a) 1.6L M43 and 1.6L N42 Engine Characteristics in BMW E46 316i:
- 1.6L M43 (105 bhp at 5300 rpm, 150 Nm at 3900 rpm) up to 2001
- 1.6L N42 (115 bhp at 5700 rpm, 150 Nm at 3750 rpm) from 2001
- Both use chain-driven timing; designed for lifetime of engine but can stretch
- M43: Listen for rattling noise at startup, indicating chain stretch
- N42: Check for rattling at idle, could indicate worn VANOS seals
- Timing chain replacement interval: Not specified, but typically needed around 150,000-200,000 miles if issues occur
- Timing chain replacement cost: £800-£1000 at independent specialist
- Recommended oil: 5W-30 or 5W-40 fully synthetic, capacity 4.25 litres
- Oil change interval: Every 12,000 miles or annually, whichever comes first
- Oil consumption up to 0.5L per 1,000 miles is considered normal
- Check for leaks around valve cover (common on M43) and oil filter housing
- Inspect expansion tank for cracks; replacement cost: £70-£90
- Check water pump for leaks; listen for bearing noise. Replacement: £150-£200
- Water pump typical lifespan: 60,000-80,000 miles
- Thermostat failure common; look for temperature gauge stuck at 1/4 or 3/4
- Thermostat replacement cost: £100-£150 including labour
- Coolant flush recommended every 3 years or 36,000 miles
- Examine for rust, especially middle section and back box
- Listen for exhaust blows indicating holes or failed gaskets
- Catalytic converter issues less common in 316i, but check for rattles
- Full exhaust system (excluding manifold) replacement: £400-£500
- Listen for clunks over bumps (worn ball joints or bushes)
- Check for uneven tyre wear suggesting alignment issues
- Front control arm bushes replacement: £180-£220 for parts and labour
- Shock absorbers typically last 60,000-80,000 miles
- Full suspension refresh (bushes, shocks, springs): £800-£1000
- Front: 286mm discs, Rear: 276mm discs
- Inspect for scored discs and uneven pad wear. Minimum pad thickness: 3mm
- Brake fluid change interval: Every 2 years regardless of mileage
- Full brake service cost: £220-£280 at independent garages
- ABS sensor failure common; replacement cost per sensor: £60-£80
- Manual: 5-speed Getrag. Check for smooth changes, no grinding especially in 2nd
- Automatic: 5-speed GM 5L40-E. Ensure smooth shifts, no slipping or harsh engagement
- Gearbox oil change interval: Every 60,000 miles
- Manual gearbox oil change cost: £100-£130
- Automatic transmission fluid and filter change: £180-£220
- Major automatic transmission repairs can be costly:
- Valve body replacement: £800-£1200
- Full rebuild: £1500-£2500
- Replacement with reconditioned unit: £2000-£3000 - Signs of automatic transmission issues:
- Delayed engagement when shifting from Park to Drive
- Slipping gears or sudden jerks during acceleration
- Unusual noises (whining, humming) when in gear
- Transmission fluid leaks or burning smell
- Test all electrical components (windows, central locking, A/C)
- Check for airbag warning lights; seat sensors often fail (£150-£200 to replace)
- Ensure cooling fan works correctly when engine is warm
- Window regulator failures common; replacement cost: £120-£150 per window
- Inspect bottom of doors, especially front ones, for rust
- Check rear wheel arches and boot seal area for corrosion
- Look for bubbling paint on bonnet near windscreen
- Sunroof drain blockages common; can lead to water ingress
- Check driver's seat bolster and steering wheel for wear
- Ensure all dashboard lights work, including instrument cluster
- Test air conditioning; regas cost: £60-£80, compressor replacement: £400-£500
- Look for regular oil changes (every 12,000 miles or annually)
- Verify mileage against MOT history and service records
- Major service interval: Every 36,000 miles or 3 years
- Spark plug replacement interval: Every 36,000 miles
- LCI (from 2001): Clear indicator lenses, restyled rear lights
- Interior updates include new steering wheel design
- N42 engine introduced in LCI, offering more power and efficiency
- M43: Coolant leaks from expansion tank and radiator
- N42: VANOS solenoid failures causing rough idling (£300-£400 to repair)
- Both: Camshaft sensor failures leading to poor starting (£80-£100 to replace)
- Listen for unusual engine noises, especially on cold start
- Check for smooth acceleration and gear changes
- Test brakes for even stopping power and no pulling to one side
- Drive over speed bumps to check for suspension noises
- Ensure V5C is present and matches the car details
- Check for outstanding finance using HPI check (cost: £20)
- Verify MOT history for recurring issues and mileage consistency
- 316i less commonly modified, but check for non-standard parts
- Aftermarket air filters or exhaust systems may affect performance
- Ensure any modifications are properly documented for insurance
- More refined than equivalent Vauxhall Astra or Ford Focus of the same era
- Less powerful but potentially more reliable than some rivals
- Higher prestige factor, but typically 15-20% costlier to maintain than mainstream brands
- Annual service: £140-£180 at independent garages
- Major service (every 36,000 miles): £280-£350
- Timing chain replacement (if needed): £800-£1000
- Budget £400-£600 annually for maintenance on a well-used example
- Good availability of both OEM and aftermarket parts
- Example prices:
- Oil filter: £8-£12 (Mann or Bosch), £15-£20 (OEM BMW)
- Air filter: £15-£20 (Mann or Bosch), £25-£30 (OEM BMW)
- Brake pads (front): £30-£40 (Pagid or Brembo), £60-£70 (OEM BMW)
- Shock absorbers (pair, front): £100-£120 (Bilstein), £180-£200 (OEM BMW)
- As of 2023, average asking prices:
- Under 80,000 miles, excellent condition: £2,000-£3,500
- 80,000-120,000 miles, good condition: £1,500-£2,500
- Over 120,000 miles, fair condition: £1,000-£1,800
- Well-maintained, low mileage examples (under 60,000 miles) can fetch up to £4,000-£4,500
- Annual depreciation now typically 5-8% for well-maintained examples
- Prices can be 10-15% higher in London and South East England
