Talk to me about Vanos

ver328i

Well-known member
Hi Guys

So my car is on the road again :=):

Had the head done, port matched, valve stem seals etc. Did the timing and installed vanos according to the bentley manual. She fired up first time and actually idles so much quieter than before...although:

I can now feel vanos come on at 3500 RPMs. Is this normal? it seems as if theres power from zero rpm but around 2500 Rpms there's a flat spot and at 3500, VTEC!!!(lol) she pulls strong all the way to the limiter.

how is vanos suppose to feel? My car always had a smooth power band but didn't pull as hard as it does now so im not sure whether Its right or not.
 

danieljames

Active member
I'm assuming that's it's an m52....Therefore there's vanos on intake and exhaust unlike the m50 with single vanos. From my experience driving an s52 they are exceptionally linear in power delivery. On My car on the otherhand I can feel the kick as the vanos shifts. So my 2c is that it should feel very smooth. Although I don't own an m52


Glad she's on the road.
 

ver328i

Well-known member
danieljames said:
I'm assuming that's it's an m52....Therefore there's vanos on intake and exhaust unlike the m50 with single vanos. From my experience driving an s52 they are exceptionally linear in power delivery. On My car on the otherhand I can feel the kick as the vanos shifts. So my 2c is that it should feel very smooth. Although I don't own an m52


Glad she's on the road.



no...m50b25 like yours man. My previous vert was a m52. But ya, hoping i did not stuff up the vanos timing
 

danieljames

Active member
IIRC max power is somewhere around 5500~5700 rpm....i feel a shove around 3500.....and 5500 depending on what gear I'm in. Pulling first(not launching) feels abit donkey.
 

Peter@AEW

BMWFanatics Advertiser
Official Advertiser
Vanos comes in from 1000 can really be felt at 2000.
If you feeling it at 3500 something is wrong,stops working at roughly 5000
 

Nikhil

Honorary ///Member
Sounds like seals that need to be done, the transition should be fairly smooth.
 

ver328i

Well-known member
Could it not be related to the seals? I was rushing the whole process and decided not to buy a seal kit...:fencelook:

cant see what i did wrong...she idles really, really smooth
Timing was set at tdc...cams locked in place. Had the sprockets clocked to the right, then installed the vanos by turning the sprockets all the way to the left allowing the vanos piston to be sucked in all the way.

Whats the effects of tired vanos seals?
 

Peter@AEW

BMWFanatics Advertiser
Official Advertiser
They do not hold pressure so no positive engagement leading to loss of mid range as well as fuel economy.
 
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