Hi - hopefully somebody can help! Car went in to Audi with a running problem - suspected injector problem. Comes out and I'm told the injector seat is worn (and so is the injector itself). They showed me the fuel from the filter and it's black. They've refitted the injector and replaced the fuel filter(s) saying the car is 80% better but they can't say how long the fix will last..... The 'Audi' solution is to replace the head (which depending on tolerances may also require a new block) and replace both fuel pumps and clean out the fuel lines and fuel tank. I understand the Audi solution is the 'guaranteed' fix but between £4 and £8k it becomes non-viable .... and risky Apparently worn injector seats is a common thing on diesels and doing some research on the internet reveals a variety of 'seat cutters'. Talking to a couple of garages they don't seem too keen to do this. In my mind surely cutting away metal will mean the injector will sit further inside the engine? Is this OK? Any experiences or advice much appreciated!