Top three most common car faults and average repair costs revealed

Claims for alternators, batteries, coil springs and water pumps were the most common, according to new research from the Warranty Solutions Group (WSG).

It analysed 44 manufacturers, which ranged from the biggest volume brands in the UK to prestige and niche marques, to identify the top three most common faults and average repair costs based on its 2022/2023 warranty claims data on vehicles aged 3-8 years old.

Alternators, batteries, coil springs and water pumps were the most common failures, making up 12.12%, 6.06%, 6.06% and 3.79% of the top faults respectively.

The most common causes of alternator failures were use-related wear and stop/start technology adding strain to electrical systems.

Alternators also made up 21% of all electrical claims paid by WSG last year.

The prime reason for battery claims was the increased demand being placed on electrical systems such as infotainment, advanced safety features and climate control.

Damage caused by potholes and general age-related wear were the main causes of coil spring claims, while internal bearing failure and seals and gasket failures were the main causes of water pump claims.

WSG says that the shortage of aftermarket parts was the main cause of many of the most expensive repairs seen across the volume manufacturers.

Amongst these were Land Rover diesel particulate filters (averaging repair costs of £1,485.26), Mazda turbochargers (£705.60) and Subaru catalytic converters and gearbox valve bodies (£2,358.20 and £1,671.52), all of which require the fitment of new OEM parts.

There were also a number of repairs in the top faults that can only be carried out by main dealers or specialists, subsequently increasing labour costs.

Two examples of this were Mitsubishi gearbox repairs (£1,129.29) and Suzuki media head replacements (£1,692.43).

The high average claim cost of BMW timing chains (£1,236.92) was due to the lengthy stripping process required in order to replace these parts across many of the BMW models, resulting in large labour bills.

The analysis also revealed that Volvo owners typically prefer to use a main dealer or specialist for major repairs - a factor that has resulted in increased labour costs for EGR valve replacements, with repairs averaging £715.30.

Prestige and niche manufacturer repairs

Average repair costs across the prestige marques were naturally higher due to requiring main dealer or specialist labour rates and OEM parts.

McLaren had the three most expensive claims out of all of the prestige manufacturers, with the most common faults being dual linear solenoids (£9,027.00), camshaft phasers (£6,087.00) and gearbox ECUs (£3,950).

Ferrari was the second most expensive with gearbox repairs (£4,166.67) and pipes (£3,633.47), followed by Bentley with air conditioning compressors (£2,799.99) and steering columns (£1,695.99).

Limited availability of aftermarket parts was the main factor for the more expensive repairs across the niche brands.

Amongst these were Chevrolet automatic transmissions (£3,600), DPFs (£1,766.04) and dual mass flywheels (£833.33), Caterham differentials (£3,531.10), Maserati catalytic converters (£2,435.77) and transfer boxes (£1,962.65), Chrysler gearbox repairs (£1,625.00) and Alfa Romeo dual mass flywheels (£963.33).

15 most reliable volume manufacturers

WSG analysed the 15 most reliable volume manufacturers based on at least 500 warranty sales per brand during 2023.

Honda took the top spot as the most reliable with a claim rate of just 4.18% and average claim of £364.89.

While Honda has experienced a similar claim rate for the last two years, there has been a significant drop in the overall costs of parts, due to the increased availability of aftermarket components. 

Battery failures were the most common issue across Honda models, making up 20% of all claims with an average replacement cost of £220.50.

Toyota was the second most reliable with a claim rate of 4.44%, followed by Hyundai (8.36%) in third position.

Starter motors and solenoids were the most common issues for Toyota (5.66%) with an average claim of £324.44, whilst ignition coils were the most common fault for Hyundai models (7.45%) averaging £119.13.

Volkswagen and Fiat were the bottom two out of the 15 manufacturers.

The most common claims for Fiat were alternators, clutch master cylinders and ignition coils, with average repair costs of £245.53, £307.78 and £195.78. 

Out of all 44 manufactures, Jaguar saw the biggest increase in average claim cost (45.65%) compared to 2022, rising to £668.06.

The main driver for this change was the availability issues with aftermarket parts.  There has also been an increase in Jaguar owners using specialists or franchise dealers for repairs, incurring increased labour costs.

Martin Binnee, operations director of WSG, said: “The build quality has improved significantly across all car manufacturers over the last few years and generally vehicles have become more reliable. 

“However, rapidly advancing electronics have increased the likelihood of more complicated and expensive faults.

“One knock-on effect of this is being seen in the SMR sector, where smaller independent garages are finding it increasingly difficult to compete with franchised dealers and specialists due to equipment and expertise constraints.

“Our extensive analysis of live, empirical data has enabled us to showcase the faults across over 40 manufacturers and models in the UK and highlights the most and least dependable models.”

The Honda Jazz, Toyota Yaris and Toyota Aygo were the three most reliable.

BMW had the largest number of models in the line-up (the X3, X1, 2 Series and 3 Series), but the average claim cost for the 2 Series was the highest out of all 20 models.

Automatic transmission, timing chains and torque converters were amongst the highest 2 Series claims, averaging £2,135.42, £2,500 and £2,500 respectively.

Steph Newbery, WSG’s group marketing director, said: “The Honda Jazz takes the pole position as the most reliable used car – an outstanding achievement for Honda, which was also the most reliable manufacturer in our analysis.

“With an enviable reputation for reliability and longevity, Honda has low claim rates and competitive parts prices, making it a great choice for the budget-conscious buyer.”

10 most popular models sold across the WSG dealer network during 2023

The Ford Fiesta was the most popular used car in the UK during 2023, according to SMMT data, and the most popular across the WSG dealer network, making up 3.76% of all car warranty sales during the same period. 

Fiesta claims accounted for 2% of WSG’s car warranty claims in 2023, and 16.5% of the total Ford claims. The average claim was £360.07, while the three most common issues were alternators, coil springs and timing belts.

The Vauxhall Corsa was the second most popular model sold through the WSG network.  While the claim rate for all car warranty claims was lower at 3.17%, the Corsa made up almost a quarter of all Vauxhall claims (24.74%). 

The third most popular was the VW Golf, which accounted for 2.64% of all car warranty claims.  However, Golf claims made up the largest percentage of manufacturer claims in the top three, accounting for almost a third (31.47%) of all claims across the Volkswagen car range.