DPF- Hope i have the abbreviation correct....

sistafromanothermista

Hi all.
I've recently purchased a used '09 plate diesel and i have read (on here) that to 're-charge' the filter i need to travel at over 3000 revs.
The question i have is this, even at 80 mph (done once to test) the revs are only at 2600 ish (hard to tell)
If i drop down to 4th on the motorway(doing 50 ish) the car doesn't seem to like it much and i guess this is really bad for fuel economy?
Any help much appreciated.

Gloomendoom

Does it have a DPF?

Just drive it normally. If it does, unless you just do short trips, you shouldn't have any issues.

RichardD1970

What does it say in the handbook?

jobdone1

Whats the millage try your egr valve my be full of gunk

Retrogamer

jobdone1 wrote: »

Whats the millage try your egr valve my be full of gunk

Try the EGR valve for what?

patman99

If you have a 'B&M' bargains store near to you, they do a fuel-based cleaner that you add to your tank. It will dissolve all the carp in your EGR and over a period of time you will find your car will run better & better.

My friend uses it in his Picasso 1.6 HDI & has noticed a marked increase in performance.

If you tell us the make/model of vehicle, we can tell you if it has a DPF & if there is a blanking kit available for the EGR (blanking this off increases MPG by up to 3%).

OddballJamie

What is the car and engine size? You may not have a DPF.

jobdone1

sorry mis read your post

Ultrasonic

sistafromanothermista wrote: »

The question i have is this, even at 80 mph (done once to test) the revs are only at 2600 ish (hard to tell)

Sounds normal. In my diesel I'd have to be doing about 90 mph in top gear to reach 3,000 rpm. It is perfectly normal to carry out the sort of DPF regen. you are talking about in lower gears.

If i drop down to 4th on the motorway(doing 50 ish) the car doesn't seem to like it much and i guess this is really bad for fuel economy?

What do you mean by 'doesn't seem to like it much'? Is it simply that you aren't used to driving at such high revs? Or that when you drop down into fourth you aren't pushing the accelerator enough to get the revs up before putting it into the gear (so that you feel a bit of a jolt as the car slows down, before you push the accelerator and you get the revs back up)?

This is definitely bad for fuel economy, but the cost of repairing/replacing a DPF would dwarf the cost of this.

But first of all find out if you definitely have a DPF. Also check what the manual for your car says.

GolfBravo

sistafromanothermista wrote: »

Hi all.
I've recently purchased a used '09 plate diesel and i have read (on here) that to 're-charge' the filter i need to travel at over 3000 revs.
The question i have is this, even at 80 mph (done once to test) the revs are only at 2600 ish (hard to tell)

It is a myth that you need to drive above 3000rpm for the DPF to regenerate. Increasing the revs too much actually prolongs the regeneration process unnecessarily.

DPF regeneration is fully automatic, and it relies on exhaust gas temperature and not on increased exhaust gas flow. The car's ECU decides when to start the regeneration process, and it changes some fuel mixture parameters to increase the exhaust temperature. You can help it by increasing the engine load, not revs, by putting it in high gear and giving it some berries at low revs - don't need to keep it above 3000rpm, normal revs will do (around 2000 is fine).

But firstly you need to know when the regeneration process is triggered - not an easy job unless you know your car well (different engine sound, sluggish or extra zippy, ticking rear window demister relay, smelly exhaust fumes, may feel like misfiring under acceleration, etc. varies between brands).

Unless you get a warning light or message on your dash (e.g.. particle filter blockage risk) don't worry about it. Just give your car a chance to regenerate by driving it (sitting in traffic jams doesn't count) for at least 20 minutes from time to time.

OddballJamie

It's not a myth, it's in the manual of some manufacturers. If you only do short trips with a diesel fitted with a DPF then forced regen is something to have to do and live with. I ditched mine in favour of petrol and haven't looked back.