Doctor Diesel

Testing times

Testing timesHi Doc. I’m not sure whether to address this to you or the editor. As the owner of a 2012 Skoda Fabia Estate 1.6 TDI, I am concerned as to where I stand at its next MOT emissions test. Nothing seems to have been said about this so far . Do you have any information? Regards,

Les Cooper

Nothing could be expected to change in MOT testing at present, as the MOT stations do not have equipment to investigate or conduct any tests on the emissions involved. I also very much doubt that they would be given listings of affected cars and given any authority or information to take any action if such cars had not been recalled and modified. I guess the question to which there is no answer as yet is: Will it affect my car’s performance and fuel economy? To which I cannot give an answer but, if I had to bet on it, I would say that probably no great effects will be noticeable. We don’t actually know yet whether the software in question is/was actually active on all UK cars, or merely lying dormant, waiting to be activated if the car were to be earmarked for the US market, for instance. But I’m only speculating. But your car is the same as it was last month, and nothing has changed in that sense. Skoda UK will (hopefully) keep you informed, and I imagine that consumer organisations will be making very sure that owners don’t come out of it worse off. At present though, we can only tell you what Volkswagen are making public, and that’s as far as we can be sure of our facts.

Then, some days later, I added:

As you may have read now, whilst the other TDI engines with the problems (1.2 TDI and  2.0 TDI) are apparently going to be sorted with software updates, it has been stated that the 1.6-litre TDI resolution may/will involve fitting new injectors (The resolution has now been changed by VW – Ed). I can’t as yet fathom out why this may be so, as the explanation given by the UK VW boss (he probably had his fingers rapped for even saying that much) was that the “defeat” device was related to air intake control. Knowing that NOx emissions control is linked to the EGR (exhaust gas recirculation) system, I suspect that some feature of the EGR regarding how much exhaust gas was recirculated is possibly “disarmed” at higher power outputs, and engine speeds not encountered during the EC test cycles, thereby permitting higher volumes of fresh intake air and resulting in higher NOx output. Why new injectors may be required to solve the problems with the 1.6 TDI engine may in some way be related to how the EGR system operates. As far as the injectors go, both 1.6 TDI and 2.0 TDI units use eight-nozzle piezo injectors, the only significant difference being higher injection pressure capability for the 2.0 TDI, and, one imagines, probably larger orifices for injection of more fuel. This doesn’t add much to the picture, but I am constantly digging around to find what facts I can. I’ll keep you updated if I discover anything significant. In the meantime, it seems that you may have to be very patient, as Skoda and the rest of the Volkswagen Group attempt to source very large numbers of new injectors. For that reason, I imagine that 1.6 TDI owners may be the last ones to get sorted. Sorry it’s not better news – but if none of this had been revealed you would be just motoring on happily (in ignorance) wouldn’t you? Best regards,


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