DISAPPEARING CARS – RELIABILITY AND REPAIRABILITY
Globally the vehicle manufacturing industry has undergone a revolution – hybrids during the early part of this century, and then in the past decade, full electric drive. The upshot is while some markets are driven towards a political electric only Utopia (EU27, UK, US, Australia) others are dealing with far more practical matters such as where to get energy to power basic commodities.
Vehicle manufacturers – who primarily build vehicles for sale, with all other activities as an ‘add-on’ – had to create two, three or more versions of each model’s powertrain in recent times, compared to just one type at the start of the century. Add on top of this the campaigns by Euro NCAP, for example, to enhance safety beyond the legal minimum to meet type approval. Vehicle manufacturer product design and development has been at full stretch for a very long time. Mistakes have been made.
For most vehicle manufacturers the reality is they are building vehicles in much the same way as 25 years ago but with much more complex systems, so that a conventional internal combustion engine car with minimal SRS is on the same assembly line as a full-blown, fully-loaded, battery-electric vehicle. How has this affected the aftermarket?
We are going to look at this via the internal combustion engine. What follows does apply to almost every single system in the vehicle.
Trouble ahead
The major issue is the whole vehicle manufacturing ecology. It is configured to produce new vehicles mostly from new resources, yet in the market a vehicle can have a life of 14 years or more – this is the average age of vehicles in the US. Further, commercially, finance – the most profitable part of a vehicle manufacturer operation – is increasingly involved with second- or third time leases – that is to say, vehicles that come off lease after, say three years, go back into a lease again, and even again.
However, the ecology is configured around ‘lowest cost of ownership’ and so, lowest rate of warranty claim, in the first cycle of finance. Opel, for example, in pursuit of reduced cost of ownership in the mid-1990s, created a new 1.8 litre petrol engine design, validated throughout with semi-synthetic oil. After nearly four years, the production plant in Hungary stated, just as production was due to start, that since they had a tank filled with the cheapest possible mineral oil – used for the first fill – they could not ‘justify’ switching over to a more expensive oil. On the basis of one tank full of mineral oil in one factory, the 1.8 engine’s first sump full of oil was… nearly pure mineral.
The problem? Ahead of this debate, the servicing and warranty had been defined to show the first oil change – and subsequent oil changes – could be extended, so reducing cost of ownership. Using mineral oil instead of semi-synthetic oil undermined that. Consumers remained unaware, and the impact would be apparent five plus years into the vehicle life, unless the first oil change was done within 4 500 km and run thereafter on semi-synthetic oil.
Very, very few customers did that. The problem surfaced way after manufacturer warranty had expired, and all could point to ‘wear and tear’ if there was any damage. If the manufacturer now expects minimal warranty issues over three lease cycles on the very same vehicle, changing a key feature such as oil should be engineered – not just treated like bottled water.
But that’s not all. Due to the same ‘build and first use’ targets, the way vehicles are built is not always friendly to repairers. The South Korean and Japanese manufacturers get this, more so than many European or North American manufacturers. So, if we know no matter what the task the front bumper must come off, for example, it adds to the repair cost. It is fair to say quite a lot of newer vehicles are very sophisticated, regardless of purchase price, and what could – should be straight forward repairs are not due to lack of design for repairability.
Quite simply, repairing a vehicle requires removal of fewer, bigger sub-assemblies rather than the reverse of the manufacturing assembly process.
Now consider the warranty
A vehicle manufacturer is liable for mechanical warranty from new, for a limited period tied into time and distance, whichever is reached first. Subsequently, either as part of the finance package or independently, an owner may buy warranty extensions. The manufacturer warranty time is what is used by most insurers, since this is literally the claimed time to do almost any task.
Practically the manufacturer’s focus is on routine service, and that means trying to get customers to visit the retailer after sale whilst at the same time persuading them they don’t need to come as often. The problem, exemplified by engine oil, is this is a mixture of politics and engineering? In making smaller engines work harder, even when part of an ‘electrified’ powertrain, the oil works harder making thermal control even more critical. If the time between oil changes is extended then the cooling, filtration and oil quality need to be revised. Simply keeping everything the same and – say – doubling the service interval, will lead to longer term failure.
