Picked up a used Carisma a few weeks ago with only 40,000 miles on the clock. Not bad for a car that is 14 years old.

First time I've owned a GDI engine vehicle, knew little about them but after researching I have read up on the carbon build up issues with these motors after a time.

Seems to be running the cheaper fuel in Europe and mineral based oils that are the problem. The throttle body gets caked up, the intake and valves become caked in time too?

Anyway after all that. I decided to change the oil, it was pretty black and needed a change. Unfortunately I got the the wrong filter so I had to refit the old one for now and just changed the oil for a cheapish 10/40 semi.

I have ordered the correct filter now and will give it a second oil change, this time I purchased a better fully synthetic 5/30 oil. At least it will be nice and clean with two changes in a month!!

In Europe (in particular the UK), should I be running 97RON fuel (or whatever super unleaded I can get) and the not the cheaper 95RON fuel?

Seems to be lots of reports of people running the cheaper fuel which cokes up the intake. The previous owner of this car (an old fella) was running it on the cheaper 95 octane fuel.

I am getting random poor idling for a few minutes after starting. The motor will surge, drop off, idle poorly, stall, but will eventually settle. This happens not all the time, often it will start fine and idle fine for days.

The tappets are also randomly quite noisy, especially when the engine is on load, going up a hill or simply stepping on the gas. Again this can happen for ten minutes, then be gone for days.

I'm mechanically minded, removing the throttle body for a clean up would be easy enough for me. Anything in particular I need to know before doing so.

Toothbrush and carb cleaner will do the job no doubt.

Thanks.