Hyundai SUV Range

This model Hyundai i40 had two different automatic transmissions depending on which engine was fitted. If you have the petrol engine, the transmission will be a conventional torque converter six-speed automatic. However, if your car has the turbo-diesel engine, the transmission will be a seven-speed dual-clutch unit. At which point things change.

These dual-clutch units (and not just Hyundai’s) have shown themselves to be a bit under-engineered in some respects. And when they start to develop wear in the clutch packs, they can definitely start to behave poorly including rough shifting, shuddering when moving off and other problems.

But either way, you are going to need the services of a transmission specialist to determine what’s wrong. Even if you have the conventional automatic version, you might still find it has serious internal wear or failures, but only a detailed diagnosis will tell you the whole story.

On the other hand, you might be lucky and simply have a transmission with low fluid level that will be restored to health by a top up of that fluid. You’ll still need to find from where it’s escaping, however, as this is a sealed system and should not lose fluid over time.

Most Hyundai engines with a rubber timing belt require belt changes every 100,000km. Stretching this interval is pushing your luck as a failed belt will destroy the rest of the engine. With that in mind, you’re already over that limit by about 10,000km, so a change sooner rather than later is in order.

The car will, indeed, drive perfectly even with an old timing belt. Until it doesn’t. At which point you have an engine bay full of junk and a big engine replacement bill coming your way.

A poor earth is often the cause of this sort of misbehaviour and it’s a good place to start looking. Check the earthing points in the engine bay and around the area where the tail-lights are earthed in the cargo area.

You might need to lift some carpet or trim pieces, but when you find the earth points, make sure they’re tight and clean and not covered in corrosion. Don’t forget to check the tightness and cleanliness of the battery terminals, too.

Beyond that, these symptoms point to a problem with the car’s body computer which controls all these functions and many more.

When this computer starts to die, all sorts of weird and random flaws can occur. But try this first: Disconnect the battery of the car and let it sit overnight. Reconnect it next morning and keep a close eye on what happens. Sometimes this simple trick will reboot the body computer and normal service will be resumed. Best of all it’s free.