dpf

[bryan13]

can anyone tell me what triggers the dpfs to start a clean up cycle

[J44EAG]

Hello Bryan,

As I understand it, DPF regeneration is triggered when the Powertrain Control Module senses the filter is becoming blocked and needs a burn out. A good blast on the motorway can often allow the process the complete the regeneration cycle. The biggest cause of blockage is using a diesel car equipped with DPF car for short travel cycles. If a regeneration begins to take place and the cycle cannot complete on short journeys, the filter continues to be blocked and the PCM continues to allow an extra injector used for DFP regeneration to keep feeding excess fuel into the filter. Finally the light comes on and a forced regeneration must be carried out at a suitably equipped garage. It is not unusual to find the engine oil level rises as a result of this continued overfueling. That is not good. It is well known that diesel fuel diluted oil is frequently the cause of engine failure caused by crank big end and main bearings becoming excessively worn due to the break down of the diluted engine oil.

DPF filetr issues need immediate attention when they occur. Two links for you to look at.

http://www.google.co.uk/url?sa=t&rct=j& ... GU&cad=rja

http://www.google.co.uk/url?sa=t&rct=j& ... GU&cad=rja

Google, Jaguar DPF regeneration or similar wording to find out more about the system.

There several "add to tank" products that can assist the process and help maintain a DPF in good condition. Halfords stock DPF cleaner and ebay and similar sources may also provide.

Other diesel model owners using this Bulletin Board may also be able to advise on the process.

Hope that helps.

Mike

Mike

[bryan13]

that's great info thanks mike not a problem with mine as I commute on the motorway to work, i have come off the motorway to find the tick over erratic and plenty of heat when you open the door to get out so i guessed it was running a cycle just wish they had fitted a light to let me know when it was running a cycle so i could take steps to let it finish before stopping.

[jeff1954]

Hi Guys
Fortunately my car is a 2004 pre-DPF (Thank god as I do a lot of short journey work) In one of my other post's on the forum I asked if there was a way to kid the cruise control to enable fast idle when stationary, Judging by the the lack of response I don't think it's possible. But if you could achieve this it could be a way for people with DPF engines to simply let there engines get hot whilst sat in the garage (door open) or on the drive instead of driving round to get the engine hot to enable regeneration cycle. Just a thought.

Jeff

[J44EAG]

Not really a good warm up regime. An engine needs to be got up to temperature as quickly as possible firstly to avoid excess pollution but to minimise the effect of fuel wash on cylinder walls and piston rings. The longer over fueling occurs during warm up, the greater the wear on reciprocating components. Oil dilution is also an issue as the excess fuel finds its way past piston rings and dilutes the oil which affects its structure and in extreme situations can cause massive bearing wear and ultimately failure. If that occurs, you will need a new engine!

The worst ting that can ever occur to an engine is a warm up at idle on the drive. It takes around thirty miles of driving to "burn off" the effects of each and every cold start. Cars used for short journeys and that never get fully hot need more frequent oil changes to keep oil quality up to the required protection levels.

I agree you are fortunate not to have DPF units on your car. The issues surrounding DPF management and rectification frighten the living daylights out of me. These modern diesels thrive on high mileage use but can be very problematical if used for short journey work.

Mike