"Треск цепей BFM прощай! — Chain rattle on the BFM is a well-known community headache requiring oil system modifications to resolve."
RISKY
52/ 100
"Big power, bigger bills, chain rattle lurks"
563
Max HP
900
Torque Nm
8,000
Oil interval km
0
Recalls
3
Known issues
Known Issues
Timing Chain Rattle and Tensioner Failure€2,000-5,000 · 80,000-180,000 kmCRITICAL
The BFM engine is known for timing chain noise and tensioner issues. Community discussions highlight the chain rattle as a defining problem of this engine, with fixes involving oil pressure modifications such as installing a check valve in the pressurised oil gallery to maintain chain tensioner pressure after cold starts.
Rattling noise on cold start from front of engine
Rattling that diminishes as oil pressure builds
Persistent chain noise at idle
DIY: Expert
Fuel Pump and Fuel Delivery Issues€400-1,200 · 80,000-160,000 kmHIGH
Forum data reports BFM-specific fuel delivery problems including misfires, poor acceleration, backfiring through the exhaust, and worst behaviour on cold starts after extended standing. The fuel pump is identified as a suspect component.
Misfires on cold start
Backfiring through the exhaust
Hesitation and refusal to accelerate
Rough idle after long periods of standing
DIY: Moderate
Oil Pressure Loss Due to Drain-Back€300-900 · 60,000-200,000 kmHIGH
Oil drain-back from the chain tensioner galleries during engine-off periods contributes to momentary low oil pressure and chain rattle on restart. Community solution involves retrofitting a check valve in the oil supply line to the tensioners.
Chain rattle immediately after cold start
Oil pressure warning light on start-up
Noise disappearing once pressure builds
DIY: Moderate
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Buying Checklist
Cold-start the engine and listen for timing chain rattle before oil pressure builds — walk away if rattle persists beyond 5 seconds
Ask specifically whether the check valve retrofit has been fitted to the oil supply gallery to prevent tensioner drain-back
Request full service history showing oil changes at or below 8,000 km intervals with approved 5W-40 fully synthetic oil
Run an OBD scan for fuel trim, misfire, and oil pressure fault codes before purchase
Test fuel delivery by checking for hesitation, backfiring, or rough cold-start behaviour after the car has sat overnight
Inspect all accessible engine ancillaries for oil leaks, particularly around the timing cover and valve covers given engine age
Est. ownership cost (2yr)€2,500–6,000 per year depending on condition and deferred maintenance
Real mix fuel consumptionNo data
Also Found In
Audi A8 D3 4.2 Bi-Turbo (S8 variant)
Buying Advice
The BFM is an extremely powerful and exotic unit that demands respect and significant maintenance investment. The timing chain rattle is the engine's most notorious weakness and must be assessed on every cold start before purchase — untreated, it can lead to catastrophic engine failure. Only buy a well-documented example with short oil change intervals and ideally evidence that the chain tensioner oil check valve modification has been carried out. Budget generously for ownership; parts and labour on a 6.3-litre bi-turbo V12 unit are never cheap.