Well id say dont panic and as suggested dont jump to conclusions just yet.
Get the codes read first.
There is a lot of scaremongering about VANOS units. It stems from the E46 M3 which do have an apetite for them and on these M3s replacement involves the removal of the cylinder head and the job ( parts and labour) comes to about £ 2500.00. Vanos units cannot be repaired. Incidentally the M3 only has one vanos unit on the inlet camshaft. You can tell a vanos unit is getting to the end of its life because it starts to growl as it gets worn. Rev the engine and let the revs drop.......... a little noise is ok.........a big growl is not and you should allow for a replacement when negotiating to buy. This subject is well documented.
M5 have two vanos units , one for each bank of the V8 and it appears i have just been unlicky , as my dealer says he has only repaced vanos units on a handfull of M5s. On the M5 the vanos fails mostly due to the hydraulic pressure pump failing as the vanos unit operates at a pressure of about 1000 psi ( im reliably informed). Now my vanos unit failed on start-up so there was no mechanical/ other damage , and what i would ask your dealer is do the units fail whilst on the move and if so does it cause any other damage ? If the answer is no , then i would get the codes read and if they all come back ok , then keep going until it fails. It may not.
Does the car feel any faster now the vanos has been replaced..? Marginaly.
good luck and dont worry
matt310 said:
Thanks for the replies. I am definitely getting the rough idle upon startup. The car still feels fast, but 400hp fast? I can't be sure.
I just had it in for an Inspection I at South Bay BMW and expressed my concerns about the rattling/tapping and they attributed it to valve lash. Hopefully now with the fault codes stored in the computer, they'll be able to determine the root cause.
I know the Vanos is the timing and lift system, which sounds like it could be a pretty major repair, which leads me to some questions:
1 - Is this something I need to pick and choose which dealership performs the work?
2 - Is the Vanos on this engine different than any other BMW engines from a design standpoint?
3 - Should only M-techs work on this type of repair and if so, how can I tell the dealership has them?
Thanks for any advice!
-Matt