The used car market has a peculiar information asymmetry. The person selling the car usually knows more about it than the person buying it. But there is a layer above that: the professional dealer who has bought and sold enough of a particular model to know exactly where it will hurt them.
Car Dealer Magazine asked a number of working dealers which models they actively avoided. The same names kept coming up. Insurance data firm WarrantyWise provided the failure rates and average repair costs to put numbers against the warnings.
What follows is what they collectively know.
The Ford EcoBoost engine
Found in the Fiesta, Focus, B-Max and a significant portion of Ford's entire range, the EcoBoost is a compact turbocharged unit that delivers impressive power and fuel economy on paper. In the showroom it looks like a sensible choice. In the workshop it can be a different story.
The problem is the wet belt. Unlike a conventional timing belt, which runs dry, the EcoBoost's timing belt operates inside the engine oil. Over time that belt can begin to deteriorate. When it does, the degraded material circulates through the oil system and can cause catastrophic internal damage. The engine does not give much warning before it becomes very expensive.
WarrantyWise puts the average repair cost at £3,141. Lee Grant of the @CarUK channel on YouTube described it plainly: the wet belts are notorious for causing problems where the engine clogs up. He called it a "really poor engine."
The volume of Fords with EcoBoost engines on UK roads means the total number of failures is high even if the failure rate is around average for the segment.
The Mazda 2.2 diesel
This one surprised some buyers who associate Mazda with reliability. The brand has a strong reputation for durability, but the 2.2 litre diesel fitted to the CX-5, Mazda 6 and Mazda 3 is an exception its fans prefer not to discuss.
The failure catalogue is long and expensive: timing chains that stretch, injectors that leak, diesel particulate filters that fail prematurely, and exhaust gas recirculation systems that coke up badly. WarrantyWise describes this engine as more than twice as likely to fail compared to the average, with mean repair costs of £3,480. The firm's single most expensive claim on this engine reached £7,058.
James Harding of @ChopsGarage, who describes himself as a Mazda enthusiast, put it candidly: he loves Mazda as a rule and finds the brand generally bulletproof, but those 2.2 diesels have issues he has never seen matched by other engines when it comes to coking themselves up.
The PureTech petrol engine
The Stellantis group's PureTech engine appears in Peugeots, Citroëns and Vauxhalls, making it one of the most common powertrains on British roads. It also uses a wet belt.
The failure mode is similar to the Ford EcoBoost: the timing belt degrades inside the oil, the debris clogs the oil pickup, and the engine starves itself. WarrantyWise reports that PureTech engines are 31 percent more likely to fail than average, with mean repair costs of £2,152.
Joe Betty of the Shifting Metal channel, who runs a dealership alongside his media work, described the PureTech as having a "plethora of problems" including both the wet belt issue and a tendency to consume unusual amounts of oil. His assessment was that these engines are going to keep causing trouble for a long time.
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The Ford PowerShift gearbox
Not every problem is under the bonnet. The Ford PowerShift is a twin clutch automatic gearbox fitted to a generation of Fords and, less commonly, certain Volvo models. When it works, it is acceptable. When it fails, it fails expensively and completely.
The symptoms build progressively: jerky gear changes, hesitation, slipping, and eventually total breakdown. WarrantyWise's most expensive single claim on a Focus with a PowerShift gearbox came to £5,434, with an average repair bill of £2,351 across all claims.
Theo Cook of @TedTorques described the PowerShift as one of the worst gearboxes ever invented, "with no longevity, extremely expensive to repair, and causing a huge amount of problems." He was not speaking tentatively.
CVT gearboxes across multiple brands
Continuously variable transmissions are sold on their smoothness. They have no fixed gear ratios, just a continuous adjustment of drive ratio across a wide range. The result can be a pleasant, seamless driving experience. The failure experience is rather less pleasant.
CVTs across multiple manufacturers carry average repair costs of £2,924 according to WarrantyWise, though failure rates are roughly average. The practical problem for dealers is that when they do fail, the repair is complex and the replacement cost is high.
Jamie Caple of Car Quay and the @Carlateral YouTube channel is explicit about his approach: if he sees the letters CVT next to a vehicle description at auction, he does not bid. "We avoid them like the plague," he said.
The JLR Ingenium engine
This is the entry that attracts the most attention in dealer circles, because it appears in premium cars with premium price tags: Range Rovers, Discoverys and Jaguars bearing the 2.0-litre diesel Ingenium unit.
The core failure mode is a timing chain that stretches over time. A rattle on startup is the tell. If ignored, the chain can jump its guides and destroy the engine entirely. WarrantyWise's data is stark: Ingenium engines are 162 percent more likely to fail than the average vehicle on their books, with mean repair costs of £5,233. The firm's largest single Ingenium claim was £32,030 on a Range Rover Sport.
Umesh Samani, chairman of the Independent Motor Dealers Association, put the Ingenium diesel at the very top of his personal avoidance list. "They just fall to bits for no apparent reason," he said.
What to do with this information
None of these engines or gearboxes make every car they appear in unusable. Plenty of EcoBoost Fiestas, Mazda CX-5s and PureTech Peugeots run for years without incident. The question, as with all used car buying, is what happens when something does go wrong and whether you can absorb the bill.
The dealers who avoid these cars are not avoiding them because they never sell. They avoid them because when a £3,000 repair arrives on a car they paid £6,000 for, the margin disappears and the stress does not. That is a calculation a private buyer needs to make just as clearly.
If any of these drivetrains appear on the car you are considering, the advice that comes from every dealer in this conversation is the same: budget for the worst case repair before you commit to the purchase. The worst case is more common than the selling price suggests.
Sources:
- Car Dealer Magazine — Revealed: The cars even car dealers avoid buying
- WarrantyWise — Claims data on high-failure engines and gearboxes
- Car Dealer Magazine Podcast — dealer interviews on used car avoidance