Question on accumulator oil valve for vanos? - The Unofficial BMW M5 Messageboard (m5board.com)

m5 deamon · 28th February 2008, 21:12

Hello gentalmen,

I have used the search function and wound up empty handed on the info im looking for. I did a tsat on my beast yesterday and i noticed when i cracked the vanos line loose there was no oil a litte dribbled out. My initial thought was WTF

. So upon that i searched tis and it stated the there is a accumulator valve that stores oil upon shut down and opens upon start up and purges the vanos units. ok i thought then it must be normal for no oil to be in the line cause its in the valve. so i calmed down alittle but wanted to ask some of you vet guys on the board that have done your tsats yourself is that normal or if you guys had pressureized oil in the vanos line? and the particulars are my car is a 2001 m5 with 90455 miles I have no codes for vanos and on cold start up or after an oil change i do Not Have a vanos rattle. i am just curious if that is normal or if i should take pre emtive strike and change a 300 dollar valve and looking for your imput.

kind reguards
G

mottati · 28th February 2008, 21:17

i was under the impression that the accumulator stores oil under pressure for the initial cold start to reduce vanos noise. I would have thought you'd have oil under pressure if you open a line.
My 99k mile 00 had this accumulator done under warranty (it was not installed at the factory until 9/00 production, iirc), but over the past year, i've gotten more cold start rattle, so i too wonder if this could fail. It doesn't hurt anything, so there's no reason to replace it other than the noise.

m5 deamon · 28th February 2008, 21:29

moatti did you just do your tsat recently was there oil in the line

mottati · 28th February 2008, 22:05

Quote:

Originally Posted by m5 deamon

moatti did you just do your tsat recently was there oil in the line

i didn't do it myself.

gmakishima · 29th February 2008, 00:09

i read someplace that the vanos stores oil under extreme pressure... 200psi or so! if that's true, wouldn't it be extremely dangerous to disconnect any of those pressurized lines without first bleeding the pressure off? i heard bmw techs use the gt1 computer to open release the vanos pressure. does anyone know if this is true?

m5 deamon · 29th February 2008, 00:17

thats only if the car is running the pressure is that high. they use the gt1 to put the vanos into assembly mode and to operate the selinoids so they can bleed out the air in the system upon reassembly

m5 deamon · 29th February 2008, 17:15

bump

m5 deamon · 1st March 2008, 23:50

anyone ???? still havent found my answer