1 HOw’s THe eNGiNe?
The XK straight-six engine demands regular maintenance, so scrutinise the paperwork to make sure that it’s been looked after by the car’s previous owners. Ensure it doesn’t sound rattly, look for an oil pressure of at least 40psi at 2500rpm, and beware lots of blue smoke when you blip the throttle – a common symptom of worn valve guides.
2 lOOk MOre clOsely
A 420 that looks sound on the surface can harbour big trouble when it comes to corrosion, so try to get a car up on a ramp and look carefully. Key places to look include the jacking point beneath the A-post, and where the chassis legs join the crossmember. Inspect the panels carefully for bubbling paint or signs of surface rust, particularly at the front and rear end where parts aren’t shared with the Mk2.
3 iNsPecT THe TriM
Take a look carefully at the quality of the cabin, particularly on the Sovereign models, for which Browns Lane fitted additional dashboard padding and higher quality Connolly leather for the seats, which can be extremely difficult to source if it needs to be replaced. If an interior needs a complete leather retrim it can easily add up to more than £2500 for a specialist to complete the work properly.
4 wHeN TO sTeer clear
If the car’s been fitted with the Varamatic power steering system – and plenty were, as it was a popular option on both the 420 and Sovereign when new – then inspect the unit carefully for any signs of leaks. Check how it feels carefully on a test drive – it should feel smooth, light and precise, so beware any cars that steer sloppily or have excessive amounts of play or juddering.