Hi, first post on here. I have an 08 2L x type diesel saloon in fantastic condition with 71K genuine miles. Experiencing no engine brake with engine run on. To explain, in town, at junctions, roundabouts etc., when slowing and gearing down, foot off the accelerator and releasing the clutch, the car does not slow with any engine brake and in fact, speeds up! Basically, slowing to around 10 - 20 mph, and I decelerate I depress the clutch and revs drop. When the clutch is released, the revs increase and the car speeds up. Why? What would cause this and what’s the cure? TYIA. Drew.

 

I have experienced exactly the same with a ecu remap.
The mapper altered some maps that he should not have.
Pressing the clutch would temporarily cancel the acceleration, but would start to return after approx. 10 seconds.
Have you recently bought this car, if so sounds like a bad remap.

As the revs drop when pressing clutch pedal, due to switch on it, it will not be a turbo ingesting oil problem.

Paul.