WHAT TO LOOK FOR
The perfect body
The Imp’s bodyshell was poorly rustproofed when it was new, but it is strong. It takes major corrosion to weaken the structure, but rot can strike anywhere, so be sure to check the leading edge of the double-skinned bonnet, the bottoms of the doors, the front and rear wheelarches and the sills.
Suspension of disbelief
Examine the floorpan and the rear suspension pans which seat the coil springs. These corrode potentially to the point where the springs go straight through. The mounting points also dissolve, allowing the springs to crash through the bodywork. At the front, the box-section swing axles can dissolve and, once corrosion takes hold, the suspension is weakened. Bear in mind, too, that only used parts are now available.
Keep your cool
The all-aluminium engine lasts well, but only if it’s been looked after properly. If the antifreeze concentration drops, the alloy disintegrates as a result of corrosion, the radiator gets clogged up with debris and the engine overheats. Cylinder head gasket failure is given away by white mayonnaise on the underside of the oil filler cap, and if things are really bad, the block can warp as well as the head. Both of these can be skimmed, but only so much metal can be removed before either unit is reduced to scrap.
In the pink
Listen for pinking as you accelerate through the gears, which belies either incorrectly set ignition or a cylinder head that’s been skimmed one too many times, raising the compression ratio. The only fix is to fit a decent used cylinder head, but, at £30, that’s not a costly undertaking. Post-1966 engines got a much stronger block, identifiable by the straight edge along the top of the cylinder block; earlier ones got a curly edge.
The water temperature gauge should settle at the one-third to halfway mark when cruising. If the engine stays cold the thermostat is either faulty or has been removed to mask a more serious cooling problem. The water pump should be changed every 25,000 miles; they fail even more quickly on rarely used cars, because the bearings tend to fail.
All Imps got a four-speed, allsynchromesh manual gearbox which should be a joy to use. Notchy or imprecise gear changes suggest that the nylon bushes at the base of the gearstick are worn and need to be replaced, but this is a cheap and easy job – a new kit costs just £8. The synchromesh on first and second gear is notoriously weak, so if there’s a crunch when you change gear, the gearbox will be due for a rebuild; exchange rebuilt transmissions cost around £300.
A heavy clutch pedal points to a faulty slave cylinder or a hydraulic hose that’s collapsed internally. Fixes are easy and cheap, but if the bite point is at the end of the pedal’s travel the clutch will need renewing. This means taking the engine out, but it’s not a hard job. The driveshafts incorporate Rotoflex couplings that perish. There aren’t any symptoms as such, but a visual check will show if the rubber has perished or split. New replacements cost £80 each, but cheap or old stock items are a false economy.
On the rack
The rack-and-pinion steering should be light and precise. Any heaviness or play suggests the kingpins and their bushes have worn. Jack up each front corner, hold the top and bottom of each wheel and rock it to check for play; any discernible movement means it’s time to replace the kingpins and bushes. A kit of parts for both sides costs £30; reconditioned kingpins are £90 each. Also check for worn rear wheelbearings – they’re £30-40 per set, but are hard to find.
Keep in trim
Interior trim is very scarce, although used parts are available within the club. The seats of MkIII cars (post-1968) aren’t easy to repair because they’re moulded, but earlier cars’ interiors can be patched up relatively easily. Exterior trim is similarly rare. Badges are Mazak and hard to restore – the rest is either anodised aluminium or stainless steel.