Hugh Scott, N Ireland
PS: I’ve recently become an avid reader of DC, which is an excellent read for diesel owners.
This is a bit of a strange one Hugh! Do you think maybe it was happening occasionally before the cambelt change and camshaft work, or are you quite sure it was not previously evident? Why did it take two to three weeks to appear, one might wonder? Is there any suggestion of fuel starvation at any other time, like foot down hard on the level, at high speed? Such circumstances draw quite heavily on the fuel supply and I quite understand why you had suspicions of the fuel filter and had it replaced. I also concur with your suspicions of possible dirt in the fuel tank. My suspicions veer towards the MAF (mass air flow) unit, which can just get dirty, but not necessarily throw up a diagnostic fault. But some of the favourite faults for poor running with these CDTi engines are:
1 Clogged EGR (exhaust gas recirculation) valve;
2 The MAF;
3 The “swirl valves” in the inlet manifold, where the actuator rod can fail, or the whole inlet manifold system can, like the EGR valve, get clogged up, due to short runs and not enough hard exercise – a bit like our arteries do later in life!
4 There could be some obstruction or split in a high pressure turbocharger inlet pipe, but I think the symptoms would be more severe than you are describing.
Now, it doesn’t sound to me as if you are proposing DIY work, but rather that you would like some ideas before you go off spending more money at a garage and not getting a definitive solution. Before you do that, for the modest cost of a tenner or so, (and I do know that you’ve used another product already) buy a bottle of Millers Diesel Power Ecomax, put the recommended double dose of it in your next tankful of fuel, and go out and do a decent hard run. I get so many letters where similar problems are cured with such simple action (particularly if you use supermarket fuel, and don’t do regular long runs) when it can be any of several things – MAF, EGR, etc. If this doesn’t improve things, then go and find a diesel specialist who will deal with lots of cars that use the same engine, and see what they say. It’s probably nowhere near you, but I’ve had great reports of Scotts Garage in Dundonald, BT16 1QQ, and it might be worth a decent drive to visit them. I hope these suggestions are of some help.
Thanks for your kind words regarding Diesel Car, for which you can mostly thank our Editor, and now magazine owner, Ian Robertson. (And our first rate contributors and back-office team, too – Ed)