Anzafin

Thanks mate.

I understand the assumed relation between the removed swirl flaps and clogging of the DPF, and it may have its part in this, but I don't think it would be in a main role at all. This is what a WDS says about swirl flaps if they remain open all the time (or have been removed of course -> same effect):

"If the swirl flaps stick in open position: Deterioration in exhaust gas characteristics in lower speed ranges otherwise no effect."

Whatever their influence is on clogging, I still believe it's minor compared to the fact that my car hasn't done the DPF self cleaning burn for couple of months (until yesterday )! Besides, I still like them removed rather than waiting for the day they would be sucked into the engine and cause the end of the world of mine !

- Antti -

edit: One more fact about the swirl flaps!

The WDS tells that swirl flaps remain open if the intake temperature is lower than 15°C.
So.... If I had them, they still would have been opened over the whole winter!! Actually they would stay open the most of time up here haha!

E60-530d

Got my DPF problem fixed by opting for a DPF-delete without any changes to the exhaust pipe. The DPF was removed from the car and the inside contents of the container/can were physically removed. The empty can was reattached and then a software code-out was performed to make the car think it never had a DPF (like the early E60s in 2003 which came without a DPF and a downward facing exhaust pipe). No error codes and/or warnings were seen after this coding out was completed.

The end result of the above is that I can drive my car again! Gone is the terrible limp mode and the dangerously high back pressure. I considered various other options available to me before going ahead with this particular way forward to sort this out.

A forced regeneration and/or a DPF wash/clean would probably have sorted it out but only for the short term. With plenty of slow short journeys and lack of longish motorway use, the DPF would have got blocked again sooner or later (especially with an extra cold winter like we had recently). Another option was completely removing the DPF and replacing with a new/modified pipe + code out. I also considered a brand new DPF fitted by my $tealer. Apart from the stupid cost involved in going with this option, I considered this to be a similar option to a forced regen or wash/clean. My journeys would have caused premature failure of the new DPF ! So now DPF free, I just excercise good habits by allowing some warm up time before any enthusiastic driving and allow the turbo 30 to 60 seconds before switiching the engine off. There are 2 things that I have noticed following the DPF delete.

The first is possibly more noticable in my particular case as I have manual transmission. When lifting off the throttle quickly, I can hear a short, quick "WOOH" sound. This is more obvious when lifting off to change from 2nd to 3rd and from 3rd to 4th. If I drive slowly and change up without trying to drive fast/pushing it, then its not really there. I can also hear it if I push the throttle down and lift off quickly while driving steadily in for eg. in 3rd. At first I thought it sounded like a dump valve or wastegate sound but I guess its an accentuated turbo whistle/sound. I don't think I can do anything about this WOOH sound (or can I ??). It doesn't really bother me (especially with the stereo on loud !!) but I know it wasn't there before DPF delete. I do wonder what would have happened to this sound if I'd gone with a new/modified pipe rather than keeping the empty DPF-can as part of the exhaust system.

The other thing is a little more smoke. But its not visible in normal driving or even when pushing it hard but I certainly see it in the rear mirror when crawling in traffic for a good few minutes and then suddenly going for it. Is this unburnt diesel after the crawling pace? My impression is that this extra smoke when flooring it following a crawl is normal especially in older (pre DPF) diesels. All other aspects of the car are fine such as mpg & power.

So now that I am DPF and Swirl Flap free, should I worry about anything else ? Was thinking of a remap but don't really want to risk anything after all my DPF blues! Who knows....Remap + No DPF = maybe more smoke. Any clues about the WOOH sound?

ya5

Hi mate .. where did you get the dpf delete coding done from ?? as Ive had same problem in past but have cleaned the dpf .. but want it removed completely ...

E60-530d

PM sent

Anzafin

It could be the MAF indeed. Get it checked.