When a reliable reputation meets engine pitfalls: The untold stories of Japanese car flops

Let's start with a brand perceived as one of the most reliable car manufacturers. One of Toyota's biggest flops was the D-4D diesels, which still divide drivers into satisfied ones and those who regret their choice. The history of the engine with this designation is long and complicated.

It all began in the 1990s when, in 1999, Toyota produced its popular diesel using Common Rail injection. Initially, the engine designated 1CD-FTV had a good reputation (e.g., in the Avensis I and RAV4 II). However, over time, typical faults associated with the Common Rail system began to surface, and improper repairs led to further issues. In retrospect, these were successful engines, although very costly to repair at the time. Today, there's no need to fear them.

The breakthrough came with the introduction of its successor, the 1AD-FTV, whose capacity increased from 2.0 to 2.2 litres. It was introduced in 2006 (e.g., in the Avensis II and RAV4 III) and failed. Not all units were problematic, of course, but many had serious issues with the head, block, DPF filter, and injection system.

After 2011, most of the issues were eliminated, and it is accepted that Toyotas, after the facelift or new generations introduced during this period, have defects-free engines. This includes models like the Auris II, the 2012 Avensis (facelift), and the fourth-generation RAV-4.

However, there's another trap here. In 2015, both the Avensis and RAV4 were refreshed, simultaneously discontinuing Toyota diesels due to the new Euro 6 emissions standard. Nonetheless, diesels were not completely withdrawn; a new engine named 2.0 D-4D with a capacity of 2.0 litres was introduced, which was a BMW design designated N47. This engine is known, among other things, for timing chain problems, whose replacement is expensive and problematic.

In my opinion, when buying a Toyota with a 2.0 D-4D Diesel, one should have the right approach to the topic. It's better to pay more for an older Avensis I or RAV-4 II than to buy the cheapest Avensis II or RAV-4 III. The best 2.0 diesels were in the pre-facelift Avensis III and RAV-4 IV but only until the facelift in 2015. BMW diesels aren't particularly bad, but they are more prone to faults and, due to the high emissions standards, less durable. So again, it's better to look for a well-maintained pre-facelift car than to purchase a cheap post-facelift car.

The petrol engine range also contains pitfalls. One of the biggest issues remains the ZZ-FE family known for its high oil consumption and several other shortcomings, making it Toyota's least successful petrol design after the year 2000.

ZZ engines were built in three capacity variants – 1.4 litre, 1.6 litre, and 1.8 litre – until 2008. They were installed, for example, under the bonnet of the Corolla IX, Avensis I and II, and RAV-4 II. In contrast, the successors had improved engines from the ZR family, also known as Valvematic, although these weren't used universally. Today, these are considered some of Toyota's best designs.

When searching for the mentioned models, you can fall into another trap. For instance, buying a RAV-4 II with a 2.0 litre engine can offer peace of mind because the engine belongs to the 1AZ-FE family, which has a very successful design.

In the Avensis II, the 2-litre unit also belongs to the 1AZ family but has an FSE appendix, indicating direct petrol injection. Although the engine is reasonably successful, parts are becoming increasingly hard to come by, and installing gas conversion is practically excluded. What can be successfully done in the RAV-4 and any Valvematic engine.

The VTEC abbreviation is highly regarded. Historically, Honda engines are considered nearly perfect and very durable. However, a significant flop occurred in 2001 with the K20 series engines, but this only emerged years later. The 2.0 i-VTEC unit was not made from the best materials, resulting in worn camshafts. Excessive oil consumption and piston swelling are also issues with this unit. However, it's important to note that this doesn't apply to every unit, and some people remain satisfied.

Thus, when relying on solid Japanese engineering when purchasing an Accord VII or Honda CR-V II, one may feel disappointed. A much better choice is a newer vehicle (Accord VIII and CR-V III) equipped with a 2.0 i-VTEC engine. It is a completely different design designated R20, praised for its absolute reliability and tremendous durability. Although in the first two years of production, it also had an oil consumption problem, the piston rings were subsequently improved.

Honda made some of the best diesels in the world. Initially, the reasonably simple 2.2 i-CTDi, followed by its successor 2.2 i-DTEC, which admittedly struggled with the DPF filter, but remains a very good design. Following this trend, many people trusted the 1.6 i-DTEC and unfortunately, that was a mistake.

The unit has been widely used since 2013 in Civics, but also under the bonnet of the large Honda CR-V. It is appreciated not only for its dynamics but also for its very low fuel consumption and smooth operation.

Over the years, it became apparent that it didn't last forever. Until the moment when the high emissions standard begins to affect it. After approximately 96,000 to 145,000 kilometres, injection system issues, exhaust gas cleaning system problems, and after higher mileage, axial clearance on the camshaft appear. Instances of cracking heads and blown gaskets have occurred. Allegedly, quality issues with this engine concern only units up to the 2016 model year.

Although unrelated to the theme of this article, it's worth mentioning two cases where one might unexpectedly end up with engines not fitting the brand.

The first case is the 2.0 DI-D diesel used in the Mitsubishi Lancer and Outlander II. You can recognise the engine by its 138 horsepower, and it's a Volkswagen 2.0 TDI PD design with a vulnerable head and defective lubrication system. The engine is generally decent but risky. Its advantage is good parts availability and cheaper repair options than the original Mitsubishi Diesel engine. However, it's worth being aware that this is not a Japanese engine.

The same is true for the 1.9 dCi (DDIS) unit used in the Suzuki Grand Vitara. It's also worth noting that Suzuki never produced its own diesels and, for example, the 1.9 DDiS engine in the Suzuki SX4 is a Fiat design, known as 1.9 JTD. In the case of the Grand Vitara, we are dealing with an engine too weak for the car, thus excessively burdened, which affects not only the bearings (for which this engine is known) but also the injection system.

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