Crucially service outlets, even if they know this, are bound by commercial contracts. The consumer is not always given a choice.
A case study
Jaguar Land Rover decided to invest in a series of internal combustion engines under the ‘Ingenium’ brand, built at the new dedicated factory in the UK called i54 (a reference to the location, and ‘intelligent’). The first two versions – 2 litre petrol and 2 litre diesel four-cylinder engines – were fitted to Land Rover, Range Rover and Jaguar models from 2016 onwards.
Two further engines were added to the family – the 1.5 litre three-cylinder petrol unit and a 3 litre six-cylinder petrol as well as diesel unit, in 2019. The smaller engine is part of the PHEV package for Evoque and Discovery Sport. In July 2020 JLR celebrated the manufacture of the 1.5 millionth engine at i54.
The layout borrowed from a practice first enabled by BMW – develop a 0.5 litre piston/cylinder/combustion chamber/valve gear module, then configure, in this case, as a series of in-line engines. These could then be turbocharged, supercharged, have additional motors (MHEV, PHEV) to stretch the power outputs from modest levels to beyond 400 bhp. JLR threw everything then knew at this engine, from balancer shafts to built-up camshafts to ceramic ball bearings.
The task for Ingenium was significant. With the end of the Tata purchasing agreement with Ford and Peugeot SA (at the time) the transversely mounted engines were replaced with the first two 2-litre units. In addition, the newly introduced Discovery V and Jaguar ranges adopted the same engines mounted longitudinally.
JLR had one platform with three applications – Land Rover Discovery Sport, Range Rover Evoque and Jaguar E-Pace – which had a transversely mounted powertrain. Here the length of the engine with the transmission is critical to fit between the front chassis legs. All other JLR platforms and models have the powertrain mounted longitudinally, where powertrain bulk is less critical to fit between the front chassis legs.
From the start, to be competitive the Ingenium had an oil change interval of around 30 000 km. The engine output and compact packaging meant it was working hard – so if a customer skipped or ‘extended’ the oil change interval – there was almost no room for error – the intervals were not conservative.
The diesel uniquely drove the injection pump from the first stage, and on the second stage there was one camshaft phaser module – the petrol version had two camshaft phaser units. In all cases the chain was single row, again meaning there was a greater risk for stretch and so less room for error. Finally, should anything happen the diesel engine timing drive – sitting above the gearbox, behind the flywheel/flex plate – the engine has to come out of the vehicle.
Further, should the timing drive skip a tooth because the tensioner can’t take up the chain stretch any more, the valves will hit the piston crowns.
JLR in addition on the diesel fought one more issue – diesel particulate filter regeneration – which has now been revised. The system used to dump excess fuel into the engine as part of the regeneration cycle, so that the hot exhaust system would burn out trapped particulates. However, the system used to also do this at modest engine/road speeds, to the extent customers noticed the ‘oil level’ increased. Diesel did not burn at elevated temperature but instead washed past the piston rings and into the sump, degrading the hard-working oil. Hardly win-win.
The chain stretch issue has also claimed to have been solved with a component upgrade, although it is still a single row drive.
Lessons learnt
Right now, consumers have vehicles which can talk to the vehicle manufacturer about routine servicing or major faults, yet can still leave them stranded with a worthless vehicle. In the case study we can see a very sophisticated engine with no margin of error in a marketplace where it appears the support network as well as the customers remain splendidly unaware of the consequences of not servicing the vehicle on time, which is a widespread practice of new car owners.
The bigger picture is product complexity and often developing triple the number of new models with less than three times the head count, leads to things not quite working out. Even Toyota has six cases of type approval errors due to internal issues.
For the repairer this is double edged
On the one hand the job time for even simple repairs is likely to get longer until ‘design for repair’ comes back into fashion, while huge errors such as messing about with oil or timing drives, for example, could eliminate vehicles from use long before they would be scrapped.
Vehicle manufacturers are painfully aware of this, which is why Toyota, Renault Nissan, Stellantis and more are developing refurbishment processes to extend vehicle life. This is a step towards building vehicles for refurbishment/repair rather than the first finance/warranty cycle.
Story by Andrew Marsh
