Most Unreliable Engines That Fail By 100,000 Miles Within the Past 2 Years

The car repairs that get talked about the most involve the three most important systems of a vehicle: the engine, transmission, and electrical system.

How expensive? You may ask. Well, to give you an idea, for example, these repairs are among the top 10 most costly repairs you can expect in many models today:

• Engine Overhaul or Replacement: Cost: $3,000 to $7,000+
• Transmission Repair or Replacement: Cost: $1,800 to $5,000+
• Hybrid or Electric Battery Replacement: Cost: $2,000 to $8,000+
• Turbocharger Replacement: Cost: $2,000 to $6,000+
• Cylinder Head Gasket Replacement: Cost: $1,500 to $3,000+
• Suspension System Repairs (Air Suspension): Cost: $1,000 to $4,000+
• Timing Belt or Chain Replacement: Cost: $500 to $2,000+
• Fuel Injector Replacement: Cost: $1,000 to $2,500+
• Catalytic Converter Replacement: Cost: $900 to $2,500+
• Air Conditioning Compressor Replacement: Cost: $1,200 to $2,000+

Why Are Repairs So Expensive?

Multiple factors can make these repairs so expensive, such as complicated disassembly, using strictly OEM parts over used or aftermarket parts, and the garage's expertise and level of diagnostic tools.

This is especially true for modern Safety System sensors, which have to be recalibrated with an expensive scan tool when disconnected for disassembly.

In a sense, not only is your repair bill paying for parts and labor (including time), but you are also helping the garage recover the cost of diagnostic equipment needed so that you can get your car back as soon as possible.

As you can see from the list, an engine overhaul/rebuild or total engine replacement is about as bad as having to replace the battery on some EV models.

Related article: Why Car Maintenance and Repair is So High Today, Says This Mechanic

Avoiding the Reliably Unreliable

While ensuring that your car is properly maintained will go a long way toward avoiding many high-cost repairs, the fact of the matter is that some models are more prone to problems than others, regardless of the make. As we've recently learned this year, even Toyota has its occasional model problems.

To help you avoid the most unreliable cars categorized as those that might not reach at least 100,000 miles, here is a recent update from the Car Help Corner YouTube channel where the host alerts consumers to those makes and models identified by Car Help Canada. A non-profit organization that provides consumer advocacy and lobbying of the government on behalf of consumers.

You can follow along with the host in the video posted below or save some time by skipping to the summary of those models and the problems you want to avoid.

Worst Engines That Fail By 100,000 Miles || DO NOT BUY!

Worst Engines Video Summary

1. 3-Cylinder Ford EcoBoost Engines with Turbo―the 1L and 1.5L engines found in the Ford Escape and Bronco Sport models are the worst with engine issues. The 4-cylinder 2L and 2.3L models are a little better but still have their own separate engine issues with coolant leaks and intrusions, and head gasket problems. However, the 2.7L 6-cylinder EcoBoost engines used in trucks are much better, with the exception of the 3.5L EcoBoost trucks, which are known for timing chain issues and cam phasor failure.
2. GM 3.6L V6 and 2.4L 4-Cylinder Turbo Engines―Timing chain failure, excessive oil burning, water pump failure, and head gasket failure problems led the mechanics surveyed to adamantly advise consumers to avoid models with these engines at all costs.
3. Audi and Volkswagen with Their Turbocharged 4-Cylinder Engines―The earlier 2L engines, according to the mechanic's survey, have a high premature failure rate that occurs just after the warranty period ends. The newer Volkswagen models with the 1.4L and 1.5L turbocharged engines are also pegged as those to avoid due to a wide range of complaints from customers, including oil and coolant leaks, electronics, and ignition system failure, as well as turbocharger and timing chain failures that can destroy the engine before the vehicle reaches six figures. These are also expensive engines to have worked on.
4. BMW Twin-Turbo V8 Engines―Avoid the X5, X7, and the 7- and 8-series models carrying this engine, which are known for possessing hugely problematic engines with known oil consumption problems, carbon issues, turbocharger failure, leaking valve stem seals, timing chain failure, oil and coolant leak problems. Expect 4-figure repairs that never seem to get the repair problems right. However, the current generation inline six used by BMW since 2017 seems far more reliable and less problematic but still expensive to maintain and repair.
5. Mini Cooper with the 4-Cylinder Turbocharged Engine―Especially older models before 2015 known for being prone to oil consumption, carbon buildup, oil starvation, timing chain problems, turbo failure, water pump failure and many other problems that could lead to total engine failure. The newer mini models made after 2016 are much better, but the maintenance and repair costs have been high since BMW made them.
6. Fiat with the 1.4L 4-Cylinder Engine― Models with this engine are prone to oil consumption, timing belt failure, blown pistons and piston ring failure, damaged valves, turbo failure, and numerous other non-engine related problems.
7. Jaguar and Land Rover with Supercharged V6 and V8 Engines―Prone to several issues, including timing chain failure, oil and coolant leaks, gasket failures, oil consumption, supercharger problems, water pump failure, and several other smaller problems with expensive repair costs, “these engines are money pit cars” stated the mechanics in the survey.
8. Hyundai and Kia with 4-Cylinder Engines from 2011 to 2021― "The scale of engine failures with these vehicles is unfathomable, certainly unmatched by any manufacturer in modern history," states the host. Plagued by numerous recalls, both are prone to oil consumption problems, engine knocking, and check engine lights, which are often linked to rod or crank failure. On the newer engines, piston ring failure is often the case well before 100,000 miles.

A Special Note About the Vehicles Listed

While some consumers may take offense at some of the models on the list, it is important to note that the host points out that following the best maintenance and upkeep can delay having the problems stated with each make. The exception was Hyundai and Kia, where good maintenance alone was insufficient.

For additional related articles about avoiding those models with known problematic engines, here are three to help you look for a reliable vehicle during your next car shopping search:

• Most Unreliable Cars To Own Over 5-10 Years
• Least Reliable Cars That Won't Even Last 60,000 Miles
• Best High-Mileage Used Cars Recommended by Consumer Reports

Timothy Boyer is an automotive reporter based in Cincinnati who currently researches and works on restoring older vehicles with engine modifications for improved performance. He also reports on modern cars (including EVs) with a focus on DIY mechanics, buying and using tools, and other related topical automotive repair news. Follow Tim on Twitter at @TimBoyerWrites as well as on Facebook and his automotive blog "Zen and the Art of DIY Car Repair" for useful daily news and topics related to new and used cars and trucks.

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