A Mini adventure, at maximum cost

That does not seem right, Scott. It’s worth trying to find out if others are having similar problems with the same model of car.

Cleaning of the dpf should be automatic provided that you are not doing a lot of town driving without periodically doing longer runs that allow a cleaning cycle to be completed. If you are following the advice provided with the car, you have a case for complaint. None of the diesel car owners I know has had a problem with their dpf, though a friend with a Land Rover that has covered 150k miles has recently had a problem with their erg valve.

I was slightly concerned when I bought a diesel car with a dpf since I cover only 8k miles per year but it will be 3 years old this summer and I have never seen a warning light to let me know to take it on a longer run.

Agreed. My Fabia 1.9 tdi is 9 years old and averaged 8000 mile per annum. It’s not had any problems with the dpf or gate. I’ve not bothered with replacing the ohc belt either. The German manufacturer of the belt states it’s guaranteed for the life of the engine. It’s only VAG that insist it must be changed. Does anyone know of anyone with a belt failure?

Except with ‘non-interference’ engines, a broken timing belt will result in major engine damage when the pistons hit the valves coming in the other direction. VAG are good at quoting a lifetime for timing belts and then issuing instructions that this should be done sooner.

Failure of a water pump driven by the timing belt can also cause catastrophic failure.

If you can inspect the condition of the belt and look for signs of deterioration, including cracking at the base of the teeth it may be safe to carry on using it.

I don’t know how many belts do break. With my last car the lifetime had been quoted as 80k and the figure was revised to 40k. I kept an eye on it and eventually had it replaced at 60k.

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Conversely, my Fiesta 1.0 ecoboost has in board cam belt that it guaranteed for the life of the engine. So it’s possible to do.

Your cam belt is lubricated with oil, like a timing chain. Presumably this combines the durability of a chain with the lack of noise and vibration of a belt. I’ve read that it should be inspected after 150k miles.

My experience with diesel cars (of only one make and model) with a dpf is that I cannot drive too gently (as one might to deliberately save fuel) or a warning light comes on after a few weeks and one has to regenerate the filter by immediately driving at high revs for ten minutes or so. Drive briskly on dual carriageways and motorways and the problem does not seem to arise.

I drive gently for various reasons and the warning light has not come on since I bought my car in July 2012. The instructions that came with the car say that I need to periodically drive at or above 40 mph for ten or fifteen minutes (I cannot remember which it is). I usually do this once a week anyway.

All new diesel-engined cars are fitted with a DPF. It is clear that they are unsuitable for those whose driving is mainly in built-up areas, unless periodic longer journeys are made.

My car dealer asked about my proposed use when I said I had a diesel car (without a DPF) and was interested in buying another diesel. He gave me a leaflet and another copy was provided as an insert in the manual.

What disappoints me is that I have no knowledge about the state of my DPF or when it is being regenerated. There are times when the fuel economy is about 10 mpg below normal, which I assume correspond to the use of extra fuel to burn off accumulated soot. Since DPF blockage is measured from the pressure differential across the filter, it would be easy to provide the driver with an indication of the percentage blockage. Understanding the process would be helpful to drivers and could help them avoid a blocked DPF.

I suspect you are right that some cars are more problematic than others. Furthermore, older engines that are starting to use oil could also have problems.

William You had a Mazda 6 2-litre diesel car? They are fiotted with Dual-mass Flywheels and they are seriously bad. The DMF is fitted to many cars, not just the Citroen/Peugot/Mazda group. I know that VAG, Jaguar, Ford and others also use them. They all have the same problem with early failure of the DMF.

The dealers try to blame the drivers for ‘riding the clutch’ causing the clutch plate glue to overheat, but expert examination usually finds that the bolts holding the two halves of the DMF together are weak and start to stretch. Eventually they become so stretched that they start to touch the bell housing making a racket and the starter motor has difficulty engaging the flywheel making starting difficult. Often this starts to show as early as 30,000 miles.

This is probably too late, but you should have had an expert independent engineer inspect the components to prove that the failure was the DMF, not the clutch. You were robbed by crooks of the motor trade.

I should have mentioned that you should search Google for ‘dual-mass flywheel failure’ for more enlightening information.

I wonder if some of the failures reflect the aggressive driving style of many motorists. In London in particular most drivers seem to alternate between brake and accelerator. It seems obvious to me that this is will be detrimental to the clutch, DMF and other components of the drive train. I doubt that it helps to get anyone to their destination any faster.

I found an interesting article on the HonestJohn website discussing the problems with Dual Mass Flywheels that includes a list of vehicles with reported known problems. There’s also a link to a LandRover owner who had the failure and tried to elicit some information (without success) from the German manufacturer of the DMF. It definitely looks like it is the DMF and has nothing to do with driving style.

http://www.honestjohn.co.uk/faq/dual-mass-flywheels/

I’m not so sure. Near the start of the article: “What seems to happen is excess temperature from drivers riding their clutches affects the compound.”

Yes, but it is a case of ‘seems’ rather than did ride the clutch.

There are plenty of other reports on the Internet. One interesting one because the guy had a failure on one car at 36,000 miles and he had a second car (his primary car) from new sitting on the drive with 130,000 miles on the clock. That suggests that he wasn’t guilty of riding his clutch.

It still suggests a poorly designed or poorly manufactured component.

An independent inspection would probably establish the reason for the failure. If a design fault can be established, that could help other owners.

My father taught me not to ride the clutch and gave me other useful advice on how to minimise wear and stress on the mechanical components. For most of his driving career he had no clutch problems.
In the last couple of years that he drove, he started to abuse the clutch, despite my warnings. It was no surprise that clutch had to be replaced after a much lower mileage than his previous cars had covered without problem.

So far I have followed my father’s teaching and have not had clutch or DMF problems. Only yesterday did I discover that my present car has a DMF and so did its predecessor, which I had for ten years. If I start to abuse the clutch, that will be the time to get an automatic or give up driving.

I have watched drivers slipping the clutch when crawling up hills in traffic. Sometimes you can smell the clutch overheating.

It would be very easy for a manufacturer to include a tell-tale to show the extent to which a clutch has been overheated, perhaps by incorporating pellets of alloys that melt at different temperatures. Alternatively, an over-temperature warning light could warn the driver that they are abusing the clutch.

Likewise in over 50 years of driving, I’ve never had a clutch (or flywheel) failure. If it really is a clutch abuse problem, the manufacturers could easily give a warning light. VAG provide warning lights for overheating of the DSG gearboxes (I’ve never seen that come on either), so these things are obviously possible.