Car Mechanics (UK)
Problem with acceleration
My vehicle is a 2006 VW T5 with 107,000 miles on the clock. When the ignition is turned on, the acceleration is instant and the van drives like a GTI. Then, after approximately four miles, it is not as instant and drives like a standard Golf. When I stop for five to 10 minutes and restart, the acceleration is like a GTI again. This has happened since I bought the vehicle in 2009. Is this a characteristic of this van?
I have replaced the following parts: the MAF, CTS, MAP, TBPS, fuel boost senor, EGR cooler, N75 water temp sensor, EGR valve solenoid and pressure valve. The EGR and turbo have both been cleaned. The intercooler has also been replaced and the DPF removed and the ECU remapped. I have also had the fuel tank cleaned out. The vehicle has been regularly serviced at 48,000, 60,000, 72,000, 84,000 and 95,000 miles.
My first comment would be that, due to recent changes in legislation, it is no longer legal to have the DPF removed and this will need replacing to comply with MOT regulations.
Looking at the list of components you have already replaced, this includes the coolant temperature sensor, which would have been my first suggestion. It is hard to say exactly what the problem may be and, from what you write, it is not bad when warm but very good when cold.
As the original acceleration is returned after switching off and on again, this is most likely the result of an electrical item resetting. I would advise getting the system read for any fault codes and would check the live data for any irregularities in the given data. You do not say if the ECU was remapped, but the symptoms may be a result of the remapping.