BMW M5
High-revving V8 naturally aspirated engine with 8 individual throttle bodies and double VANOS. The characteristic ITB intake sound snarls metallically from 5,000 rpm and peaks at 8,000 rpm in a V8 howl that exists in no turbo BMW. Compared to the predecessor S38: more displacement, more torque, two camshafts per bank. Last BMW M naturally aspirated engine above 400 hp — the concept was never repeated. Preventively replace timing chains and con rod bearings (100,000–130,000 km). VANOS rattle is nearly universal but not a knock-out criterion — an anti-rattle kit should be fitted. Check the viscous fan coupling (holding test). Read all 8 throttle body potentiometers with GT-1. Pre-facelift engines (before 9/2000) consume more oil but are less affected by land-bridge burn.
8 throttle bodies, 6-speed manual, 400 hp NA
Below 4,000 rpm a cultivated V8 tourer. Above that it becomes clear why the E39 M5 is a legend — the ITB howl builds into a wail that ends at 8,000 rpm because the limiter arrives, not because the engine couldn't go further. Manual only, 1,795 kg. Rod bearings are the sword of Damocles — whoever has them done has the last great naturally aspirated M5 ahead.
Engine Weaknesses 10
The connecting rod bearings of the S62B50 are on the tight side by design. At high mileages or with poor oil maintenance they can fail. Preventive replacement from 100,000 km is recommended on track-day vehicles.
Symptoms: Deep knocking from the lower engine at operating temperature, metal particles in the oil filter, oil pressure drop
As on the M62, the plastic timing chain guide rails of the S62B50 become brittle with age. The involved repair requires almost complete engine disassembly.
Symptoms: Rattling on cold start, progressively louder chain noise, VANOS fault codes
The S62B50 uses Alusil coating instead of iron liners. Extremely narrow cylinder lands leave little scope for repair. Scoring occurs through contamination or oil starvation. Engine overhaul with a replacement block is usually more economical than honing.
Symptoms: Increased oil consumption (>0.5 L/1,000 km), exhaust smoke, measurable compression loss, longitudinal scoring visible in bore with endoscope.
On facelift S62B50 engines (from 9/2000), land burning between cylinders 7 and 8 is documented. The cause is higher thermal stress. Pre-facelift engines consume more oil but suffer land burning less often.
Symptoms: White exhaust smoke (coolant burning), coolant loss without visible leak, oil and coolant mixing, compression loss in cylinders 7/8.
The O-rings in the S62 VANOS harden and lose their seal. Damaged solenoid valves can score the valve seat bores and make the housing unusable. BMW part number O-ring: 11367833218.
Symptoms: Rough idle, power drop at low revs, rattling on cold start, possible oil ingress into intake system.
The S62B50 has eight individual throttle bodies, one per cylinder. Each cylinder bank has one potentiometer on the throttle shaft. Wear or contact faults trigger limp mode. Both potentiometers should be replaced simultaneously.
Symptoms: Engine goes into limp mode, power limited, jerky throttle response, fault message 'throttle potentiometer bank 1/2', misfires at part throttle.
The S62 thermostat opens at just 79°C. If it fails, the main cooling circuit does not open correctly. The viscous fan coupling wears — with a slow fan, temperatures in city traffic can reach critical levels.
Symptoms: Coolant temperature rises above 90°C in city traffic, fan can be stopped easily by hand on a hot engine (= failed viscous coupling), coolant boils in traffic jams.
The V8 high-performance engine develops oil loss at the cam covers and sump at higher mileages. Regular oil level checks are mandatory on this engine.
Symptoms: Oil loss, oil puddles under the vehicle, dropping oil level, oil smell on a hot engine.
The secondary air pump of the S62B50 frequently fails through worn carbon brushes or a faulty check valve. The result is a fault code and emissions warning light.
Symptoms: Engine warning light (P0410/P0412), howling noises on cold start, elevated emissions at MOT
Eight individual coils fail one by one through ageing or WOT stress. Unlike many engines, all eight do not need to be replaced at once on the S62 — but always replace a faulty coil together with the one on the opposite bank.
Symptoms: Misfire and stumble under load or at WOT, warning light 'misfire cylinder X', rough running after full-throttle acceleration.
Vehicle Weaknesses 7
The rubber mounts of the differential in the rear subframe harden and break with increasing age. The differential can shift under load and produces jolt on gear changes.
By design, water collects in the filler neck area and rear wheel arches. BMW switched to water-based paints around 1999 with initially suboptimal formulation.
Thermostat tends to stick in the open position. Plastic radiators can crack at the tank seam. Thermally more stressed in the S62 than in the standard E39.
OEM rubber of the centre bearing dries out and cracks after just 5–10 years regardless of mileage. The bearing no longer centres the propshaft.
The ribbon cable between the main board and LCD display loses conductivity through ageing. Affects virtually all E39s past a certain age.
The large M brake tends toward uneven brake pad transfer after hard use, which manifests as steering vibration under braking.
The memory module for electric seat and steering wheel adjustment fails and loses stored positions.
Reports & Tests
46 owner complaints filed with NHTSA (1998–2003). Most reported: Airbags (14), Powertrain (5), Electrical (5).