Unveiling the success of the 0.9 TCe engine: A decade of budget-friendly power

The 0.9 TCe engine debuted in 2012 in the new Renault Clio IV model. It's commercially named TCe 90, after its 90 HP power output — the most sought-after variant. The engine also featured iterations with power outputs of 76 HP (TCe 75) and 109 HP (TCe 110), and since 2019, the output became 93 HP, not 90 HP.

The engine found its way into models such as Renault Captur and Twingo, Dacia Logan and Sandero, Nissan Micra, and Smart Fortwo and Forfour. Options were available with factory-installed LPG systems.

In the course of essentially a decade of continuance virtually unchanged, and with its newer 1.0 TCe successor being a mere evolution of the design, it is evidential of the success this unit had, at least for the manufacturer. For now, let's consider the older version with a displacement of 898 cc.

The engine, known as H4B, has an aluminium block, three cylinders, and a set of two camshafts in the head that operate a sum of 12 valves. Essentially, it's a truncated 1.2 TCe (H5F) engine. Although initially a Nissan design, it's generally accepted that the 0.9 TCe is a French engine given its collaborative creation between the two manufacturers and its primary popularity in French and Romanian cars. Furthermore, Renault branding, not Nissan, can be seen on many parts.

Even though it's usually seen as a downsized design, direct injection was not employed. There is, however, a turbocharger in combination with an exhaust manifold, aided by an intercooler. It incorporates variable valve timing phases — on the intake side. Other features include a start-stop system (also with an energy recovery function) and low-resistance materials (like graphite on pistons).

The engine is chain-driven, complemented with two slide valves and a tensioner. The second, smaller chain operates a variable capacity oil pump.

On the whole, the Japanese-French engine is a highly refined design that doesn't present significant issues. The fuel and ignition systems are virtually faultless, possibly due to it being an indirect injection. Moreover, the charging system, despite heavy usage, demonstrates impressive durability. The turbocharger benefits from dual cooling, with oil and liquid.

Obviously, the consistency of oil changes greatly impacts the longevity of this component – the more frequent, the better. Changing it every 10,000 kilometres, or yearly, is recommended, although the manufacturer suggests a lifespan of 30,000 kilometres or two years. Some cars are equipped with a system that reminds the driver about this.

Are there any recurring faults in this engine? Not many. One of them is the sealing of the thermostat casing, made of plastic like most components of this unit. These instances are quite infrequent, but they do reoccur. Hence, it's wise to check the coolant levels for any shortfall which might suggest this casing as the culprit.

Even less common is the cracking of the heat exchanger. The indication is the leakage of oil into the coolant. Most damage usually inflicts by mechanics, deficient in required skills, leading to easy damage of the numerous plastic engine parts. Conversely, parts are affordably priced and readily available as replacements.

If there is any oil discovered in the plastic intake manifold, the valve in the crankcase ventilation system should be observed. As it occasionally gets stuck and allows excessive fumes from the crankcase.

A frequent failure is the early stretching of the timing chain. It was designed by the manufacturer to last the entirety of the engine's lifecycle, therefore, any wear and tear in this area is taken as a malfunction. The most common cause is a blocked tensioner. These issues are random and independent of mileage. An distinctive rattling noise from the engine is the indicator. The timing replacement is a day's work for a mechanic with an approximate parts cost of £300. Once this area is fixed, it's wise to replace all components.

The 0.9 TCe engines were fitted with factory LPG systems in Renault and Dacia cars. This is a Landi Renzo system using high-quality components. It's specially tailored to this engine and, as per user experience, does not harm the valve seats.

However, it is important to note that the valves are adjusted using so-called push glasses, therefore, this could be necessary. The cost of the operation could exceed £200.

If you're contemplating buying a car with a 0.9 TCe engine, I've got a piece of advice — if anything will cause issues, it won't be the engine. It's one of the best developments in the Renault or Dacia lineup in the past decade.

In reality, a well-maintained engine not running on gas can easily withstand mileages around 250,000 - 300,000 kilometers. Even though there aren't many cars with higher mileages, the mere fact that not much needs to be done with the engine over these 300,000 kilometers makes it a prizewinner.

So, what's the secret of this engine? It is its simple design and the lightweight cars it serves. Unlike the 1.0 EcoBoost or even more so the 1.2 PureTech engine, which can be described as rivals, the 0.9 TCe units were never installed in compact cars, and the largest (and also the heaviest) model with this unit is Renault Captur.

The uncomplicated structure of the unit and its parts is another plus point. There are no complex exhaust purification systems, a lot of sensors, or intricate recirculation systems. Neither is there direct injection, which leads to several problems with the combustion process. Partly due to these reasons, this engine had to be discontinued in 2020 because it only meets the Euro 6 standard. The production of the fourth-generation Renault Clio and the popular Dacia Sandero, which had this engine installed on a large scale, also ended.

The heir, the 1.0 TCe engine, looks promising, but it adheres to stricter exhaust cleanliness conditions and made its way under the bonnet of the larger Dacia Duster. Will it be as successful as its predecessor? Let's allow a few more years for it to prove its worth, then we can assess.