VANOS question

[DSK]

Since I bought my 328i it has been gradually getting flatter performance wise but the engine seems to run smoothly enough etc. I keep the engine well and fully serviced but the performance never got better. So I eventually got the thing hooked upto the engine diagnostics and worked through the list of faults.

1. Crackshaft Sensor - VANOS

I replaced the crankshaft sensor, went back on diagnostics and all was well and the car ran much better but still lacked somewhat in the performance department. Then a month later it went back on the diagnostics and it came up with;

2. Oxygen sensors BANK 1 & BANK 2 - VANOS

I put on a new catalytic converter and 2 new NGK/NTK 02 sensors and then hooked it upto the diagnostics again. It came up with no faults but the car didn't run much differently at all despite one of the old 02 sensors being pretty much snapped in half so a new set should have made some difference!

So I ran the car for a few more weeks and started to get the odd jerk whilst driving and then hooked it back upto the diagnostics and its showing the VANOS as being faulty. So can anyone tell me exactly what job the VANOS does? and what causes the VANOS to become faulty (these are supposed to be robust units to my understanding)?

Do you think that the engine will pick up better once the VANOS is replaced as the acceleration stays flat as the revs rise at the moment and my fuel consumption is a bit on the high side too? I am desperate to get the engine accelerating the way it is supposed to

 

[Kirby]

VANOS (Variable Nockenwellen Steuerung) is the mechanism responsible for changing the valve timing. At mid engine RPM, it advances the valve timing for better performance. It's a combination of electrical, hydraulic and mechanical parts. So it could be a $50 electrical part or a $500 - $1000 rebuild.

 

[epj3]

you prob have a bad vanos solenoid

 

[DSK]

I have never seen the inside of a VANOS unit so have no idea what would be inside one, but is there any way that a not very mechanically minded guy like myself can check the condition of the solenoid of the VANOS unit if i don't have to take anything apart?

Chances are I have to buy a brand new unit from BMW which is £240 (single VANOS) along with some gasket anyway. Would anyone know if this would come complete with all the electrical and mechanical bits and bobs that 'Kirby' mentioned or are they seperate components? (apologies to sound so dumb)

 

[B M W]

Go with what epj3 said. the vanos solenoid is a common problem in our vehicles.

 

[DSK]

Thanks, I am going to go to BMW tomorrow and see if I can get a solenoid and then I'll fit that and take it from there.

 

[epj3]

Woah you're nuts to order it from the dealer... aren't there any online parts places in the UK you can order from?

 

[DSK]

yeh, we do have some pretty good aftermarket distributors but they can't offer a VANOS as its a special order item and therefore a VANOS will end up costing me more through them than what I can get it for at the BMW dealership lol.

Contacted my uncle today and as we are in the motor trade he knows a close friend who works at a local BMW dealer and he's looking at the car for me on Saturday and I'll mention the solenoid to him.

 

[DSK]

Just to update you guys. I met my uncles friend who works at the local BMW dealership near our trade premises and he test drove the car noted that it was pretty much ok but could feel the lack in surge that I was complaining about. Whilt I was there with him, we went around the back and he hooked it upto the BMW diagnostics equipment and it stated that the VANOS has jammed in the past, but at the moment everything is working spot on but the air flow meter is running a bit lower than what it should do.

(Wow, this is a new dealership, used to be a BMW dealership but under a different name, and the workshop here is unlike anyone i have seen before!!!)

He is going to get me a price for a genuine BMW air flow meter through his discount at BMW as its likely to be better than my standard 'traders' discount. But either way I'll be getting a new air flow meter and will let you know if this solves the lack of performance and helps my fuel mileage