First mot failed emissions
 

My 3 years old v70 d2 1.6 diesel failed its first mot on emissions.having 8500 miles on the clock, took it to volvo main dealer at chigwell.they had it for 4 weeks and at that time decided it needed a new dpf, which included several tests a service mot. and cost nearly £900.

That must be annoying - was that covered under warranty?

What it probably needed was a good Italian Tune up - a good run on the motorway. Many "gently driven" diesels do accumulate loose soot in the DPF and exhaust system which gets belched out on the fast run exhaust opacity test. The best way to sort this is take the car for a nice run in the country and include five or more brisk acceleration runs to 70 mph or so taking the car to the red line in 2nd and 3rd gear at about 70% throttle. Quite often the first time you do this you get a plume of black smoke, but it gradually clears.

A well maintained diesel does not need a DPF to achieve MOT compliant exhaust emissions (but removal of the DPF will fail the MOT). My 2003 XC90 D5 and 2007 V50 2.0D generally achieve a reading i.r.o. 10-15% of the limit and neither have DPF (both are north of 160k miles).

Interesting, surely a warranty issue? The test is quite lax on diesels, only for smoke, so a good bash before taking it in should help.
http://www.ukmot.com/MOT%20test/Emis...-%20Diesel.asp

I'm not sure that 8500 miles over three years is that good for a diesel engine. As already stated a good thrash before an MOT is well worth the effort and maybe one of the injector cleaning products in the tank for a few weeks beforehand.
I have only ever changed a DPF at 75000; not due to any issues but that's when the schedule recommended it.

If you want your wallet felt, take a car that is out of warranty to a dealer for an MOT.

Before an emissions test it's a good idea to use a major brand direct feed injection system cleaner or run it for some time on a top of the range fuel additive. I use Liqui Moly Diesel Purge to fill up the fuel filter housing when replacing the element. That should clean out any gum from the injectors.

It also helps to give the engine a real good run on the motorway, or do an Italian tune up to burn out the Carbon deposits.

Just out of warranty, Volvo agreed to pay 80% of some of the costs if i agreed to have a full service, felt like i was sort of blackmailed into doing it.

I suspect that was because they knew you wouldn’t be back again so they were determined to have a slice of your wallet.

FYI the DPF has no effect on how much smoke the engine produces, it’s just meant to filter some of it out. obviously I didn’t see the car but I expect the smoke could have been reduced by a couple of forced regents.

I am an MOT tester & see many diesels for test ( obviously ! ) that now struggle to meet required smoke emission limits . When i speak to owners / presenters , I usually find the vehicle has been driven around town at low speeds / short journeys . This allows the build up of soot on DPF element , leading to blocking / the need for forced re-gen of the DPF Etc .

I often advise owners to use our local motorway (M55 ) with the addition of injector cleaner in the tank , driven at 70 mph using a lower gear to raise rev's used .

This increases gas flow , blowing loose soot away & increased heat to perform regen as required . I strongly reccomend any customer owning a newer diesel to perform a getaway driver tune up before arriving to have their car tested & also make sure it is as hot as possible .

So , I apologise to any Fylde coast residents smothered in soot as they use the M55 to get to Preston & back , doing my bit to keep your money out of stealer ships pockets & ensure your car passes it's test

Sound advice - good man.

I too was going to say "Italian tune-up". There, Ive said it.
A proper drive somewhere to get up to temp, 1/2 hour plus, then a damn good thrashing what ho !
If the police pull you over tell them that the judge would approve, and you know the chief constable likes that sort of thing too.