners need to perform oil changes more frequently, more often than what the manufacturer originally recommends. However, neglecting this maintenance can lead to significant damage and hefty repair bills. Replacing the camshaft costs between $2,000 and $3,000, with parts ranging from $45 to $800 and labor accounting for the remainder. A very decent performance of N47, but its reliability heavily depends on strict upkeep. Number 9 is the Toyota 4 GRFSE V6 engine. The Lexus IS 250's 4 GRFSE engine is a cautionary tale for drivers expecting bulletproof reliability. Known for Toyota's solid reputation, this engine, unfortunately, has some serious flaws. Here's why it's made the least reliable car engines list. Carbon buildup on the intake valves reduces power and throttle response. That's just the beginning. The weak timing chain tensioner causes clatter, clogged injectors disrupt idling, and early oil consumption wears out piston rings quickly. Worse still, some early models suffer cracked cylinder heads. Repair costs? Replacing piston rings runs $1,500 to $2,500 while fixing a cracked cylinder head can hit $1,200 to $4,800. Experts point to poor lubrication, low-quality fuel tolerance, and manufacturing faults. Plus, the high compression ratio causes excess heat, which only makes things worse. At number 10 is the Mini Prince engine. There have been quite a few reports of the Mini Cooper S with the N14 engine suffering a failure of the timing chain tensioner. When the chain stretches, you'll hear a loud rattle at idle, and the engine may run unevenly, making the ride far from smooth. The turbocharger wastegate system isn't much better. If it acts up, the engine starts running rough, and you'll likely see a warning light on the dashboard. Then there's the gearbox, which can develop issues due to a corroded selector shaft. Over time, this can seize up, and the car's gearshift left completely unresponsive. When that happens, mechanics won't just fix it, they'll replace the entire shifter assembly, hitting you with a $600 to $800 bill. It's a costly problem waiting to strike, so don't let it catch you off guard. Taking the 11th spot is Renault 2.2 DCI 1999 to 2009. This engine offers good power and fuel economy. Unfortunately, its reliability turns out to be a big disappointment. One of the biggest problems is a weak head gasket. This often causes coolant leaks, which could lead to overheating. Repairing this issue is labor-intensive and costly, with estimates ranging from $600 to over $2,000. The fuel injectors could be better. They are sensitive to fuel quality, prone to failure, and expensive to repair. Renault suggests changing the oil every 18,000 miles, but real-world experience shows that isn't enough. Owners decry they have to change the oil and filters every 9,000 miles to keep things running smoothly. At 35,000 miles, you're better off running a bike than relying on this engine. Number 12 We have the BMW S 65 V8 engine The BMW S 65 V8 engine, found in the E90 and E92 M3, is a performance icon. It's a 4.0-liter, naturally-aspirated V8 that revs to 8,250 RPM, a dream for enthusiasts. But here's the catch. While it's exciting to drive, it's just as likely to drain your wallet. BMW gave the S 65 incredibly tight clearances, which means those bearings wear out fast if you don't warm the oil properly or use the wrong type. Another headache is the throttle body actuator. BMW used plastic gears inside, which tend to fail. Fixing these issues can easily drain over $3,000 from your wallet. This is more stressful than fun. At number 13 is the Fiat 1.3 Multijet First Generation 2003-2009 The Fiat 1.3 Multijet engine has earned a notorious reputation. It is small in size, but big on problems. The most common complaint is its excessive oil consumption. Despite Fiat recommending oil changes every 30,000 miles, many owners found issues cropping up well before 20,000 miles. With a track record like this, it's no surprise the 1.3 Multijet often finds itself mentioned among the least reliable car engines. This engine doesn't just drink oil, it also comes with a host of mechanical issues. The timing chain is a known weak point and is prone to breaking. Coolant leaks into the cylinders are another frequent problem. Winter weather brings even more trouble. Moisture can condense in the intake manifold after the engine is turned off. Number 14 is the Skoda 1.2 HTP 2002-2007 Walk away from a car with this particular motor due to its technical problems. This engine has a notoriously weak timing system. Its hydraulic tensioner is so flimsy that the timing chain can jump a tooth or more even when the car is parked on a slope. Yes, you heard that right. Standing still doesn't mean trouble stays away. And that's not all. This engine doesn't just burn oil and fuel, it seems to have a taste for valves too. The VW group tried to fix things with a big redesign, adding stronger chains and tensioners in a Euro 5 version. But guess what? Problems didn't stop there. The throttle butterfly valves and EGR valves are also troublemakers. Push this engine too hard and you're looking at burnt valves. In the 15th spot is the Chevrolet 2.2L OHV Inline-4 engine. The 2.2L OHV engine in the Chevrolet Cavalier and Pontiac Sunfire has earned a reputation as a weak link. Problems show up early. Head gasket failures, oil leaks, and misfires are common headaches for owners. Yet, despite all this, the engine stayed in production for years, leaving many frustrated. Performance? It's not much better. Acceleration feels slow, and at high RPMs, the engine sounds wheezy and overworked. If you're thinking of upgrading it, think again. Mods are tough and expensive. And fuel efficiency? It's surprisingly low compared to similar engines. With so many drawbacks piling up, it's no surprise this engine often struggles to reach 39,000 miles before major issues arise. Coming at number 16 is the 1.5L or 2.0L EcoBoost. This engine is used in the Ford models. Unfortunately, it's plagued with problems that make it a questionable choice. Many Ford owners, especially Ford Bronco Sport, describe the engine as a whole can of worms. Critical parts have already failed for many and led to recalls. Rattling is a common complaint, often caused by low-grade fuel or oil leaks. These leaks are more than just a nuisance. They could lead to engine fires. Some owners have reported that their engines failed to start, even after Ford replaced the engine under