When shopping for a second-hand car, one of the biggest concerns for buyers is whether it might be riddled with problems and become a drain on their finances.
The reliability of any vehicle – new or old – ultimately comes down to how well it has been cared for throughout its life.
That’s why we always recommend avoiding cars with no service history, patchy maintenance paperwork, and any signs of modifications or prolonged abuse at the hands of former owners.
But there are some models that are notorious for having the same recurring problems that are almost always bank‑busting to fix.
Used car dealers have outlined six they won’t add to their stock for this reason alone. This is due to fears they might go wrong and cost an arm and a leg to put right, or that they’ll encounter disgruntled customers demanding to return vehicles.
Having spoken to a number of UK dealers, automotive trade title Car Dealer has listed which brands, engines and gearboxes might be worth steering clear of – and why.
And we can tell you which models these issues affect.
The 1.0-litre ‘wet belt’ EcoBoost engine was used across a number of Ford models in the 2010s, including the Focus
1. Ford models with ‘wet belt’ EcoBoost petrol engines
Ford debuted the 1.0-litre EcoBoost petrol engine in the early 2010s and it was seen as something of a game changer.
The three‑cylinder unit is compact, relatively lightweight, fuel‑efficient, low‑emitting and plenty powerful enough for daily driving. And Ford rated it so highly that it installed the engine in many best‑sellers, meaning there are tens of thousands on the road today.
But cars produced between 2011 and 2018 with the 1.0‑litre EcoBoost engine all share the same flawed feature – a ‘wet belt’. This is a rubber timing belt that’s submerged in the engine’s oil to stay lubricated, rather than operating dry like a conventional belt or chain.
It was designed to improve economy and reduce emissions. However, being submerged in oil means the belts degrade far quicker than a dry belt.
If scheduled oil changes aren’t adhered to and approved engine oil isn’t used, rubber particles from the belt can mix into the oil and clog or damage crucial components. This can be fatal for engines.
According to used car warranty provider Warrantywise, the average repair cost for a Ford EcoBoost engine is £3,100. While its failure rate is on par with other powertrains, the sheer popularity of the engine means problems are seen more frequently.
Speaking about the 1.0‑litre three‑cylinder EcoBoost, Lee Grant from dealer CarsUK told Car Dealer: ‘The wet belts are notorious for going wrong, causing problems when the engine clogs up, getting into the oil pump and causing catastrophic engine failure.
‘[Particles] can get into the vacuum pump and you can lose your brakes – which has happened. It’s just a really poor engine.’
In 2018, Ford discontinued the wet belt design and switched to a conventional chain drive for the EcoBoost engine.
Which cars are impacted?
Models fitted with the 1.0‑litre EcoBoost wet belt engine are typically those produced between 2010 and 2018, although some newer examples may also feature this powertrain.
Those impacted include the Fiesta, Focus, B‑Max, C‑Max, EcoSport and even the Mondeo.
A Ford UK spokesperson told us: ‘Ford is confident in the robustness and reliability of its EcoBoost engine technology when the stated guidelines for maintenance and service are followed.
‘Ford UK is happy to investigate service support and/or compensation measures for any customer who believes they have had an EcoBoost engine issue and is happy to review cases with a full service history for vehicles up to ten years old with less than 150,000 miles.
‘For any customers in the UK whose vehicle meets these parameters, you can speak to our customer relationship team. Contact details can be found on our website.’
Like Ford, a number of other brands (all now owned by Stellantis) used small PureTech engines with wet belts that succumb to the same problems. This includes the Peugeot 208 (pictured)
2. Peugeots, Citroens and Vauxhalls with PureTech engines
Ford isn’t alone when it comes to wet belt problems.
Stellantis – the parent company of major car brands including Citroen, Peugeot and Vauxhall – also sold 1.0‑ and 1.2‑litre petrol engines with wet belts during the same period.
Warrantywise told Car Dealer that the failure rate for the PureTech engine is 31 per cent higher than the average car, with repair costs typically coming in at just over £2,100.
Joe Betty, a former car dealer – who is now host of podcast Shifting Metal – says the 1.2‑litre PureTech engine has a ‘plethora of problems’.
He said: ‘The wet belt system either breaks or clogs the oil pick‑up and starves your engine of oil, completely ruining it. It also uses an absolute ton of oil – probably more oil than it’s going to use petrol.’
However, unlike Ford, Stellantis has acknowledged that the engine is flawed and taken responsibility by offering compensation to UK customers affected by mechanical issues linked to these engines.
Owners are eligible for compensation to cover costs related to excessive oil consumption and/or premature timing belt failure incurred between 1 January 2022 and 31 December 2024 for all cars fitted with the 1.0‑ and 1.2‑litre petrol PureTech engines, provided the engine has been maintained in accordance with the manufacturer’s schedule.
Stellantis has also extended the warranty on earlier generations of PureTech engines, covering 100 per cent of parts and labour costs for up to ten years or 112,000 miles, subject to certain conditions.
Which cars are impacted?
The PureTech engine has been used across various brands between 2012 and 2023.
Popular cars including the Citroen C1, C3, C4 and C4 Cactus; Peugeot 108, 208, 2008 and 308; and Vauxhall Corsa, Astra and Crossland were all available with wet belt PureTech engines.
Some Jeep and DS models are also affected.
