Who on here can help me with this....Ive put Vanos in the search box, buts theres so much info and variation and opinion on it!
I have a rattling noise which (I think) relates to one of two things, engine or clutch (I know, quite a broad area!)
Its a standard 325i (2007) manual, 102k miles
basically I get a rattling noise under acceleration, like the sound loose or rattling chain. Always seems to appear about 3.5-4k revs. Sometimes it disappears once the car is warm, sometimes not.
doesnt seem to affect the performance, just sounds awful. Doesnt seem to be any noticeable drop in performance, mpg slightly down.
I know little about engines!
So during my reading, Im being told that the Vanos unit is BMW's variation of VVT or VTEC, which makes me think that at roughly 4k revs, this will kick in, and therefore the noise has perhaps something to do with this.
there are suggestions to clean/change the selonoids, but I wouldnt expect them to make such a noise? or should I?
Ive had it with BMW, who were useless, and told me it was a catalytic convertor, which I replaced. and it didnt cure it. the 2nd time around they suggested that I had something rattling around in the air-con system. So Ive since ignored anything they had to offer. Ive had it with a trusted independant who suggested in could be something to do with the intake manifold - but would want the car 'for a few days' and that hasnt been possible time wise.
ive done a search through Y-tube as well, the cars/vids on there with vanos problems seem to be very rattly and noisy from the start, which mine is not!
other big issue with these early engines is the headbolts - could it be??
my other school of thought is that something is rattling about in the clutch/gearbox, but I cant feel the rattle through the gearbox/gearstick and when Ive had cars with other problems with gearboxes, its been very evident.
happy to read and listen to any suggestions, its starting to really irritate me!