2.5i VANOS issue?

[Zedebee]

Hi forum.

My 2.5i can be a little hesitant at low revs (<1500). At all other revs it is fine, so I try not to drive it there but am occasionally in the wrong gear. I have checked and cleaned the DISA which seems fine and can’t detect any air leaks. Is this a sign that the VANOS needs attention? If so what do you suggest?

Cheers, Z

[enuff_zed]

Hello, well firstly I'll ask what kind of code reader you have?
On my Autophix 5900 I can read a live data stream of the cam timing and it is simple to see if the cams are moving or not.
However, they only move away from idle. So maybe yours are slow to react?
As I'm sure you're aware, any M54 with over 50k on is likely to need a vanos overhaul anyway, but I cannot guarantee that this is your problem.
Could still be plugs, coils, MAF, air leaks, etc.

[Zedebee]

I have INPA on laptop and Creator 310+. Which menu am I looking at and what does good/bad look like? I don’t have any history with this car so unfortunately I don’t know what’s been done. Everything looks in good shape for 133k and runs great. Perhaps a slight stutter under the circumstances is normal, although my 3.0Si definitely doesn’t do it.

[enuff_zed]

I have INPA on laptop and Creator 310+. Which menu am I looking at and what does good/bad look like? I don’t have any history with this car so unfortunately I don’t know what’s been done. Everything looks in good shape for 133k and runs great. Perhaps a slight stutter under the circumstances is normal, although my 3.0Si definitely doesn’t do it.

The Autophix has a Datastream setting within the Engine menu. From that I select the vanos. Then it shows me Inlet and Exhaust angles. Not sure what they actually should be at idle, but I know they will vary considerably when you rev the engine.
The Project Cheapskate 3.0 has a very lumpy pick up and shows misfires. I know this could be plugs or coils, but the vanos data shows no movement at all on the cam angles, so I know that needs addressing. Whether it cures the misfires remains to be seen.

[Zedebee]

Good stuff. Just got back from a good run out today, I’ll run a diagnostic in the morning.

[bigwinn]

Hi forum.

My 2.5i can be a little hesitant at low revs (<1500). At all other revs it is fine, so I try not to drive it there but am occasionally in the wrong gear. I have checked and cleaned the DISA which seems fine and can’t detect any air leaks. Is this a sign that the VANOS needs attention? If so what do you suggest?

Cheers, Z

Ben does it do it only under load, low revs high gear etc?

I’ve had that a few times and it was coils starting to fail but don’t want to send you off down rabbit holes

[Zedebee]

Yes Stuart, that’s exactly it. No problem in 1st/2nd, just when you get caught napping in 3rd/4th. I’ll have a look at the VANOS on INPA tomorrow; if that checks out I’ll get a set of coils on standby.

[bigwinn]

Do you have ista? It’s much better at diagnosing a failing coil

[Zedebee]

Do you have ista? It’s much better at diagnosing a failing coil

Not as far I know. It didn’t come with the BCables suite which includes INPA, NCSExpert, WinKFP and Toolset32. Where do you get ISTA from?

[Zedebee]

Here is the data stream at idle.

4B89FAB6-502C-466C-BA6B-9344BEA9A545.jpeg (179.67 KiB) Viewed 363 times

The exhaust VANOS switches to 34.2 degrees at c.1250rpm but the inlet VANOS does nothing, I ran it all the way up to 5000rpm. MAF readings rise and fall with RPM, which suggests that’s OK. Do the VANOS readings suggest that the inlet solenoid (assuming there is one for inlet and one for exhaust) is not working? If so what is the suggested course of action?
Also, are the adaptions unusual and should I reset them?

[enuff_zed]

I would expect some inlet movement.
I think the solenoids are the same, so you could swap them and see what happens.
Or it could be the shuttle valve sticking (pop the solenoid off and push the valve in with your finger, it should move in easily and pop back out under spring pressure), or the seals knackered so that the oil just goes past the piston.
The adaptations are the ECU learning the particular idiosyncrasies of your engine. If you reset them it will run lumpy for a few minutes, then gradually improve over the next 100 miles or so. Unless the seals are goosed, then it'll struggle for a while until it learns to overcome that again.

[Zedebee]

Thanks Martin, I’ll try swapping/cleaning the solenoids. Are the BMW special tools 116420 and 322110 required to remove them?

[enuff_zed]

Thanks Martin, I’ll try swapping/cleaning the solenoids. Are the BMW special tools 116420 and 322110 required to remove them?

I just stuck a spanner on and unscrewed it.
All it consists of is an electrically operated plunger that pushes the valve in. When you unscrew the solenoid the valve stays in place. Though not all the oil does.

[bigwinn]

Thanks Martin, I’ll try swapping/cleaning the solenoids. Are the BMW special tools 116420 and 322110 required to remove them?

I just stuck a spanner on and unscrewed it.
All it consists of is an electrically operated plunger that pushes the valve in. When you unscrew the solenoid the valve stays in place. Though not all the oil does.

32mm spanner if I remember correctly

[enuff_zed]

Thanks Martin, I’ll try swapping/cleaning the solenoids. Are the BMW special tools 116420 and 322110 required to remove them?

I just stuck a spanner on and unscrewed it.
All it consists of is an electrically operated plunger that pushes the valve in. When you unscrew the solenoid the valve stays in place. Though not all the oil does.

32mm spanner if I remember correctly

I used an adjustable, but first time it wouldn't fit. Turned out I'd picked up the Imperial one not the Metric