Hi, I have a Ford Mondeo 2.5 Turbo Ghia (2007) 4 door saloon. Recently I've noticed that after the car has been running for about 15 minutes, if i put my foot down there is a momentary loss of power, the car bucks and I have to ease off on the accelerator for it to run ok again. This also occurs from a standstill, at traffic lights for instance, I depress the accelrator and the car jerks and bucks, i have to ease off and creep forward to get the car moving but it's not every time although it will do it at some point on every journey over 15 minutes.
I've taken the car to an indie garage and they've witnessed the fault but the scanner doesn't give a fault code. They've said that they'll have to have it back to give it a general check over of wires and hoses etc to find the fault. The mechanic said he felt it was electrical. He said it's almost like someone is flipping a switch to turn the engine off for a split second and back on again repeatedly.
I've done a bit of research and have seen things like fuel injectors, fuel filters, egr valve etc but none of the symptoms of those things quite match what my car is doing. i.e there's no balck smoke, no horrific noise when idling etc. The car runs smoothly at lower speeds although there is a slight bumpy/lumpy feeling as I'm driving at say 70mph+ not that i do that of course!!
I've noticed that this problem is worse when the weather is damp although there have been relatively few dry periods over the last few months so i can't say for sure that its a contributing factor.
I've arranged to take the car back to the garage in the next few days and I'd love to be able to give them some idea where to start as i have a feeling the trial and error approach is going to be expensive
Any help would be much appreciated!!