Fault File
All models / All cars / Coupés, convertibles & GT / BMW 8 Series

BMW 8 Series

All generations and engines together · 5,627 MOT tests in the 2025 data · typical mileage at age 7: 59k

Typical mileage at age 7
59k miles
Check the mileage view below; low-mileage models can look better by age than they are.

How this model wears

BMW 8 SeriesClass average, all tracked models

Known issues

Measured

Computed from DVSA MOT results, all of Great Britain, 2025. Nothing here is opinion.

What testers flag

Share of tests where each item was recorded. The dark tick is the class average across all tracked models; bars are scaled within each group.

Faults with the car itself

The rows that judge the model rather than its keeper. 4,836 tests in this band.

A transmission shaft flexible coupling excessively deteriorated
Advisory
1.8%class 0.0%
Any fracture or welding defect on a wheel
Fail
0.8%class 0.1%
A wheel badly distorted or wear between wheel and hub at spigot mounting
Advisory
0.8%class 0.4%
Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users
Advisory
0.4%class 1.2%
A direction indicator lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning
Fail
0.3%class 0.1%
A transmission shaft flexible coupling excessively deteriorated
Fail
0.3%class 0.0%
Excessive fluctuation in brake effort through each wheel revolution.
Advisory
0.2%class 0.3%

Wear, upkeep and luck

Tyres, pads and stone chips say more about how the car was driven and maintained than about how it was built.

Tyre tread depth not in accordance with the requirements
Advisory
18.9%class 18.8%
A tyre seriously damaged
Advisory
10.7%class 13.1%
A tyre seriously damaged
Fail
7.2%class 2.3%
A tyre cords visible or damaged
Fail
4.6%class 1.3%
A brake lining or pad worn below 1.5mm
Advisory
3.1%class 7.2%
Nail in tyre
Advisory
2.3%class 1.7%
Tyre tread depth not in accordance with the requirements
Fail
1.3%class 2.3%
Brake disc or drum excessively weakened, insecure or fractured
Advisory
1.3%class 7.0%

Unconfirmed issues

Reported

Owner folklore from forums and the motoring press. Most of it never shows up in an MOT, which is why this section exists at all.

Sill and jacking point corrosion (E31)

Partly in the MOT data

On the original 1990-1999 E31 coupe, rust eats into the sills from the inside out, starting around the jacking pad sockets and sill extensions. Owners and specialists report jacking a car at the factory point and finding the jack rising while the sill crumbles and the car stays put, because the metal has gone from the inside. This lines up with corrosion being the measured MOT fault for this segment: the underbody rot is real, it just tends to hide behind trim until it is structural.

Mainly cars over 20 years old · sources: ShiftBMW E31 corrosion guide, Bimmerforums, Honest John classics review

N63 V8 oil consumption and timing chain rattle

Confirmed pattern

The 4.4-litre twin-turbo V8 in the M850i and earlier 850i/M8 models is known for burning oil through worn valve stem seals, showing up as blue smoke on a cold start once the car gets into six figures on the clock. The same engine family can develop timing chain and guide wear that rattles on startup before the oil pressure builds. Valve stem seal work runs to several thousand pounds, and a chain and guide job on the low side of that; the N63 family's oil-burning issue was serious enough that BMW extended warranty cover on earlier versions of the engine in the US.

Reported from 100k+ miles · sources: What Breaks BMW 8er guide, Engine Patrol, BimmerPost owner threads

Starter motor overheating and fire risk (recall)

Confirmed pattern

BMW recalled 8 Series cars built between March 2018 and February 2025, alongside several other models, over a starter motor whose electrical contacts can overheat on repeated starting attempts, in rare cases igniting nearby components. A buyer should check the recall has actually been carried out, since a wider fix (a redesigned starter) followed an earlier, less complete repair campaign. The fix is free at a dealer once it's done properly.

Applies across the model's production run · sources: NHTSA/KBA recall notices via car-recalls.eu, Autoevolution

V-valley coolant leaks on the V8

Emerging

On M850i and other N63-engined 8 Series cars, coolant pipework buried in the valley between the cylinder banks can weep or fail, a spot that's fiddly and labour-intensive to get at because the intake manifold has to come off first. Owners usually notice a slow coolant level drop or a sweet smell before it turns into a proper leak. It's flagged as a known weak point on modern BMW V8s generally rather than an 8 Series-specific fault, and there's no factory recall for it.

Reported from 60-100k miles · sources: Honest John buying guide notes, owner forum reports

B58/B57 oil filter housing and EGR/AdBlue faults

6-cylinder petrol and diesel only

On the six-cylinder 840i (B58 petrol) and 840d (B57 diesel), the plastic oil filter housing can crack and let coolant and oil mix, and the EGR cooler and AdBlue/SCR system on the diesel are reported to fail from around 70-80k miles with white smoke, a check engine light or an AdBlue fault code. Repairs range from a few hundred pounds for a housing or sensor up to several thousand if the engine's been running mixed fluids for a while. Doesn't affect the V8 or V12 cars.

Six-cylinder cars only · sources: What Breaks BMW 8er guide, general B58/B57 owner reports

Convertible roof mechanism and seals

Disputed

On the G14 convertible, owners report wind noise and water ingress from the frameless window and roof seals, and occasional roof faults where it stops mid-cycle, usually put down to a microswitch or sensor rather than the fabric itself. It's a common gripe on convertibles generally and opinion is split on how much of it is a genuine design weakness versus normal wear that any soft-top gets. A roof that won't finish its cycle is usually a fixable sensor issue rather than a full mechanism replacement.

Convertible only, reported from 30-50k miles · sources: What Breaks BMW 8er guide, owner forum threads

Viewing one? Ask this

Built from the two sections above.

On an E31, pop the sill trim or feel underneath around the jacking pad sockets. Crumbly or flaky metal there means the sill is rotten from the inside, not just surface rust.
Ask to see the recall/campaign history on the V5 or via BMW, checking the starter motor fire recall specifically. If it shows as outstanding, or only shows the earlier partial fix, budget for a dealer visit before driving it hard.
Start a V8 car stone cold and watch the exhaust in the mirror. Blue-tinged smoke on startup that clears after a few seconds points to worn valve stem seals.
Check the coolant level and look for staining low down at the front of the engine. A car that keeps needing coolant topped up with no visible leak on top may be weeping from the V-valley pipework underneath.
On a diesel, check for a recent AdBlue or EGR-related fault in the service history. Repeat AdBlue faults or an EGR cooler already replaced once suggests it's a car that eats these parts.
Cycle the roof fully on a convertible, twice. Hesitation, an error message, or it stopping partway usually means a sensor or microswitch needs attention.
Idle the engine for a minute or two on a warm car and listen for chain rattle. A metallic rattle that fades once oil pressure builds is the timing chain guides wearing, worse on higher-mileage V8s.

Others in its class

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