Mazda’s 2.2-litre diesel engine introduced in the 2012 CX-5 (pictured) has a range of problems that has made dealers cautious about stocking them
3. Mazdas with 2.2‑litre diesel engines
Mazda is a Japanese brand with a reputation for near bulletproof reliability – but not when it comes to cars using one specific engine: the 2.2‑litre diesel.
Dealers say these engines are problematic and almost always expensive to put right.
Issues range from stretched timing chains and leaking injectors to failing diesel particulate filters (DPFs) and faulty exhaust gas recirculation (EGR) systems.
Warrantywise told Car Dealer the 2.2‑litre Mazda diesel is more than twice as likely to go wrong than average, with repair costs typically totalling around £3,500.
James Harding, who regularly posts about his business Chops Garage on YouTube, said: ‘It’s one engine I’ve repeatedly had issues with. As soon as I started buying them, everybody else started warning me off them – and now I know why.’
Which cars are impacted?
The Skyactiv‑D 2.2‑litre diesel debuted in the 2012 CX‑5 and was also used in the Mazda3 hatchback and Mazda6 saloon.
Mazda UK has been approached for comment.
The 2.0-litre diesel Ingenium engine sold in a variety of JLR models – including the Land Rover Discovery Sport (pictured) – have been found to suffer from stretched timing chains
4. Jaguar Land Rovers with Ingenium diesel engines
Launched in 2015, JLR’s Ingenium petrol and diesel engines – produced at its powertrain factory in Wolverhampton – were described by the British firm as ‘clean, refined and efficient’ and were built to maximise performance while reducing environmental impact and running costs.
However, the 2.0‑litre diesel has since become infamous for reliability issues.
Dealers say the timing chains are susceptible to stretching and – if they break – can destroy the engine.
Warrantywise told Car Dealer that Ingenium engines are 162 per cent more likely to fail than average, with repair bills exceeding £5,000.
Umesh Samani, owner of Specialist Cars Stoke and chairman of the Independent Motor Dealers Association, said the engines ‘just fall to bits for no apparent reason’.
Which cars are impacted?
The 2.0‑litre Ingenium diesel was used across much of the JLR line‑up from 2015 onwards.
This includes the Land Rover Discovery Sport and Defender; Range Rover Evoque, Velar and Sport; and Jaguar XE, XF, E‑Pace and F‑Pace.
A JLR UK spokesperson said: ‘Quality across the entire client ownership experience is a priority for JLR. Independent data shows our overall vehicle quality is at its strongest to date, and we continue to drive further improvements.
‘Our clients are fully supported with warranties and service plans that protect them throughout ownership. Any customers with concerns should contact their authorised retailer or repairer.’
CVT gearboxes are used in a variety of brands and models, including popular cars like the Honda Jazz. CarDealer says they are ‘extremely fragile’ and expensive to repair
5. Cars with CVT automatic gearboxes
For anyone who drives an automatic, it may come as a shock that a popular transmission is on the blacklist of many used car dealers.
The gearbox in question is the CVT – or Continuously Variable Transmission – which has been used in a wide variety of motors for decades.
Unlike a traditional automatic, a CVT doesn’t have fixed gear ratios. Instead, it uses a pulley and belt system to provide a seamless range of ratios. This allows the engine to operate at peak efficiency, with hard acceleration causing engine revs to rise and stay high to deliver power.
However, Car Dealer says these gearboxes are ‘extremely fragile’ and expensive to fix.
Warrantywise reports that the average repair cost for a CVT is £2,924.
Jamie Caple, owner of Derby‑based dealer Car Quay, said: ‘There’s one gearbox we actively avoid as a business, and that’s the CVT.
‘We avoid them like the plague. They’re problematic, difficult to fix and extremely expensive to replace.’
Which cars are impacted?
Many brands have used CVTs across multiple generations.
Japanese manufacturers are the most common users, including Toyota and Lexus, as well as Honda, Subaru and Nissan. Some Renault models also feature CVTs due to the firm’s partnership with Nissan.
Ford’s PowerShift automatic gearbox was fitted to models between 2010 and 2019. While clever, it is also very complex and expensive to fix when they go wrong
6. Fords with PowerShift automatic gearboxes
It’s not just Ford’s EcoBoost engine dealers are avoiding – the PowerShift automatic gearbox is also on the blacklist.
This transmission was widely sold between 2010 and 2019, overlapping with the era of wet belt EcoBoost engines.
The system is clever but complex: a dry dual‑clutch setup that effectively integrates two manual gearboxes in one unit. A computer anticipates gear changes, engaging one clutch while releasing the other to deliver smooth shifts – when it works.
But when problems arise, owners can experience jerky changes, loss of drive and total gearbox failure.
The complexity means repairs are costly, with average bills exceeding £2,350, according to Warrantywise.
Theo Cook, owner of Bowen’s Garage and YouTube channel TedTorques, said the PowerShift ‘has to be one of the worst gearboxes ever invented’.
He added: ‘It has no longevity, is extremely expensive to repair and causes endless problems. They shudder, vibrate and can completely lose drive. It’s a terrible gearbox nobody should stock.’
Which cars are impacted?
Ford used the PowerShift gearbox in Fiesta, Focus, Puma, EcoSport, Mondeo and Kuga models between 2010 and 2019, as well as the S‑Max and Galaxy MPVs.
Some Volvo models also used the PowerShift during Ford’s ownership of the brand, including the C30, S40, V40, V50, S60, V60, V70, S80 and XC70.