UK Car Repair Questions? Ask a Mechanic for Answers ASAP
Hi my name is***** am a diagnostic technician and look forward to working with you.This problem is commonly caused by the accelerator pedal sticking, these engines use drive by wire rather than a cable, as you mentioned normally pulling the pedal back up will cure it temporarily, It is possible the sensor arm is sticking so I would make the peddle assembly the first suspect.The next step would be to get the van plugged into a diagnostic system to view the live data and check for any fault codes in other systems. The live data can give a real time read out of the throttle potentiometer which will quickly and accurately diagnose a throttle pedal or sensor problem.I suspect this is a throttle sensor fault as it is fairly common and exactly the symptoms I would expect but I strongly advise this is checked as soon as possible as there is a small risk this is caused by the turbocharger seals allowing a mist of oil back into the engine intake, diesel engines will run off this oil mist which will cause the engine to increase rpm, this can very quickly cause a positive feedback loop which can cause serious engine damage. A simple way to check for this is to pull off a turbocharger boost pipe near the intercooler or the turbo to check of excessive oil build up. A fine mist is perfectly normal but if oil is dripping or flows out it is a sign of seal failure.
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