Every specific vehicle has its own problems. Perhaps half of the issues with the car during the ownership come from the engine bay or just the engine alone. For the used car buyers the choice of the engine may reflect what the car ownership experience will look like - whether it is going to be a problem-free joy or a nightmare to live with.

How not to choose a car with a bad engine?

Some engines may highly increase car maintenance bills. There also may be factory defects or mistakes that manufacturers were not aware of at the time of production and the owners may have not responded to factory recalls. Some engines, on the other hand, may go wrong after a certain mileage so make sure to check the CarVertical report for some possible rollbacks.

Audi/VW 1.8 T (EA113, EA827)

Looking for a car with decent four-cylinder petrol, you say? Well, you should skip the popular 1.8 turbo unit which was developed by Volkswagen-Audi Group (VAG) and used widely between 1997 and 2004.

1.8-litre turbo petrol four-cylinder unit offered great power for money. But some engineering mistakes paved the road for this unit to the list of worst engines. EA113 or EA827 codenamed engines can be found in cars starting from Skoda Octavia to more luxurious Audi A6 including the whole range of Volkswagens.

This particular engine tends to consume more oil than most of the similar engines. Furthermore, it is most known for the problem of oil sludge formation which is annoyingly expensive to repair. And yet, the 1.8 turbo unit usually gets its coil packs failing. So if you are willing to get a car that is easy to live with, you need to look for your beloved VAG car with another engine.

BMW 2.0 N47 (N47D20)

Noticeable rattle from diesel engines may be one of the significant signatures of such fuel type. However, some of them rattle more than the others, especially when it comes to the family of BMW N47 engines.

One of the main reasons why these motors are so loud and why they deserve their place on the list of worst engines is because of the usual timing chain wear and almost inevitable failure. N47 units offer great power delivery with only a fraction of fuel. But remember that saving money on fuel may turn out to steep repair bills since timing chain failure can cause collateral damage which will lead to only one pricey option - engine replacement.

That catastrophic failure is an odd thing to happen though since the engine control unit switches to limp mode when the timing chain gets worn out. The lesson is simple here: if you go for the BMW, make sure it is not powered by the infamous N47 four-cylinder diesel.

Mazda 1.3 Renesis (13B-MSP)

From the golden eighties to quite a relatively recent noughties Mazda was known for their extraordinary rotary engines. Full of character 1.3 Renesis units used in Mazda RX-8 may have delivered the power of a much bigger engine as well as unique sound and the ability to almost beyond. But there are more things required for the engine to be identified as a great one - sorry, rotary fans out there.

If there was a championship of the worst engines in the history of the automotive industry, perhaps this particular 1.3 Renesis motor would be a serious contender to the title. Having much less moving parts these motors should have been much more efficient. Mazda engineers often highlighted such things as less friction and more power. But in reality, rotaries were as thirsty both for fuel and oil as it was some sort of an old-school two-stroke engine.

Serious wear of apex seals usually caused major loss of compression which resulted in big power loss. Some sources say that the lifespan of this particular standard rotary engine is close to 60 000 kilometers, although it can be extended by the biggest fans of Mazda engineering. And yet, another tricky part is maintenance. It is quite a challenge to find yourself a workshop that will be happy to fix or service this charismatic yet troublesome motor.

VW 1.2 TSI (EA211)

There are many Volkswagen Group vehicles equipped with 1.2 TSI petrol engines, but it is highly recommended to avoid one. This little unit found its way to the list of worst engines mainly due to its timing chain issues.

It is known that 1.2 TSI are good up to a point of approximately 250 000 kilometers, but timing chain tensioner failure may occur at the early stage of 40 000 to 60 000 kilometers. Moreover, the test of time revealed another problem: timing chain can get stretched due to the construction of this particular engine and that is a source of great damage or steep repair bills. Luckily, Volkswagen has a wide range of engines to choose from.

Alfa Romeo 2.0 TwinSpark 16v

There are plenty of Alfa Romeo fans out there, but all of them should pay attention to the choice of the engines for their beloved present or future Romeos. Even if you found a great looking Alfa, make sure you check the condition of the TwinSpark 16 valve unit, especially if you go for the two-litre option.

With all the Italian engineering applied to this engine, it undoubtedly managed to squeeze onto the list of worst engines in the world. 2.0 TwinSpark engines are fragile and extremely dependable on the periods of an oil change as well as the quality of used oil.

True Alfa Romeo fans are aware that these full of character units are most alive when they are treated gently in cold conditions. Not being properly warmed up TwinSpark motors may break down upon an instant acceleration. So make sure that you are not in a hurry in the early morning - a dead engine is definitely not the thing you want for the start of your day. It is highly recommended to change the timing belt every 60 000 kilometers.

