Like any Mk2 Mondeo, one of the ST24’s pitfalls is its clutch. Not because it’s particularly weak (it isn’t) but because replacing it is a big job, and the cost of getting a garage to do the work has been responsible for the demise of many Mondeos.
Although clutch failure can occur at a relatively low mileage, it’s more likely on hard-used and high-mileage cars. Check for slip by accelerating hard in fifth gear at 2000rpm; if the road speed doesn’t increase in line with engine revs, the clutch needs to be replaced.
Ensure the pedal feels smooth and light to operate: a tired pressure plate or springs makes it feel notchy or heavy, while a high biting point means there’s not much meat left.
Difficult gear selection may also be due to a tired gearbox, especially if the ST24 has been around the clock a couple of times. Its MTX75 five-speed manual is remarkably tough, but it won’t quite last forever. Stickiness, especially in third, suggests synchromesh wear. Whining or rumbling could point to knackered bearings, although it’s more likely the fault of differential failure; listen for groaning (which sounds similar to growling driveshafts) along with excessive torque steer when driving in a straight line.
Decent second-hand gearboxes are available, of course, as are parts to fix an MTX75. But unless the ST24 is in particularly great condition, replacement may well outweigh the price of the car.
On the brighter side, if you hear clicking when the steering’s on full lock, it means the CV joints are shot. They’re not expensive, but get them changed before they cause damage.