A ticking noise from the engine of a modern car is often the first signs of a build-up of sludge inside the engine. The hydraulic lash adjusters (which control the amount of clearance in the valve-train) operate on the same oil that lubricates the entire engine. If sludge has begun to build up in the engine, these lash adjusters are often the first components to be damaged.

What causes this build-up? Most commonly, the cause is poor servicing over the years. If a previous owner has stretched the oil-change intervals beyond the factory recommendation, the oil becomes contaminated and dirty and that leads directly to sludge. Does your car have a written record of its past maintenance? If not, I’d be very suspicious of its service history.

You may be lucky, however, and simply have a single lash adjuster that has failed for no good reason. If that’s the case, it can be replaced (I’d replace all 16 of them while I was at it). Perhaps in the first instance, the wise move would be to have somebody who knows these engines have a listen to see if the cause is something else. Modern aluminium engines can often be a bit noisy, and your problem could be related to an injector or fuel pump or perhaps something even deeper inside the engine.

The tappets are not adjustable, and it’s not normal that they are noisy. It’s hard to know what has happened as a result of it standing for so long. Have a mechanic check the tappets.

It should run on 91-octane fuel without pinging; the knock sensor should ensure that it doesn't occur. Running it on higher-octane fuels makes it less prone to pinging, and again the knock sensor should have it running on the edge of pinging without actually doing it. I would keep the pressure on Kia to fix the problem, and at the same time get the help of an independent mechanic.