BMW N63 4.4 Biturbo (N63B44, until 2012)

Get a V8, they said. It will be fun, they said. Well, sometimes friends may not be aware of some issues of modern BMW V8s. The Achilles heel of the N63 V8 BMW unit is its weak cooling system.

The source of the problem is hidden in two turbochargers that sit right between the rows of cylinders. Even though this engineering solution granted a great packaging benefit for the BMW, the problem stays in bad heat management - both of the turbochargers produce excessive amounts of temperature which is not managed properly.

Combine this with quite a common failure of the water cooling system for the turbochargers and you get a pair of overheated cylinder heads. In that case, say goodbye to the variable valve control and camshafts or meet and greet your new neighbour - one big, fat repair bill. It is likely, it will stay there for a while.

On top of that N63 V8 units are also known for their problems with stretching timing chains and leaking injectors. The latter issue can cause severe damage to the cylinders since some drops of petrol can wash the oil from cylinder walls and a few cold-starts later the compression may be a thing of the past. It is known that BMW revised this engine in 2012 so most of these problems will likely be gone on cars assembled from 2013.

BMW / PSA 1.6 Prince (EP6)

The 1.6-litre PSA (Peugeot-Citroen) unit co-produced with BMW is a tricky one to maintain if it was assembled from 2006 to 2010. It was mostly used in various models of Peugeot, Citroen and Mini. These motors were often called VTi or THP.

The weak point of this compact four-cylinder is deep in the timing system. Usually, 1.6 Prince powered vehicles have their timing chains loose over the time which make the engine to be not as smooth as it was designed to be. Turbocharged versions suffer from the soot which leads to unpleasant jolting or noticeable loss of power.

Various sources indicate that it is handy to go for a newer engine if possible. Likely, many of these problems will not be present.

Fiat 1.3 MultiJet 1st generation (Z13D)

One of the worst modern Italian engines is a tiny 1.3-litre diesel unit from Fiat. The first generation of MultiJet is proven to be an oil-o-holic. Even though the manufacturer required to change the oil every 50 000 kilometers for these particular units, some of the heavier cars suffered even after the period was shortened to 30 000 kilometers.

Many users reported that this compact diesel engine consumes oil like there is no tomorrow. In addition to that, first-generation MultiJet units tend to break their timing chain and if that is not enough, then there is the fact that the coolant may easily find its way to cylinders.

In the cold period of the year after the engine is switched off the moisture is being condensed in the intake manifold and it eventually freezes. On the next start of the engine, the ice may get into the combustion chamber and cause some serious damage.

Isuzu 3.0 V6 D-MAX (P9X, Y30DT, Z30DT)

Regarding the somewhat expensive general maintenance of the 3.0 V6 Isuzu unit which is commonly used in various Renault models, the engine itself is a fast lane to financial bankruptcy.

One of the most common faults for these particular engines is poor cabling quality, unreliable Denso injectors and weakly engineered cooling system. The latter usually gets easily soiled and clogged which leads to big mechanical damage.

Even though these engines tend to show most problems in Saab and Renault applications, the same units in Opel cars are more reliable.

Opel 2.2 16v Ecotec (Z22)

The 2.2-litre four-cylinder Ecotec engine from Opel came in a few similar, but yet different forms. X22 units equipped with timing belts instead of chains are better to maintain, but you should avoid tricky Z22 units due to several reasons.

First and foremost, because of a problematic timing system. It is known that the tensioner of this particular engine may wear out too soon or simply even tear off. Things get even worse when you combine this with a faulty injection system.

The largest four-cylinder Ecotec engine paved its path to the list of the worst engines also with the help of fuel consumption. It is one thirsty unit - Opel buyers should take this as a bold notice, even though the name of the engine suggests it is supposed to be eco-friendly.

Renault 2.2 dCi (G8T, G9T)

The 2.2 Renault dCi unit offers a great balance of power and fuel economy although at a cost of reliability. One of the most common failures of this particular engine is its weak head gasket, which can cause the coolant to leak and eventually end up in the overheated engine.

Many people reported that fuel injectors are on the other side of fault-free and expensive to repair, too. Take that into account because injectors are sensitive to the quality of fuel.

Renault recommended changing the oil every 30 000 kilometers. However, there are proven records that used cars equipped with Renault 2.2 dCi units require far more attention than the manufacturer though many years ago. It is handy to change the oil as well as filters twice more often - every 15 000 kilometers, at least.

Saab 2.0 and 2.3 Turbo (B204, B234)

Living with a fast Saab may be fun, but some of the time the car will likely spend some time in the workshop. B204 or B234 units manufactured by Saab are known for some of their issues. And although it may not be the ultimately worse choice, owners of cars with these engines must be patient and open their wallets from time to time.

