There has been afew threads and postings recently about swirl flaps and the deterioration of them.
Alittle back ground :
My cars a 2007 335d E92 coupe, built on 24th April
Purchased it with 30,000 miles
Current mileage is circa 112,700 miles
I've had the car 2.5 years
At 30,000, the day of purchase I added my DTUK CRD-t tuning box, returning 340 bhp and 510 lbs/ft
Since purchase I have only ever ran my car on Shell V-Power (99% of the time) with the odd tank of BP Ultimate diesel.
I use my car daily, I drive it fairly hard most of the time, but I maintain it meticulously, either with genuine parts or uprated versions of.
I do a mixture of distance and town driving - the odd long trip, but mainly A roads and about 15 miles of A1, the rest is city and town based driving, the car in winter idles allot as I work out of it and like to keep warm lol
As my car approached 100,000 I became weary about the build up of carbon ect due to age/component wear ect....
I decided to remove my EGR (never been a fan of EGR ever) and my car developed a slight oil leak.
I stripped it down (inlet and EGR) - I found that the swirl flaps, three of them, had weeping oil seals.
I replaced them with swirl flap blanks.
I inspected them on removal - as I expected, the oil seals were causing the oil leak, but I noticed one of them had deterioration on the centre section of the flap.
Below, deteriorated rubber section of flap
Below, all 6 flaps and EGR
Below, flap removal blanks and cleaned inlet
These was a lot of oil and dirt that had accumulated, so it looks like they'd been failing for some time/miles.
I looked at the carbon build up too, I was pleasantly shocked/surprised by what I found !
The carbon build up was minimalistic to say the least !
Having had and run several diesel engined vehicles for afew years and tuned them all, I was expecting carbon and gunge everywhere !
This is what I found:
There is less than 1mm tall of carbon deposits - EGR functioning perfectly and quite clean all round
I can only attribute this to the quality of fuel and keeping the vehicle well maintained.
On a side note, I've never seen a DPF light or had any issues with it, I've recently had it inspected (BMW master tech) and the service light rest for it.
It's functioning faultlessly too - no smoke, clean as a whistle inside the exhaust.
Just a (semi) interesting / informative post .... Maybe ....