checksum

Hi All,

I have been experiencing a strange intermittent problem with my E61 525d, occasionally on a normal run to work the engine seems sluggish through the lower rev range and seems lumpy to accelerate, the engine note also changes to more of a drone almost like its being choaked.

Then the next day its back to normal.

Any ideas?

Cheers

Checksum

checksum

I think I may have found the culpret in another forum, It appears that peridically the Diesel Particale Filter (DPF) goes into a cleaning mode which can take upto 20 minutes to complete.

If the cycle is interupted and does not complete the computer shedules another cleaning process when the system reaches a operational temperature and starts again.

I think it keeps happening to me as my normal work run is quite short so it keeps getting cancelled and has to start again.

"Regeneration of the particle filter DDE7
The software applications of the engine control units since DDE5 always co-ordinate the management of particle filter regeneration. This means that, in principle and without the driver having to take any action, the system is able to ensure optimised regeneration operation over the entire utilisation phase of the engine. In individual cases (e.g. customer complaints), a service regeneration can be requested in the workshop. To enable service regeneration of the particle filter, regeneration must be requested in the DDE control unit. This is requested using this service function.
The regeneration is requested in that the consumed fuel since the last regeneration is set to a maximum value in the DDE control unit.
The regeneration is started at the next trip as soon as the coolant temperature has reached a value of at least 75 ?C and the exhaust-gas temperature before cat. has reached a value of at least 240 ?C. Moreover, the fuel level must be at least 10 litres.
The best possible effect of the regeneration is achieved if the vehicle is operated for around 20 minutes at a speed of at least 60 kph that is as constant as possible as of the start of the regeneration. Experience has shown that non-urban driving achieves the best regeneration results.
The current state of any regeneration block, of a regeneration request in the control unit and the regeneration itself can be displayed both in the service function ?Regeneration of particle filter? and in the DDE diagnosis request at the point ?Regeneration particle filter?. Moreover, the distance driven since the last regeneration can be read out.
The following possible states on regeneration are displayed:
? Regeneration blocked
? Regeneration released
? Regeneration in DDE requested
? Regeneration not requested
The following possible statuses of the regeneration are displayed:
? Regeneration active
? Regeneration not active
? Distance driven since (last successful) regeneration in metres
? Calculated total distance driven with the particle filter in kilometres.
? Average fuel consumption per 100 km since filter replacement.
Notes:
In the event of a prematurely cancelled regeneration, the regeneration is started in the next drive cycle as soon as the coolant temperature has returned to a value of 75 ?C and the exhaust-gas temperature before cat. has returned to a value of 240 ?C.
In the case of a particle filter heavily loaded with soot, it can occur that the regeneration request is blocked again after a short time or is not released.
In this case, it is required to regenerate the particle filter in a motorway / or cross-country trip taking approx. 30 minutes at a speed that is a constant as possible.
Subsequently, the service function ?Regeneration particle filter? must be run again.
Moreover, it also occurs that with a particle filter heavily soiled with soot the exhaust-gas back-pressure becomes so high that problems can occur on reaching breakaway speed. In many cases, this impairs the feasibility of the exhaust backpressure test. A clean regeneration reduces the effect of this problem in many cases and lowers the exhaust-gas back-pressure.
During the regeneration phase and with the engine running, it can also occur that the display for 'Regeneration active' jumps to 'Regeneration not active'. This behaviour can be seen exclusively with the vehicle stationary with the engine running. This behaviour does not impair the scheduled course of the regeneration in general."

Quoted from from: http://www.bmwland.co.uk/talker/viewtopic....asc&start=0

mmitev

I had noticed the same behaviour of my car and was a bit worried until I found the reason elsewhere in this forum. But the infos you've quoted are so detailed that it does not make sense to search for the other topic.

Just not sure what do they mean with this display message "regeneration running" - I haven't noticed anything on my display, it seems the OP hasn't either. My car is from 09/2004. Has anyone else seen an iDrive message on this process? Maybe in LCI cars?

checksum

I have not seen anything on the display either but for the moment I have set the display to only view the DPF in the service menu, Currently all it says is 60000 miles OK.

I'm guessing when the car goes into DPF regeneration mode it will be displayed in the status messages.

I will report back if it appears.

xBMWx

Sounds like the DPF to me. Even though I know what it sounds like, it still worries the hell out of me everytime it does it... and then its window down, lean head out of window to hear exhaust, look for smoke, then eventually conclude it must have been the DPF again

mmitev

the first time it happened to me I stopped at a gas station, windows down, stopped the engine, then started it again, revved up a few times, switched the gearbox back and forth (I thought the burbling sound might be a vibration due to a problem in the gearbox), revved up again, stopped, started.... people must have thought I am totally crazy...

flyingpuck

Lumpy??

checksum

On the way home last night the DPF regeneration kicked in, slight engine note change with high pitched whine, lumpy (sluggish) low revs and booming exhaust sound. (e.g sounds like the exhaust is being blocked)

I decided to drive a bit further to pass the 30 minute max DPF regeneration cycle keeping my speed above 60kph where possible and it worked, although nothing was shown in the display under service menu to state it was actually occurring.

I drove back to my house and all seems fine again.. I think BMW should inform people of this as it is quite disconcerting when it happens.

rjc

There is no display of any kind as the DPF regenerates. Discounting the 'rough' running and holding the revs more (so it sounds louder). You will also get a smell from the exhaust when it gets going.

I have noticed that with the likes of BP Ultimate the DPF doesn't seem to regenerate as much (I have 42k on mine since new), which I hope may pro-long its life - they cost a packet to replace. It doesn't appear on the service settings as an item, last time it was in they showed me the stuff stored on the key and it wasn't there either. Be nice to know when it thinks it needs replacing, I guess this will need the diag computer to read that out? If so, I may ask as it will be in soon for an oil change.

Nice to see another Cambridge person about too.

juliann

Does appear in my service menu, but I have an 05 - 35d. When new, it showed 120,000 miles and counted down to zero after about 125,000.
(Still not changed it to no adverse effect after 175,000m but may take it off and have a look at it soon - would be good to know the std weight of a new unit so I can weigh mine and see how much cr@p is in it)

J
(previously of Duxford & Whittlesford )