Originally Posted by KUSH
Hi I have ordered the disa 1 the part has been revised three times. Cleaning the vanos solenoids & switching them makes a big difference & I believe it helps cause carbon build up on the vanos system & will cause it to throw vanos & solenoid codes. As far as symptoms the car still idles perfectly but flat spots on low rev acceleration from time to time as the fault is a jamming vanos. I am waiting for my disa 1 to arrive from the us they made a mistake with my order so i have had to re order it. Should arrive in the next couple of weeks. Will keep you informed of the results
I have often heard about cleaning vanos solenoids but never done this or investigated yet since the car has just come off motorplan. How easy is this to do, access? Will search of course.
My 330i's symptoms are similar in retrospect, except there are apparently no codes coming up at all - so according to the agents everything is fine and "normal", which it isn't!
To be exact, my main annoyance has always been a rattling noise at certain low engine speeds only when under acceleration/load and sometimes on the top of a gear change. At first I thought this was a dual mass flywheel chatter, then the agents diagnosed it as pinging - updated software, reset adaptation and tightened an exhaust bracket. No difference at all, and now off motorplan. Replaced spark plugs (still 35k km life remaining) and also ran a tank with Liqui Moly Injector Cleaner - still no improvement. Now coupled with this noise I have become more aware of other issues (more annoying issues), and this is definitely also flat spots and jerkiness at low revs, plus often there is a distinct drop in performance between 3000 rpm and around 4500 rpm (intermittent).
I took the car to a local highly regarded tuning specialist and their diagnostics which takes almost a full day to run picked up a few issues. On the live reading while on the road they picked up that the engine was being forced to run too cold indicating that the thermostat is not regulating temperatures properly. They said that the valvetronic motor is out of spec by 10% which can be corrected with software (recalibrated I imagine). But, they claim that the noise that I am hearing is from one or both of the DISA flaps fluttering and/or trying to make constant adjustment.
Supplying all of this information to the agents they are adamant that there is nothing wrong with these items - now I know (under confidence) that they cannot perform live diagnostics while driving cars, so it is very likely that they are simply plugging their system in and not finding any stored codes. The thermostat is not broken, it is working, just not correctly, and so are the DISA flaps and valvetronic according to the tuner. Oh, and the tuner is 100% sure that the engine is not pinging at all - of course the agents are too willing to point the blame at local fuel (95 unleaded) and say things like, the 320i's are even worse, or the automatic 330i's are also worse...
Sorry about the long post, but trying to convey as much info across as possible to see how close our car's issues are related. Based on the tuner's assessment it was indicated that I should replace both DISA motors, the thermostat and then see how it goes. The valvetronic recalibrated otherwise also something to replace (costs roughly the same as one of the DISA motors) - in that case also inspect/replace the valvetronic sensor also referred to as the eccentric shaft sensor which is located just behind the vanos on top of the engine (there is a plug visible where this is situated). Apparently a shot valvetronic sensor is usually the cause for erratic idling.
If you have a few minutes, took this vid a few weeks ago from my dashboard while driving my car. Of course typically it was behaving that day, but it was making the noise which sadly is never picked up with the simple GoPro's built-in mic. But you can hear at around 4800 rpm or so the engine note changes slightly up until red line, which confirms the stage change over from the DISA flaps - often the between 3000 rpm to 4500 rpm is very noticeable and in particular the way the car suddenly picks up speed from 4500 rpm and 4800 rpm onwards!