Due to the poor heat management, the front of the engine block may start overheating. To get things worse there is bad thermal insulation of the turbocharger which also makes things more complicated for the drivers. Too high levels of temperature cause crankshaft bearings to move out of their designated place and that causes great damage to the whole unit.

It is also extremely important to change the oil as often as possible since both 2.0 and 2.3 turbo engine designs cause oil sludge formation. People say that frequent oil change is not necessary - it is mandatory.

Skoda 1.2 HTP

Skoda designed 1.2 HTP engine may be useful for compact cars, although it is better to walk away from a car with this particular motor due to its addiction to technical problems.

The timing system is complicated in this case because weak hydraulic tensioner easily let the chain jump a tooth or a few even when the car is standing still on a sloping surface. There was simply too little tension and amongst the usual repairs, these engines are known as the ones which consume not only oil and fuel but also - wait for it - valves.

These cases could have been avoided by using the parking brake (handbrake) every single time the driver stopped the car, turned off the engine and left the car in gear. VW Group did try to recover from this, although it finally got away from the problem with the big redesign project and a highly refreshed Euro V standard version. New chain and tensioner were used to fix the problem. Although, these particular motors had problematic throttle butterflies as well as faulty EGR valves.

To spice up things, these tiny motors did not like being driven very hard. Upon such cases, valves were usually burnt.

Subaru 2.0D (EE20)

Subaru is one of few manufacturers that started producing diesel engines at a late point of their timeline. And regarding Subaru engineering, it certainly was a different approach, because it Japanese wanted to retain the traditional boxer engine layout.

The 2.0 D boxer diesel engine felt great, although a little bit rev-thirsty when compared to conventional diesel. Unfortunately, some of the first-generation of these particular motors were troublesome.

Injectors did not last long and this boxer diesel was known for its excessive oil soot formation. Owners of Subaru 2.0 diesel engines also reported that the particulate filter needs way more attention than normal.

Subaru did take care of their reputation and fixed all the issues upon warranty, but after it expired these motors were too expensive to live with. Due to boxer design, it is much more complicated to access some of the specific parts and yet if you really want that extraordinary diesel boxer unit, make sure you go for the Euro V standard one.

Toyota 2.2 D-CAT (2AD-FHV)

Toyota did not aim for the powerful average-sized diesel cars for a long time, but when they did the 2.2 D-CAT unit came out. With 177 HP and 400 Nm of torque, it offered the strongest punch in conventional sized Toyota cars range but big punch asked for some big issues.

It is likely that if you spot a D-CAT engine equipped car it will remind you of a factory chimney. These engines are known for their rather severe fumigation which often required to clean diesel particulate filter.

Another strange quirk of this particular engine is in the material which was used as a seal between the head and the block. Usually, it was complicated to remove it and in some cases, it was required to replace the head upon its removal since it had big marks of seal left.

D-CAT engines can be found in some Toyota models but the manufacturer also decided to put it under the bonnet of the only diesel-powered Lexus - the IS220. It could have been a great car, but bad engine reliability ruined it.

Volkswagen 2.0 PD TDI (EA 188 Piezo-PD)

Volkswagen’s 2.0 PD TDI 16v made its debut in the Passat B6 it did sell like hot pancakes. People had hoped it would replace the legendary 1.9 TDI unit and it was better in terms of refinement, but it had some serious drawbacks, too.

The 2.0 PD TDI engine with dual overhead camshafts had issues with the turbocharger, dual-mass flywheel and electronics. And that was just a start for the problems. Various sources say that the Bosch injection system is slightly less troublesome than the one made by Siemens.

However, the worst part of this particular engine is in it’s balancing shafts mechanism. It basically is the Achilles heel of the popular 2.0 TDI unit. Unlike the 1.9 PD TDI which had a single balancing shaft, the newer motor had two of them. With a relatively high gear ratio (twice faster than crankshaft rotation) it tends to mess up the life for one of the most important elements of any engine - a somewhat fragile oil pump. With a damaged oil supply 2.0 PD TDI motors will inevitably cause a breakdown and ask for a costly repair.

Volkswagen / Audi 2.5 TDI V6

An old unit that was commonly used widely in the second generation of Audi A6 or old Volkswagen Passats offered a great deal of power for its time. But it did have its weaknesses.

Due to the construction design of the cylinder head, the camshafts did suffer and worn-out too easily. One of the main reasons for this actual problem was way too optimistic oil change interval. If your car is equipped with this particular 2.5 TDI V6 unit, make sure you change the oil more regularly.

17 Worst engines in the world

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