Recently my i30 estate has developed an intermittent problem that if you accelerate quickly, as in third gear, the car appears to enter some form of rev limited mode, with a loss of power/dull response around the 3000 rpm. The only way that you can clear the problem, is to stop the car, and restart it, not completely proven it, but the problem doesn't appear to manifest itself if you disable the ESP mode. The car has now twice been in to the main dealership, and has been check, including a diagnostic check, but the garage cannot find anything to suggest what is causing this rather unnerving problem, any thoughts? The car is an 11 plate.
Update: 05/12/2013 - On the way to work this morning, the car cut out as I was braking in a line of traffic, once restarted, the above referenced problem became more regular, until the engine management warning light illuminated, and didn't clear once the car was restarted.
I managed to get the car to the garage in 'limp' mode, and the fault was diagnosed to a diesel 'waxing' issue with the fuel filter, which was duly replaced, and the problem would appear to have been resolved.
The service manager explained that there would appear to be an issue with fuel additives generally causing this issue, but I never use supermarket brand fuels, and almost 100% only fill the car with Shell brand.