WHAT TO LOOK FOR

A DOZEN OR HALF?

The XJC came with 4.2-litre straightsix (XK) or 5.3 V12 engines, the former being the more common. Scrutinise the service history, ensure the oil is clean and budget for a rebuild as soon as the engine shows signs of wear. Delay things and the bills will quickly mount, especially if something breaks. Antifreeze levels must be maintained on both engines to stave off internal corrosion. Expect oil pressure of 40psi when cruising and some oil consumption is normal, but lots of smoke on the over-run or when the throttle is blipped points to hardened valve stem seals or worn valve guides. Expect to pay at least £1500 for the work to be done, but complications can take this higher.

AVOID AN ENGINE REBUILD

The rear crankshaft oil seal can fail, which necessitates a complete engine rebuild; even on a DIY basis this will cost £5000-plus if done properly. XJ Restorations’ Keith Parrington says: ‘We charge at least £11,500 to fully rebuild a six-cylinder engine while a V12 is upwards of £20,000 – that includes removal and refitting. Cutting costs means having to use sub-standard parts. Ensure the oil has been changed frequently, that anti-freeze levels have been maintained, and look for signs of previous overheating – which can scrap an engine. Undertake a long pre-purchase test drive and allow the car to idle for as long as possible. Watch for any unusual activity with the temperature gauge.