Help!! Is my vanos unit messed up????

[m3f_GrkMf95M3]

I had the hood of my car up today and gave it some gas from where the throttle was. It seemed like there was a weird noise that i have never heard coming from where the vanos unit is. It sounded fine as the rmps dropped but at a certain lower rpm there was a point where it sounded like there was a farting noise from where my vanos is :fart:. Does anyone know what this noise is? The noise of the engine was fine, until the rmps dropped to a certain lower rmp and this grunnnggg grunggggg noise would happen. I dont know if some of the engine covers were loose or something to make that noise, but it was at a destinct lower rpm and sounded like it was from the vanos unit.



Also, i dont know why, but my car has its good days and bad days. Sometimes it seems fast as hell and other days it is kinda slow. Suprisingly it has been running very strong the last couple of days so whatever is going on in there isn't slowing me down. Do you guys know if my vanos is messed up? or if this is something totally different.



Thanks

[m3f_Sirius_880bd69485]

Well, everyones car has good/bad days, mine does too. Some days it just seems to run better. I blame that on mood and atmosphereic conditions... maybe something to do with the pressure. Not personally fimilar with the noise though...

[m3f_Flybry07_aa2e46014a]

It sounded fine as the rmps dropped but at a certain lower rpm there was a point where it sounded like there was a farting noise from where my vanos is :fart:. Does anyone know what this noise is? The noise of the engine was fine, until the rmps dropped to a certain lower rmp and this grunnnggg grunggggg noise would happen.





Some "marble rattle" type noises and gargling noises are very normal. It is simply the tolerances between the helical gears in the vanos unit that is causing thoes noises.

Espicially in the lower rpms (close to idle) when the vanos unit is de- energized.



Now if thoes noises are abnormally loud and you are hearing them even with the hood closed while driving than thats a different story!!



What rpms exactly are you hearing the noise??

[m3f_GrkMf95M3]

i'm not exactly sure what the rmps were. I was in front of the car when i would push on the throttle from the engine bay. It was the lower rpms, maybe around 1500, 2000 rpms i'm guessing??? not exactly sure though

[m3f_Drifter_23d8df4bc6]

Same thing happen to me. but I got that problem from driving it hard with 1 to 2 quarts low. then 800 bucks later i had a rebuilt vanos.

[m3f_Flybry07_aa2e46014a]

No cause for alarm I dont think, sounds pretty normal.



My buddy has a 99 like mine with almost 100,000 miles on it and it has been making that gargling noise since he bought it almost new (had about 30k)

3 years ago.