2005 ain’t particularly old (at least I don’t think so) – you’re making my 2000 truck feel ancient man!
anyways – I always group my vehicle’s sounds, and rate them in severity –
7. body/trim
6. interior
5. exhaust
4. suspension
3. drivetrain
2. engine
1. legal requirements
there’s obvious reasoning: you can’t drive without the vehicle being legal, and the engine works, then the engine can make power go to the wheels.
the successful aging of a car is entirely relative to it’s human. Are you a calm driver? where do you drive? highway? city? potholes? dirt roads? – my biggest observation is that 1 day of hard use on a car isn’t bad – but if you’re the type of person that sees a car’s purpose as such, then prepare for faster deterioration.
How to prevent? firstly stay on top of your fluids – they’re the first telltale sign to engine wear. then stick to your maintenance schedule.
when you find new sounds, it’s very important to find specifically where the sound is coming from, and group it in severity to its function (power steering for example)
yes engines start to make more noise as they age (not going to lie, Kia’s are not yet known to live a long time [the company is still young, no statistics]
mostly due to the expansion and erosion of piston rings, bearings, seals, etc. – some of which are easy to replace, most of which are not, and just accepted as noisemakers due to the cost and effort.
personally I miss the days when cars lasted beyond their owners. The automakers have realised that this is no longer a successful moneymaking strategy and have decided to make worse cars that require more service calls – because it makes money. however overall, your personality as a driver will equate to a longer lasting car.