My astra is starting to show, and feel, it's age. 8 years old and coming up to 98,000 miles. It needs a new oil pickup seal, which involves taking various bits off and dropping the sump (to replace a £25 seal). The prices I've seen on various forums range from £300 to £400 to a sharp intake and flat refusal. It's giving me a 'service vehicle soon' on startup, which means it needs one (or, possibly, more) glow plugs at £120 a pop. MOT and service are coming up in three months. It's tatty. My fault for not getting scratches and scrapes done as soon as they occurred. Both front doors from car parks and front bumper both sides from me being gozzy. Had a quote last year from a well recommended local lad for £450, but I've added another door since then.
Under normal circumstances, it would be down to WBAC, and me accepting whatever they offered. But used car prices are still way too high for what you actually get. So, as I say, decision time soon.
If you're being 100% honest with yourself, is it that you are worried the car really is on its last legs? Or are you just fancying something newer/better/tidier/different?
I'd be surprised if an 8 year old car is going to be problematic, and just with a couple of hundred quid on the engine fix (can they will have to do an oil change, so thats the service checked off as well), so if its you are genuinely worried, its probably unfounded.
On the other hand, if its you fancy a change, well, why not?