A friend of mine with a Citroën C-Crosser has been suffering very badly with the car going into limp home mode. When he telephoned his dealer, they said it was very likely that winter grade diesel was causing the problem and, sure enough when he took it in, they had to clean the oil lines and change the fuel filter. They said that it was a common problem with winter diesel, caused by the fuel forming globules, and recommended that he change the fuel filter every three years. The car has covered around 32,000 miles. I have a Peugeot 4007 (which as you know is much the same car) and it has covered 74,000 miles without any such fuel problems. I also have links with a firm which has a mix of seven Citroëns and Peugeots, which between them have covered around 600,000 miles, and as far as I am aware none of them has ever suffered in this way. Could it be that the fuel viscosity/winter additive differs considerably between filling stations? My friend normally goes to Tesco, whereas I go to Sainsbury’s or Morrison’s. (What do your food shopping habits have to do with all this? Doc.) Also, I thought the whole point of winter diesel was to avoid “waxing” which I guess is pretty much the same thing! Your advice please Doc.
John Austin

I’m not entirely convinced about the winter diesel causing the C-Crosser problems, I have to say. A blocked fuel filter maybe, but possibly merely an accumulation of muck, not true cold weather waxing, me thinks. Clean the oil lines??? Fuel lines??? How would they clean them? Maybe they purged them by somehow operating the lift pump to bleed the system up to the filter – I doubt that there’s any hand pump to prime the fuel line, as there often was in days of yore! I foolishly ran a Mercedes 8-14 7.5 tonne truck’s fuel tank bone dry on the M60 south of Manchester once! I managed to get a fast driving man in a Reliant Robin (what a terrifying ride!) to give me a lift to a filling station, found my way back, put some fuel in the tank, tipped the whole cab unit forward on its hinges, and re-primed the fuel lines! All at the roadside – and all in a day’s work then! You should feel the steering effort on something like that, when the engine dies and power assistance totally goes! Superman would struggle to drive something like that, and you can experience it for maybe 50 to 100 yards, when the engine cuts out!

But, back to the C-Crosser and your 4007, and winter diesel. Did we not cover this issue recently – issue 333? I’m pretty confident that bulk fuel delivered to regional depots from refineries, well before it has any additive packs stirred in, is where the seasonal change takes place, so it should not really be something brand-dependent. But it certainly could be engine-dependent. Thanks for the information though – I’ll ask my friend with a C-Crosser if he’s had anything like this. He does a lot of towing, and works his engine pretty hard, but it seems to be a very robust unit and he’s had no real problems to date, with 75,000 miles approaching – just that motorised throttle unit failure that I wrote about some while back. Later report – no such filter problems. All for now John. Keep taking the pills! Best regards,
Doc Diesel