Meeko said:
Hi Andy,
Are you considering the VANOS as a possible cause becuause your new ICV didn't cute the hesitation/flat spot?
I'm keen to et mine sorted and it's under BMW warranty so will guide them towards the cause when it goes in.
Thanks,
Steve
Ah yes sorry I didn't update the last post. Basically it didn't cure it, the ICV movement was slightly different between old and new but alas it made no difference on mine.
For a relatively small problem I don't want to throw too much money at it, end of the day car drives fine, its just a niggle which annoys me to be honest now I know its there!
I've checked the car quite thoroughly on INPA, no fault codes, software is up to date, and all the sensors are giving readings within tolerance, nothing that looks to be a cause for concern.
The only thing that is out of tolerance is the 'VANOS Einlass' and 'VANOS Einlass Sollwert' readings. Translated as 'VANOS Inlet' and VANOS Inlet Set Point'. See pic below:
Now this could be nothing major, but its out of tolerance whatever it is. The strange thing about INPA and our cars is you can't run the VANOS TEST function in INPA that you can on M3's, which is really annoying. Apparently a new version of INPA is out shortly which may fix this although I'm not convinced as our cars are quite old now and probably not on the top of BMW's list for re-coding.
This is going to be the last 'fix' I attempt on the car as I don't think its an issue that really warrants a lot of money being thrown at it, its just not worth it. It is a totally liveable 'quirk' and doesn't effect day to day driving or the overall power of the car.
I feel the overhaul of the VANOS though is worth doing as reading up on M3 forums everyone who has done this has reported very good results. It also strengthens an area of the engine I believe is not fit for purpose as such in the first place with oil seals which will harden over time and essentially 'fail' gradually, something that wont throw an error code either. The next owner can also be safe in the knowledge that the VANOS has been strengthened so will hopefully help my re-sale when I decide to pass on the car, hopefully not for a while yet! So the benefits are many in my eyes. Expensive, but piece of mind.
This is what Beisan say on their website about the symptoms of failing VANOS seals:
Vanos Seals Failure Symptoms
Overall loss of torque and power, particularly in the lower RPM range, < 3k. Bogging then surging at 3k RPM. Uneven power distribution and RPM transition. Engine hesitations in the lower RPM range, < 3k. Louder idle and intermittent idle RPM hiccups. Difficult takeoffs. Loss of power and bogging when AC on. Increased fuel consumption. Vanos fault codes.
Double vanos cars with the M52TU engine (98/99-00) experience cold weather cold start idle jolts and possible stall.
Some of those certainly sound familiar!
My car's booked in at Redish Motorsport for the procedure so I'll report back when its done. Its not till mid December unfortunately though so a while off yet.
*shibby* As you rightly say a failed/failing solenoid would throw an error code most likely so I wont be replacing that part. By the way did you used to be on the MR2 IMOC forum?? Remember your username from many moons ago!
