Hi I have a Ford Fiesta - 1.4 Tdci [70] Zetec 5dr Hatchback 2010. The car is a lease car through work and has 27655miles, the 1st svc was at 14113miles on 23/1/12, and the car was due a 25k, 2k miles ago and I planned to do after xmas period.
Recently I was driving on a motorway around 70mph. All of a sudden the engine revs shot up very high and engine began running on its own accelerating uncontrollably. Plooms of white smoke came from rear and I had to stall the car to stop it.
Since the car was last serviced I had used 1 litre of oil only when the oil light came on. The dip stick showed to be at the maximum level on checking this. This was around 1 month to 6 prior to the incident. There had been no difference in the performance of the car until the incident occurred. On recovery of the car the recovery driver suggested that it was the turbo that was at fault. Three different people checked the dip stick (recovery man, fireman, and RAC inspector) and none reported oil to be over the max level.

However the main dealer is reporting engine and turbo damage due to engine oil being overfilled, the dealer says this is not covered by warranty. At time of their inspection they report the engine oil over max and that the engine has over revved. They report compression on only one cylinder and turbo impeller stiff to turn. They say the car requires, an engine, turbo and DPF and possibly injectors. After draining sump they report oil overfilled by 2.5 litres despite that which was burnt during the incident. They want to carry out compression test once auth'd. No DTC's relevant to concern.

As I have disputed this the dealer who wants to send in an engineer to assess the work required and confirm why not covered by warranty, the inspection will need the engine out and cylinder head off for a full report, if proven not warranty the inspection costs and diagnosis time costs would then be rechargeable to me.

I don’t know what to do about this situation and am obviously very worried that this is being put down to being my fault and will incur major cost (which I don’t have). I know I have only put 1 litre of oil in the car around 4-6 weeks ago and don’t understand why if this was the reason:
1. The car didn’t fail sooner or immediately after the oil was added but ran as normal (would this not happen immediately?)
2. How it could be over filled by 2.5 litres when I only added 1 litre
3. Why the level on the dip stick did not indicate it was over filled.

I am aware that further investigation may shed some light and rule me out as being responsible but I am concerned that this won’t make any difference as I am not a mechanic and can’t prove anything. I got a lease car so I didn’t have the worry of costs and obviously don’t want to incur additional costs as I don’t have this sort of money. I have been told I need to get my own inspection
But again don’t have the money to have this done. Are there any other possible causes that you know of that may have caused this? Any advice you can give would be very much appreciated.

Helen