E90 vanos issue

adolf hamster · 1 Sep 2017 at 13:44

Well, looks like i have this gem of a problem to deal with, she's running fine atm but if you give it the beans then you get a check engine warning and local garage saying its the vanos.

Bit of googling seems to suggest its an n52 thing and that it most often occurrs between 50 and 70k, with me being at 58k sounds about right.

Was wondering if anyone had any experience of this and how quickly it goes downhill? Ive got a fair bit of driving to do this weekend and i'd rather not be stuck in the back end of nowhere if it suddenly goes, currently you need to boot it to get the warning and itll go away after a couple of mins by itself.

I wont be able to get it sorted this week but if needs be i can cancel me driving plans if this is going to get worse quickly.

Psycho Sonny · 1 Sep 2017 at 13:54

if they say it's the vanos that sounds like a complete fail rather than just the seals being hard and shrunk like the older M54B30 engine which is a easy fix albeit time consuming.

i had my vanos re-built with new teflon seals (lifetime part) as the old ones are gone by 40K miles. it now should last forever.

the vanos is responsible for the timing of the engine much like hondas v-tec. it's not really something that should happen with high revs then disappear.

check your air filter and airbox are properly attached and not clogged up. could be your DISA valve. how do they know it's the vanos it's not easy to get to check it.

adolf hamster · 1 Sep 2017 at 14:45

They checked the obd fault code and came up with it being something to do with the vanos system.

Ive been doing my own reading and checked, apparently they changed the solenoid design and it has a new code- mine's the original code and i'd put money on them being the 2005 factory parts.

I was under the impression vanos was to do with throttle control? Changing valve lift instead of a conventional butterfly valve, although it makes sense you could use that for timing as well.

Im thinking possibly its early days of failing as aside from a slight blip on idle and the error when flooring it she's running smooth as ever.

Like i say, my main issue atm is wether or not i should worry about her quitting in the next few hundred miles and change my plans or if i'll be ok till i can get it sorted next week.

I'll check the airbox just in case a bird has decided to nest in it or something stupid

Gaygle · 1 Sep 2017 at 16:30

It would be very helpful if you got the error codes that the garage found.

adolf hamster · 1 Sep 2017 at 17:23

Gaygle said:
It would be very helpful if you got the error codes that the garage found.

I know, really need to add an obd reader to my long list of things i need to own. Wont be able to get anything more over the weekend.

Atm im thinking its most likely the solenoids, its the right age and it has the old versions of the solenoids to have that problem.

I hope its not the mechanical side, its only 58k so cant see it being worn out yet

adolf hamster · 5 Sep 2017 at 13:33

Damnit

So got new solenoids for her, just got them fitted and took her for a spin, once warmed up tried giving a bit of welly from a standstill (on a quiet backroad ofc) and nope, still pinging amber engine light once she made it into 3rd.

She sounded a bit rougher than normal while the error was in place, guessing maybe running rich in safe mode?

Once again error dissappears after a minute or so and she's back to normal running. Tested again at high revs but not full throttle and was absolutely fine.

Psycho Sonny · 5 Sep 2017 at 15:20

the way bmw sensors work they are constantly checking for errors all the time.

having a flat battery or a cheap crap battery can through up false positives on sensors on bmw's as the sensors don't get enough juice. why i replaced my cheap battery with top of the line.

you should be able to buy a vanos and get it fitted if it's failing.

adolf hamster · 5 Sep 2017 at 15:49

Hmm, battery i could have beleived a few days ago, as she'd been sitting a while and needed charged, but she's had plenty of running time now to get recharged, i'll stick her on overnight anyway see if it helps.

As for replacing the whole system isn't that basically a top end rebuild? That's gonna be one hell of a dent in the wallet if it comes to that.