TIMING CHAIN - The timing chain, or more specifically the tensioner, is the weak spot. Keeping the oil topped up is vital but ultimately poor design is to blame. A rattle and brushing noises at idle from cold is the tensioner’s ‘death rattle’.
OIL LEAKS AND MISFIRES - Oil leaks are becoming an issue on older cars. Check the rocker cover, crank seals, sump, turbo oil feed, front and rear main bearing seals, solenoids and cylinder heads for drips. Valve stem seals are starting to fail on older cars. Permanently low oil allows sludge to build up in the Vanos valve control system, affecting performance. Hesitation, uneven idling and misfiring could be carbon build-up on inlet valves or failing coil packs.
COOLANT SYSTEM - Look for cracks on the plastic coolant thermostat housing. Check if the water pump has been changed; it’s best done at around 50,000 miles. Check the plastic lower radiator support – it’s prone to kerb damage.
TRANSMISSION - Check the clutch operation – failure as early as 20,000 miles isn’t uncommon. Worn synchros are rare so graunching suggests seriously hard use. Feel for a harsh shift on autos, often caused by a faulty valve body which could require a rebuild or replacement of the gearbox.
SUSPENSION AND BRAKES - Check the front wishbone bushes, which have to work hard. The anti-roll bar bushes have an easier time.
Also worth knowing:
Earliest R56s are 12 years old and the suspension, while sophisticated, isn’t the most adept and will probably be in need of a refresh. For less than £1000, you can replace wishbone bushes, springs and dampers with upgraded polyurethane bushes, Koni shocks and Eibach springs.
How much to spend:
£2300-£3495 - Launch cars with around 100k miles, generally good histories and in serviceable condition.
£3500-£4995 - Lots more lower-mileage 07 cars (circa 75k miles), with more lower-mileage 08s and 09s towards £4995.
£5000-£6995 - Very low-mileage 07s but many more 08 to uprated 10-plate cars with decent mileages.
£7000-£8995 - A good choice of proper 10 to 13-plate cars.
£9000-£10,500 - Plenty of low-mileage 11 to 13-plate cars here, the most expensive being a 2012 with 19k miles and £5000 of extras including powered panoramic sunroof.