warranty. Twice! The engine often shudders, especially at lower speeds, like 40 miles per hour or below. It struggles to keep up, and you'll feel it most when braking, where the RPMs can spike to 3,000 before the car stops. Dealerships may brush this off as characteristic of the vehicle, but the sporadic nature of these issues proves otherwise. These aren't quirks, they're flaws to qualify it among the least reliable car engines. Number 17 is the 5.3L Ecotec 3V used in the 2021 Chevy Suburban. This car might look like the perfect family SUV, but there's a serious problem under the hood. The lifters in the engine are a major design flaw, and they've caused headaches for thousands of owners. Here's the issue. Weak plastic keepers hold the lifters in place. When these keepers break, the lifters move out of position and damage the camshaft. As the camshaft gets chewed up, tiny metal pieces spread through the engine. These pieces clog the oil pump pickup screen and cut off the oil flow. Soon, you have engine failure. It doesn't stop there. Fixing this problem comes with a hefty Older GM engines like the SB350 were built to last, but the 5.3L Ecotec 3V8 feels far from durable. It's hard not to think GM is more focused on selling cars than building vehicles that stand the test of time. At number 18, we have the 3.6L Pentastar V. Six engine one major issue with the 3.6L Pentastar V4.6 engine is the Totally Integrated Power Module, or TIPM. Found in the 2018 Jeep Wrangler, the TIPM module is the brain behind nearly all electrical functions. It controls the fuel pumps, power windows, headlights, and even the throttle. But when the TIPM fails, and it often does, chaos follows. Your car might refuse to start, or even your radio could go silent. Fixing it isn't cheap either. Replacement plus repairs can set you back around $1,500. Another common complaint is the failure of the throttle position sensor. Once this happens, expect a poor throttle response and unpredictable performance. Wranglers also demand more maintenance than your average car. On top of engine and transmission oil changes, you must regularly service the transfer case and differentials. Skip these, and the repairs can add up fast. Coming at number 19 is the GM 2.4L Quad 4 engine. This engine was meant to be a game-changer for Pontiac Grand Am and Buick Skylark models. But when it comes to reliability, it falls short, especially for long-term ownership. One major problem is the oil change monitor system. It claims to track oil life accurately, but it often misses the mark. Owners who wait for the system to signal a change can end up with engine trouble. To keep things running smoothly, it's better to change the oil sooner, around 30% remaining, according to the system. Unfortunately, the GM 2.4L Quad 4 engine doesn't deliver much confidence when it comes to durability. It lacks the power and toughness of bigger engines, making you question, can it really go the distance? In the 20th spot, we find the Alfa Romeo 2.0 Twin Spark 16V. The Alfa Romeo 2.0 Twin Spark 16V engine, produced from 1995 to 2010, is as temperamental as it is iconic. Loved by enthusiasts for its character, it's also notorious for being fragile and requiring constant care. This engine thrives on perfect maintenance. High-quality oil and regular changes are non-negotiable. Neglect these, and you're likely to face major issues sooner than you think. Cold starts are another weak point. The Twin Spark needs to warm up gently. Push it too hard with quick acceleration in the morning, and you could be looking at a costly breakdown. For Alfa fans, the Twin Spark offers charm and performance, but it's not forgiving. If you rush it or skimp on care, it won't make it to 39,000 miles without trouble. Owning one requires patience and attention. Otherwise, that stylish Alfa could turn into a mechanical nightmare. Number 21 is the VW 1.2 TSI. The VW 1.2 TSI petrol engine, found in many Volkswagen Group vehicles, might seem like a good choice, until you take a closer look. One of its biggest flaws is the timing chain system. These engines are touted as reliable for the long haul, but the reality differs for many owners. Timing chain tensioner failures often strike early, anywhere between 20,000 and 40,000 miles, and it doesn't stop there. Over time, the timing chain itself is prone to stretching. This leads to significant engine damage and repair costs that can quickly spiral out of control. With such critical issues appearing so early, this engine feels like a gamble. The good news? Volkswagen offers plenty of other engines that are far more dependable. Coming at number 22, we have the Nissan 1.5-1.8 QG. Nissan's 1.5-liter and 1.8-liter QG engines, used from 1999 to 2006, are a surprising miss for Japanese engineering. While most Japanese engines are durable and use timing chains to cut maintenance, these models don't live up to the standard. The main problem? Excessive oil consumption. These engines burn oil fast, over one liter per 1,000 kilometers, sometimes even 1.5 liters. With an oil sump that holds less than three liters, it's only a matter of time before major engine failure strikes. The culprit is wear-prone piston rings, a flaw that makes these engines unreliable. Nissan will replace many under warranty, but beyond that, options are limited. Repairs are expensive and often not worth the trouble. Finally, number 23 is Saab 2.0 and 2.3 Turbo, 1990 to 2010. The Saab 2.0 and 2.3 Turbo engines are all about speed and excitement. But let's be honest, they spend too much time in the garage. One big problem is heat management. The front of the engine block tends to overheat, and the turbocharger's poor insulation makes things worse. All that heat can push the crankshaft bearings out of place, leading to serious engine damage. You also experience oil sludge issues. These engines are prone to buildup, so regular oil changes are a must. You cannot afford to skip the changes. You'll be looking at some expensive repairs. Yes, these engines offer a fun ride, but the maintenance demands are no joke. For many owners, the Saab 2.0 and 2.3 Turbo engines don't make it anywhere near 39,000 miles without major problems. Reliability can make or break a car, and these engines are proof of that. With fragile parts and costly failures, they're nothing short of nightmares. So, if you're in the market for a car, steer clear of these ticking time bombs, or risk breaking down well before 39,000 miles.