You’re spot on when you say pinging won’t be good for the engine long term, but even in the short term, this needs to be fixed to prevent serious engine damage. The best advice is to find a mechanic or workshop that is experienced in this make and model and tap into that experience.

Fundamentally, the main causes of engine pinging (or detonation or pre-ignition, call it what you will) are a lean air-fuel mixture, incorrect ignition timing, fuel with an insufficient octane rating, carbon build-up inside the engine or an engine that is running too hot. None of these things should be hard to spot for the right mechanic.

The government has, indeed, made changes to fuel quality standards, but none of these should have affected the octane rating (or RON) of the fuel. In fact, there are mandated Standards for fuel octane, although that doesn’t rule out the odd bad batch. Do you fill up at the same service station every time? It might be time to try a new one.

Your car has an engine Suzuki calls K12C which is a member of the Dual Jet family. That means it does, indeed, have a pair of fuel injectors for each cylinder. It’s conceivable that one set of the injectors is not seating properly or not getting the correct signal to shut off from the computer and that is filling the cylinders with fuel. This may happen until the pressure in the fuel rail dies off, or it could continue dripping all night.

If this is what’s happening, then you shouldn’t attempt to start the car as, should there be enough fuel inside the cylinders, the engine could hydraulically lock, potentially bending con-rods and destroying the entire engine.

How have you diagnosed this as the problem? Have you removed the injectors and had them checked or tested? This sounds like a pretty odd sort of problem for a car as new as this.

The other possibility is that the injectors are getting a computer signal they shouldn’t and leaking as a result. This is a tempting theory as it might also explain why the fan continues to run with the engine switched off. However, it pays to remember that many cars will continue to run their cooling fan after the ignition has been turned off as a way of reducing the temperature of the engine, even though it’s stopped. This should have no effect on the injectors, though.

Replacing random parts to fix a problem is a great way to tear up dollars and time. It’s also pretty frustrating when the problem doesn’t go away. The first thing to do is to have the car electronically scanned to see if the car’s own computer can point you towards the cause of the problem.

It may be as simple as the car needs a tune up and a new set of spark plugs, but you won’t know until it’s been properly diagnosed. This is not a complex car, so any good workshop should be able to sort it for you. The other problem, of course, is that the issue is intermittent, so it may take the workshop some time to be able to make the problem appear. Patience is the key here, not throwing a load of new parts at it.