UNDER PRESSURE

QMy Lada Riva’s oil pressure light came on suddenly at some traffic lights. It now stays on until quite high rpm before going out. It had never misbehaved previously. Is the engine doomed?

Phil Vega, Dunstable

AStart by simply gambling £5 on a new oil pressure switch. If no joy, then a piece of debris might be jamming the pressure relief valve open. Remove and inspect the pump. While you’ve got the sump off, look for any exposed drillings in the crankshaft – they should have little plugs in their ends. These can occasionally come loose or pop out, causing a sudden loss of pressure. There’s not much else to check, aside from the drive to the pump itself. The engine should be good to go once you’ve found and solved the problem, as long as you didn’t drive it all week with the light on.