Volvo recently launched a new version of its 2,4-litre five-cylinder D5 turbodiesel engine, complete with upgraded air and exhaust gas exchange system, a larger, electronically-controlled turbocharger and an improved injection system.

Volvo recently launched a new version of its 2,4-litre five-cylinder D5 turbodiesel engine, complete with upgraded air and exhaust gas exchange system, a larger, electronically-controlled turbocharger and an improved injection system.


The new engine will initially be mated with a six-speed manual transmission and début in the S60 and XC90 model line-ups. The newcomers are expected at Volvo’s South African dealers in the fourth quarter of 2005. The introduction of these models with the six-speed Geartronic transmission will follow at a later date.


The next-generation D5 has a maximum power output of 136 kW (an increase of 16 kW over its predecessor) and peak torque has been increased by 18 per cent – from 340 to 400 N.m.


The new unit’s biggest strengths are considerably quicker responses at both high and low engine revolutions and high-speed cruising ability. The new-generation turbocharger has electronic control, a larger compressor wheel and its variable vanes have been cambered for a more efficient flow of gas at all settings.


The D5’s turbo centre housing is water-cooled, providing continued cooling of the turbo after the engine has been switched off. This is should be beneficial during short stops after high-speed driving, such as when refuelling on the highway.


As was previously the case, air swirls in the cylinders’ combustion chambers. The use of a new electronically-controlled multi-throttle system in the inlet ports allows infinitely variable regulation of the swirl level, and combustion can be adjusted extremely accurately according to the driving situation and the current engine speed and load, Volvo executives say.


“We have also made the combustion chambers larger, thereby lowering compression,” a spokesman said. ”By doing so, we have gained two things: higher performance and lower emissions.”


The injection system has been fitted with new injectors with seven finer nozzle openings as opposed to five in the previous engine. This results in a more finely atomized fuel mixture, and more efficient combustion. Injection takes place in three steps: pre-injection, primary injection, and post-injection. The last step is new and contributes not only to cleaner combustion but also to regeneration of the particulate filter.


A completely new, electronically-regulated quick glow system has been fitted to reduce glow times and make it easier to start the D5 engine in cold weather.

A new-generation engine management system includes electronic control of the throttle and the new, more powerful EGR (Exhaust Gas Recirculation) valve for more precise regulation of the air supply and recirculation of exhaust gases. A larger catalytic converter is now fitted close to the engine to promote faster warming and startup of the exhaust cleaning process.


All versions of the new diesel engine have a Coated Diesel Particulate Filter (CDPF), which removes soot particulates from the exhaust gases, with filtration efficiency above 95 per cent. Burning away soot particulates takes about 20 minutes and occurs at 500 to 1 000 km intervals, depending on driving conditions.


In addition to the technical changes, the diesel engines’ service interval has been extended from 20 00 till 30 000 km in the European market, but in South Africa the 20 000 km service interval stays in place pending an investigation into the improvement in diesel fuel quality in 2006.


S60 and XC90 D5 models sold in South Africa are also subject to a 10 000 km oil and oil filter change service. All service and standard maintenance costs are covered by Volvo Car SA’s 5 year/100 000 km Volvo Plan, however.


Lastly, Volvo’s All-Wheel Drive system (AWD) with Instant Traction, which was introduced on the V8-powered Volvo XC90, can now be combined with the D5. The system will also become available for the XC70 AWD, the Swedish manufacturer said.


“The D5 engine with a six-speed gearbox and All-Wheel Drive is a nearly unbeatable combination,” a Volvo spokesman said. “It offers enormous driving pleasure while also providing power and low-rpm capacity for the most demanding uses.”

Original article from Car