Forums Forums Enthusiast Forums A - Z Autowirral Diesel Particulate Filter - New MOT Regulations

I think the problem of diesels is a combination of heavy sales patter and a lack of knowledge passed down from parents.

When I was a kid my dad told me that diesels were really only for distance driving, and they were dirty and smelly.

Things have changed, they're much easier to live with and run. My diesel purrs like a kitten and you can't even feel the engine when its stood at traffic lights.

But then they started to make small engines (I think you can get a 1.1 diesel now) and put them in small cars and tempted people with £30 or £20 or even £0 road tax and the great MPG figures.

I once had a Fiat Punto 1.3 diesel. Brilliant car, lots of power and cheap tax. It had one former owner, full service history and under 30,000 miles on the clock.

But after a while it started to play up. I took off the EGR valve and it was completely full of crud. It looked like it had done 90,000 miles (I've had a few old diesel Peugeot 306s with high mileage so I had experience in that field).

The former owner, a Wigan woman, used it to just pootle around town in, she never went on the motorway and Wigan isn't blessed with fast dual carriageways.

A good clean and a new MAF and all was well again. But that won't help people who have new cars with DPFs as standard or don't like to get their hands dirty.

And once the problems do start and the car is out of warranty, these are going to be someone else's problem in the second hand car market.

I've already seen a marked drop in value of 110bhp Peugeot 307s (with DPF) as opposed to the 90bhp (non DPF) models which are commanding a good price.

BBC Watchdog did a feature on it. Its not on iPlayer but if you Google "BBC Watchdog DPF" you'll find plenty of links relating to it.

I got my car, a Mazda 6, with a book value of £4500, for £1500 with a blocked DPF. With a new DPF supplied and fitted costing about £2000 the car was pretty much a write off. DPF Removal for £500 and it's as good as new. BMW DPF's also cost £1500 upwards.

If the exhaust is taken off and the filter removed from the top, and then rewelded then no-one will be any the wiser. ECU's also need reprogramming as the pressure sensors will throw up errors.

My brother has a company specialising in DPF's, He removes and cleans. This involves a DPF kiln and Suction.

It started getting blocked occasionally and the light would come on. About 10 mins up the motorway at around 2800 revs would clear it. It got to the point where it happened every day until it would not clear at all. After 2 days it went into limp mode. The garage did a forced regeneration to clear it plus the boost pressure sensor had failed too. I don't know if one fault caused the other but it cost the best part of a grand in the end. It has been fine since. This was about 6 months ago.

Who quoted £2000 though? I've seen them as low as £200 and as much as £450 on Cats2U for a Mazda 6.