March 2021

Simultaneous hybridization As we have seen, turbo deployment has greatly increased in the last few years as VMs looked to increase power output from smaller engines, with one eye on emissions legislation. The growth in EVs would mean less turbos in passenger cars, but in other segments, turbo use may still continue to grow. “While the path to maximum electrification seems clear in the passenger car segment,” said a spokesman for BorgWarner, “requirements such as range, payload, charging infrastructure and costs make this path more difficult in the commercial vehicle sector. One development focus of manufacturers is therefore on increasing the efficiency of classic combustion engines with simultaneous hybridization. BorgWarner is also supporting manufacturers in their efforts from the turbocharging side. The company offers turbochargers with various technologies for commercial vehicle engines with displacements ranging from 1 to 18 liters and works to continuously optimize its advanced solutions. “BorgWarner has for example introduced commercial vehicle turbochargers with a 4th generation Variable Turbine Geometry (VTG), targeting 5 to 16-litre medium- duty and heavy-duty applications. Designed specifically to meet the challenges of modern commercial vehicle engines, the V4 VTG turbochargers feature improved peak power, reduced weight and case size, and increased thermal cycling resistance.” Options When it comes to souring turbos, there are a number of options. In addition to its thermal management side, Nissens Automotive has an aftermarket offering that includes turbochargers and related products. “The Nissens turbo offering falls within the company’s Engine Efficiency and Emissions product category,” said Marketing Manager Jan Zieleskiewicz, “and consists of more than 120 part numbers, catering for 1,500 OE references and providing coverage of in excess of 30% of the UK and Ireland car parc. “Turbo failures are often accompanied with, or caused by, problems with related components, which is why the Nissens programme also includes additional products such as turbo intercoolers, and oil feed pipes (OFP), which, as a best practice procedure, it recommends is replaced at the same time as the turbo. Nissens’ current OFP range caters for 99% of the company’s turbo programme, but is poised to increase over the next few months.” Turbo tips Jan continued: ”It is important for the technician undertaking the work to understand why the turbo has failed. Common causes that should always be considered in order to establish the correct diagnosis and address any underlying issues.” Oils and lubrication: “Has the failure occurred due to lack of lubrication? This can cause overheating in the turbo and lead the oil in the turbo to carbonise and the shaft to seize. This could occur because the OFP is blocked of restricted, due to exposure to excessive heat from a missing heat shield, for example. Alternatively, the engine oil could have become degraded because its scheduled replacement has been ignored or the oil filter defective. Also check the return pipe to ensure the oil can find its way back to the sump.” Foreign objects in the turbo: “Has something entered the turbo? A turbo acts rather like a vacuum cleaner sucking in a vast quantity of air, which it pulls through the air filter. Should air filter replacement be overlooked in a similar way to the oil filter example, foreign bodies can be sucked into the turbo and damage the veins on the compressor wheel, causing turbo failure.” Over-speeding: “Has the compressor wheel burst? Turbos are designed to run at incredibly high speeds, sometimes in excess of 250,000 RPM. However, if they exceed their normal operating parameters, due to over-speeding for example, the compressor wheel can literally break apart. Common causes include leaks in the air charge system or wastegate failure, which mean that the turbo can’t reach its designated boost pressure, so over-speeds to compensate, exploding in the process.” Over-pressure: “Is there an imbalance in the pressure between the air and exhaust side of the turbo? The thrust and journal bearing are designed to be subjected to a similar press, can lead to the compressor wheel touching the side of the housing, resulting in turbo failure. Causes can include excessive boost pressure because the factory settings have been changed due to engine tuning, for example. A malfunctioning blow-off valve or faulty MAP sensor could also trigger excessive pressure.” These issues and more are addressed through Nissens’ Robin Under The Hood series: www.nissens.com/robin Training For those looking for training, the Nissens Training Concept (NTC) is available. Jan commented: “This platform, featuring webinars and pre-recorded videos, is under constant development and designed to help technicians overcome the lack of live training meetings during the current pandemic. Users have unique access to the platform’s full library. This includes, among others, turbocharger self- learning modules and pre-recorded video webinars on important seasonal topics.” To access, visit: https://ntc.nissens.com/muc/ukaftermarket 34 AFTERMARKET MARCH 2021 Above: Turbo from Melett www.aftermarketonline.net TURBOS