Toyota's diesel dilemma: A history of hits and misses
In general, Japanese cars and engines are considered durable and reliable. With that assumption, you usually end up buying a good car. However, it's worth noting that Japanese designers have also made mistakes — and not small ones. Here are some examples of how easy it is to make a mistake and buy a lousy car when you intend to purchase a reliable one.
Let's start with a brand known for producing some of the most reliable cars. One of Toyota's biggest flops was the D-4D diesel engines, which still divide drivers into those who are satisfied and those who regret their choice. The history of these engines is long and complicated.
Diesel 2.0 D-4D – good, bad, good, bad
It all began in the '90s when, in 1999, Toyota launched its popular diesel using Common Rail injection. Initially, the engine designated as 1CD-FTV had a good reputation (e.g., in the Avensis I and RAV4 II), but over time, typical Common Rail system faults began to surface, and improper repairs led to further issues. In retrospect, they were successful engines, although very costly to repair back then. Today, there's no need to fear them.
The breakthrough came with the introduction of its successor designated 1AD-FTV, which increased in capacity from 121 to 122 cubic inches. Introduced in 2006 (e.g., in the Avensis II and RAV4 III), it turned out to be a failure. Not all units, of course, but many had serious problems with the head, block, DPF filter, and injection system.
By 2011, most issues were resolved, and it's generally accepted that Toyotas after this facelift or new generations introduced during this period have engines free of defects. This includes models like the Auris II, the 2012 Avensis (facelift), and the fourth-generation RAV-4.
However, there's another trap. In 2015, Toyota refreshed the Avensis and RAV4, simultaneously discontinuing Toyota diesels due to the new Euro 6 emissions standard. Diesels weren't completely abandoned; a new engine named 2.0 D-4D with a capacity of 122 cubic inches was introduced, designed by BMW and designated N47. This engine is known for timing chain problems, which are expensive and troublesome to repair.
In my opinion, when buying a Toyota with a 2.0 D-4D Diesel, approach with caution. 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 2015 facelift. BMW diesels aren't terrible, but they are more prone to faults and, due to high emissions standards, less durable. So again, it's preferable to find a good pre-facelift car rather than forcibly buying a cheap post-facelift model.
Gasoline engines are not much better
There are also pitfalls in the gasoline engine range. One of the biggest concerns the ZZ-FE family, known for its high oil consumption and several other shortcomings, making it Toyota's least successful gasoline design after 2000.
ZZ engines were built in three variants — 1.4 L, 1.6 L, and 1.8 L — until 2008. They were installed, among others, in the Corolla IX, Avensis I and II, and RAV-4 II. In contrast, successors had improved engines from the ZR family, also known as Valvematic, though not used everywhere. Today's versions are considered some of Toyota's best designs.
While looking for the mentioned models, you might fall into another trap. For instance, buying a RAV-4 II with a 2.0 engine can offer peace of mind because the engine belongs to the 1AZ-FE family, a very successful design.
In the Avensis II, the 2-liter unit also belongs to the 1AZ family but with an FSE appendix, indicating direct gasoline injection. Although fairly successful, parts are becoming harder to find, and installing gas fueling is practically impossible. This isn't the case for the RAV-4 and any Valvematic engine.
Good and bad Honda engines
The VTEC abbreviation is well-regarded. Historically, Honda engines are considered almost perfect and very durable. However, a significant flop occurred in 2001 with the K20 series engines, but this was only discovered years later. The 2.0 i-VTEC unit wasn't made from the best materials, leading to worn camshafts. Excessive oil consumption and piston swelling are also issues with this unit. However, not every unit has these problems, and some owners are satisfied.
Thus, when relying on solid Japanese mechanics, purchasing an Accord VII or Honda CR-V II might disappoint. A much better choice is a newer vehicle (Accord VIII and CR-V III) equipped with a 2.0 i-VTEC engine. It's a completely different design, designated R20, praised for its reliability and durability. Although it had an oil consumption problem during its first two years of production, improvements were made to the piston rings.
Three diesels, two excellent
Honda has created some of the world's best diesels. First, there's the reasonably simple 2.2 i-CTDi, followed by its successor, the 2.2 i-DTEC, which admittedly struggled with the DPF filter, but remains a very good design. Continuing this trend, many trusted the 1.6 i-DTEC, which unfortunately was a mistake.
This engine has been widely used since 2013 in Civics, and also in the large Honda CR-V. It is appreciated not only for its dynamics but also for its very low fuel consumption and high refinement.
Over the years, it became clear it doesn't last forever under the high emissions standards. After roughly 60,000 to 90,000 miles, injection system issues, exhaust gas cleaning system problems, and increased axial clearance on the camshaft appear. Cases of cracking heads and blown gaskets have occurred. Allegedly, quality issues with this engine concern only units up to the 2016 model year.
Two cuckoo's eggs
Although unrelated to the main theme, it's worth mentioning two situations where you 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. This engine, recognizable by its 138 horsepower, is a Volkswagen 2.0 TDI PD design with a vulnerable head and defective lubrication system. While decent, it is risky. Its advantage is good parts availability and cheaper repair options compared to the original Mitsubishi diesel engine. However, it's important to know this is not a Japanese engine.
The same goes 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 the 1.9 DDiS engine in the Suzuki SX4 is a Fiat design, known as 1.9 JTD. In the Grand Vitara, this engine is too weak for the car, leading to excessive strain, affecting not only the bearings (a known issue with this engine) but also the injection system.
